diff --git a/core/src/dsp/audio.h b/core/src/dsp/audio.h
index 795b58c3..d8575e43 100644
--- a/core/src/dsp/audio.h
+++ b/core/src/dsp/audio.h
@@ -12,9 +12,11 @@ namespace dsp {
             _in = in;
             generic_block<MonoToStereo>::registerInput(_in);
             generic_block<MonoToStereo>::registerOutput(&out);
+            generic_block<MonoToStereo>::_block_init = true;
         }
 
         void setInput(stream<float>* in) {
+            assert(generic_block<MonoToStereo>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<MonoToStereo>::ctrlMtx);
             generic_block<MonoToStereo>::tempStop();
             generic_block<MonoToStereo>::unregisterInput(_in);
@@ -53,9 +55,11 @@ namespace dsp {
             generic_block<ChannelsToStereo>::registerInput(_in_left);
             generic_block<ChannelsToStereo>::registerInput(_in_right);
             generic_block<ChannelsToStereo>::registerOutput(&out);
+            generic_block<ChannelsToStereo>::_block_init = true;
         }
 
         void setInput(stream<float>* in_left, stream<float>* in_right) {
+            assert(generic_block<ChannelsToStereo>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<ChannelsToStereo>::ctrlMtx);
             generic_block<ChannelsToStereo>::tempStop();
             generic_block<ChannelsToStereo>::unregisterInput(_in_left);
@@ -100,9 +104,11 @@ namespace dsp {
         StereoToMono(stream<stereo_t>* in) { init(in); }
 
         ~StereoToMono() {
+            if (!generic_block<StereoToMono>::_block_init) { return; }
             generic_block<StereoToMono>::stop();
             delete[] l_buf;
             delete[] r_buf;
+            generic_block<StereoToMono>::_block_init = false;
         }
 
         void init(stream<stereo_t>* in) {
@@ -111,9 +117,11 @@ namespace dsp {
             r_buf = new float[STREAM_BUFFER_SIZE];
             generic_block<StereoToMono>::registerInput(_in);
             generic_block<StereoToMono>::registerOutput(&out);
+            generic_block<StereoToMono>::_block_init = true;
         }
 
         void setInput(stream<stereo_t>* in) {
+            assert(generic_block<StereoToMono>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<StereoToMono>::ctrlMtx);
             generic_block<StereoToMono>::tempStop();
             generic_block<StereoToMono>::unregisterInput(_in);
@@ -155,9 +163,11 @@ namespace dsp {
             generic_block<StereoToChannels>::registerInput(_in);
             generic_block<StereoToChannels>::registerOutput(&out_left);
             generic_block<StereoToChannels>::registerOutput(&out_right);
+            generic_block<StereoToChannels>::_block_init = true;
         }
 
         void setInput(stream<stereo_t>* in) {
+            assert(generic_block<StereoToChannels>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<StereoToChannels>::ctrlMtx);
             generic_block<StereoToChannels>::tempStop();
             generic_block<StereoToChannels>::unregisterInput(_in);
diff --git a/core/src/dsp/block.h b/core/src/dsp/block.h
index 59b56bf7..2f8f5736 100644
--- a/core/src/dsp/block.h
+++ b/core/src/dsp/block.h
@@ -24,10 +24,13 @@ namespace dsp {
         virtual void init() {}
 
         virtual ~generic_block() {
+            if (!_block_init) { return; }
             stop();
+            _block_init = false;
         }
 
         virtual void start() {
+            assert(_block_init);
             std::lock_guard<std::mutex> lck(ctrlMtx);
             if (running) {
                 return;
@@ -37,6 +40,7 @@ namespace dsp {
         }
 
         virtual void stop() {
+            assert(_block_init);
             std::lock_guard<std::mutex> lck(ctrlMtx);
             if (!running) {
                 return;
@@ -46,6 +50,7 @@ namespace dsp {
         }
 
         void tempStart() {
+            assert(_block_init);
             if (tempStopped) {
                 doStart();
                 tempStopped = false;
@@ -53,13 +58,17 @@ namespace dsp {
         }
 
         void tempStop() {
+            assert(_block_init);
             if (running && !tempStopped) {
                 doStop();
                 tempStopped = true;
             }
         }
 
-        virtual int calcOutSize(int inSize) { return inSize; }
+        virtual int calcOutSize(int inSize) {
+            assert(_block_init);
+            return inSize;
+        }
 
         virtual int run() = 0;
         
@@ -119,17 +128,18 @@ namespace dsp {
             }
         }
 
+    protected:
+        bool _block_init = false;
+
+        std::mutex ctrlMtx;
+
         std::vector<untyped_steam*> inputs;
         std::vector<untyped_steam*> outputs;
 
         bool running = false;
         bool tempStopped = false;
-
         std::thread workerThread;
 
-    protected:
-        std::mutex ctrlMtx;
-
     };
 
     template <class BLOCK>
@@ -138,10 +148,13 @@ namespace dsp {
         virtual void init() {}
 
         virtual ~generic_hier_block() {
+            if (!_block_init) { return; }
             stop();
+            _block_init = false;
         }
 
         virtual void start() {
+            assert(_block_init);
             std::lock_guard<std::mutex> lck(ctrlMtx);
             if (running) {
                 return;
@@ -151,6 +164,7 @@ namespace dsp {
         }
 
         virtual void stop() {
+            assert(_block_init);
             std::lock_guard<std::mutex> lck(ctrlMtx);
             if (!running) {
                 return;
@@ -160,6 +174,7 @@ namespace dsp {
         }
 
         void tempStart() {
+            assert(_block_init);
             if (tempStopped) {
                 doStart();
                 tempStopped = false;
@@ -167,13 +182,17 @@ namespace dsp {
         }
 
         void tempStop() {
+            assert(_block_init);
             if (running && !tempStopped) {
                 doStop();
                 tempStopped = true;
             }
         }
 
-        virtual int calcOutSize(int inSize) { return inSize; }
+        virtual int calcOutSize(int inSize) {
+            assert(_block_init);
+            return inSize;
+        }
 
         friend BLOCK;
 
@@ -203,6 +222,7 @@ namespace dsp {
         bool running = false;
 
     protected:
+        bool _block_init = false;
         std::mutex ctrlMtx;
 
     };
diff --git a/core/src/dsp/buffer.h b/core/src/dsp/buffer.h
index a43c48e8..8a3f33af 100644
--- a/core/src/dsp/buffer.h
+++ b/core/src/dsp/buffer.h
@@ -12,7 +12,11 @@ namespace dsp {
 
         RingBuffer(int maxLatency) { init(maxLatency); }
 
-        ~RingBuffer() { delete _buffer; }
+        ~RingBuffer() {
+            if (!_init) { return; }
+            delete _buffer;
+            _init = false;
+        }
 
         void init(int maxLatency) {
             size = RING_BUF_SZ;
@@ -25,9 +29,11 @@ namespace dsp {
             readable = 0;
             writable = size;
             memset(_buffer, 0, size * sizeof(T));
+            _init = true;
         }
 
         int read(T* data, int len) {
+            assert(_init);
             int dataRead = 0;
             int toRead = 0;
             while (dataRead < len) {
@@ -57,6 +63,7 @@ namespace dsp {
         }
 
         int readAndSkip(T* data, int len, int skip) {
+            assert(_init);
             int dataRead = 0;
             int toRead = 0;
             while (dataRead < len) {
@@ -102,6 +109,7 @@ namespace dsp {
         }
 
         int waitUntilReadable() {
+            assert(_init);
             if (_stopReader) { return -1; }
             int _r = getReadable();
             if (_r != 0) { return _r; }
@@ -112,6 +120,7 @@ namespace dsp {
         }
 
         int getReadable(bool lock = true) {
+            assert(_init);
             if (lock) { _readable_mtx.lock(); };
             int _r = readable;
             if (lock) { _readable_mtx.unlock(); };
@@ -119,6 +128,7 @@ namespace dsp {
         }
 
         int write(T* data, int len) {
+            assert(_init);
             int dataWritten = 0;
             int toWrite = 0;
             while (dataWritten < len) {
@@ -149,6 +159,7 @@ namespace dsp {
         }
 
         int waitUntilwritable() {
+            assert(_init);
             if (_stopWriter) { return -1; }
             int _w = getWritable();
             if (_w != 0) { return _w; }
@@ -159,6 +170,7 @@ namespace dsp {
         }
 
         int getWritable(bool lock = true) {
+            assert(_init);
             if (lock) { _writable_mtx.lock(); };
             int _w = writable;
             if (lock) { _writable_mtx.unlock(); _readable_mtx.lock(); };
@@ -168,37 +180,45 @@ namespace dsp {
         }
 
         void stopReader() {
+            assert(_init);
             _stopReader = true;
             canReadVar.notify_one();
         }
 
         void stopWriter() {
+            assert(_init);
             _stopWriter = true;
             canWriteVar.notify_one();
         }
 
         bool getReadStop() {
+            assert(_init);
             return _stopReader;
         }
 
         bool getWriteStop() {
+            assert(_init);
             return _stopWriter;
         }
 
         void clearReadStop() {
+            assert(_init);
             _stopReader = false;
         }
 
         void clearWriteStop() {
+            assert(_init);
             _stopWriter = false;
         }
 
         void setMaxLatency(int maxLatency) {
+            assert(_init);
             this->maxLatency = maxLatency;
         }
 
     private:
-        T* _buffer = NULL;
+        bool _init = false;
+        T* _buffer;
         int size;
         int readc;
         int writec;
@@ -231,9 +251,11 @@ namespace dsp {
 
             generic_block<SampleFrameBuffer<T>>::registerInput(in);
             generic_block<SampleFrameBuffer<T>>::registerOutput(&out);
+            generic_block<SampleFrameBuffer<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<SampleFrameBuffer<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<SampleFrameBuffer<T>>::ctrlMtx);
             generic_block<SampleFrameBuffer<T>>::tempStop();
             generic_block<SampleFrameBuffer<T>>::unregisterInput(_in);
diff --git a/core/src/dsp/clock_recovery.h b/core/src/dsp/clock_recovery.h
index 5000fd9b..5189ec7e 100644
--- a/core/src/dsp/clock_recovery.h
+++ b/core/src/dsp/clock_recovery.h
@@ -7,6 +7,7 @@ namespace dsp {
     class EdgeTrigClockRecovery : public generic_block<EdgeTrigClockRecovery> {
     public:
         EdgeTrigClockRecovery() {}
+        
         EdgeTrigClockRecovery(stream<float>* in, int omega) { init(in, omega); }
 
         void init(stream<float>* in, int omega) {
@@ -14,9 +15,11 @@ namespace dsp {
             samplesPerSymbol = omega;
             generic_block<EdgeTrigClockRecovery>::registerInput(_in);
             generic_block<EdgeTrigClockRecovery>::registerOutput(&out);
+            generic_block<EdgeTrigClockRecovery>::_block_init = true;
         }
 
         void setInput(stream<float>* in) {
+            assert(generic_block<EdgeTrigClockRecovery>::_block_init);
             generic_block<EdgeTrigClockRecovery>::tempStop();
             generic_block<EdgeTrigClockRecovery>::unregisterInput(_in);
             _in = in;
@@ -69,6 +72,7 @@ namespace dsp {
     class MMClockRecovery : public generic_block<MMClockRecovery<T>> {
     public:
         MMClockRecovery() {}
+
         MMClockRecovery(stream<T>* in, float omega, float gainOmega, float muGain, float omegaRelLimit) {
             init(in, omega, gainOmega, muGain, omegaRelLimit);
         }
@@ -88,9 +92,11 @@ namespace dsp {
 
             generic_block<MMClockRecovery<T>>::registerInput(_in);
             generic_block<MMClockRecovery<T>>::registerOutput(&out);
+            generic_block<MMClockRecovery<T>>::_block_init = true;
         }
 
         void setOmega(float omega, float omegaRelLimit) {
+            assert(generic_block<MMClockRecovery<T>>::_block_init);
             generic_block<MMClockRecovery<T>>::tempStop();
             omegaMin = _omega - (_omega * _omegaRelLimit);
             omegaMax = _omega + (_omega * _omegaRelLimit);
@@ -100,6 +106,7 @@ namespace dsp {
         }
 
         void setGains(float omegaGain, float muGain) {
+            assert(generic_block<MMClockRecovery<T>>::_block_init);
             generic_block<MMClockRecovery<T>>::tempStop();
             _gainOmega = omegaGain;
             _muGain = muGain;
@@ -107,6 +114,7 @@ namespace dsp {
         }
 
         void setOmegaRelLimit(float omegaRelLimit) {
+            assert(generic_block<MMClockRecovery<T>>::_block_init);
             generic_block<MMClockRecovery<T>>::tempStop();
             _omegaRelLimit = omegaRelLimit;
             omegaMin = _omega - (_omega * _omegaRelLimit);
@@ -115,6 +123,7 @@ namespace dsp {
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<MMClockRecovery<T>>::_block_init);
             generic_block<MMClockRecovery<T>>::tempStop();
             generic_block<MMClockRecovery<T>>::unregisterInput(_in);
             _in = in;
diff --git a/core/src/dsp/convertion.h b/core/src/dsp/convertion.h
index 008b17af..519d70dd 100644
--- a/core/src/dsp/convertion.h
+++ b/core/src/dsp/convertion.h
@@ -14,9 +14,11 @@ namespace dsp {
             _in = in;
             generic_block<ComplexToStereo>::registerInput(_in);
             generic_block<ComplexToStereo>::registerOutput(&out);
+            generic_block<ComplexToStereo>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<ComplexToStereo>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<ComplexToStereo>::ctrlMtx);
             generic_block<ComplexToStereo>::tempStop();
             generic_block<ComplexToStereo>::unregisterInput(_in);
@@ -53,9 +55,11 @@ namespace dsp {
             _in = in;
             generic_block<ComplexToReal>::registerInput(_in);
             generic_block<ComplexToReal>::registerOutput(&out);
+            generic_block<ComplexToReal>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<ComplexToReal>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<ComplexToReal>::ctrlMtx);
             generic_block<ComplexToReal>::tempStop();
             generic_block<ComplexToReal>::unregisterInput(_in);
@@ -92,9 +96,11 @@ namespace dsp {
             _in = in;
             generic_block<ComplexToImag>::registerInput(_in);
             generic_block<ComplexToImag>::registerOutput(&out);
+            generic_block<ComplexToImag>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<ComplexToImag>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<ComplexToImag>::ctrlMtx);
             generic_block<ComplexToImag>::tempStop();
             generic_block<ComplexToImag>::unregisterInput(_in);
@@ -129,8 +135,10 @@ namespace dsp {
         RealToComplex(stream<float>* in) { init(in); }
 
         ~RealToComplex() {
+            if (!generic_block<RealToComplex>::_block_init) { return; }
             generic_block<RealToComplex>::stop();
             delete[] nullBuffer;
+            generic_block<RealToComplex>::_block_init = false;
         }
 
         void init(stream<float>* in) {
@@ -139,9 +147,11 @@ namespace dsp {
             memset(nullBuffer, 0, STREAM_BUFFER_SIZE * sizeof(float));
             generic_block<RealToComplex>::registerInput(_in);
             generic_block<RealToComplex>::registerOutput(&out);
+            generic_block<RealToComplex>::_block_init = true;
         }
 
         void setInput(stream<float>* in) {
+            assert(generic_block<RealToComplex>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<RealToComplex>::ctrlMtx);
             generic_block<RealToComplex>::tempStop();
             generic_block<RealToComplex>::unregisterInput(_in);
@@ -179,9 +189,11 @@ namespace dsp {
             _in = in;
             generic_block<Int16CToComplex>::registerInput(_in);
             generic_block<Int16CToComplex>::registerOutput(&out);
+            generic_block<Int16CToComplex>::_block_init = true;
         }
 
         void setInput(stream<int16_t>* in) {
+            assert(generic_block<Int16CToComplex>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Int16CToComplex>::ctrlMtx);
             generic_block<Int16CToComplex>::tempStop();
             generic_block<Int16CToComplex>::unregisterInput(_in);
diff --git a/core/src/dsp/deframing.h b/core/src/dsp/deframing.h
index 1daa72d9..1a6f9362 100644
--- a/core/src/dsp/deframing.h
+++ b/core/src/dsp/deframing.h
@@ -13,7 +13,9 @@ namespace dsp {
         Deframer(stream<uint8_t>* in, int frameLen, uint8_t* syncWord, int syncLen) { init(in, frameLen, syncWord, syncLen); }
 
         ~Deframer() {
+            if (!generic_block<Deframer>::_block_init) { return; }
             generic_block<Deframer>::stop();
+            generic_block<Deframer>::_block_init = false;
         }
 
         void init(stream<uint8_t>* in, int frameLen, uint8_t* syncWord, int syncLen) {
@@ -29,6 +31,17 @@ namespace dsp {
             
             generic_block<Deframer>::registerInput(_in);
             generic_block<Deframer>::registerOutput(&out);
+            generic_block<Deframer>::_block_init = true;
+        }
+
+        void setInput(stream<uint8_t>* in) {
+            assert(generic_block<Deframer>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Deframer>::ctrlMtx);
+            generic_block<Deframer>::tempStop();
+            generic_block<Deframer>::unregisterInput(_in);
+            _in = in;
+            generic_block<Deframer>::registerInput(_in);
+            generic_block<Deframer>::tempStart();
         }
 
         int run() {
@@ -148,6 +161,17 @@ namespace dsp {
             
             generic_block<ManchesterDeframer>::registerInput(_in);
             generic_block<ManchesterDeframer>::registerOutput(&out);
+            generic_block<ManchesterDeframer>::_block_init = true;
+        }
+
+        void setInput(stream<float>* in) {
+            assert(generic_block<ManchesterDeframer>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<ManchesterDeframer>::ctrlMtx);
+            generic_block<ManchesterDeframer>::tempStop();
+            generic_block<ManchesterDeframer>::unregisterInput(_in);
+            _in = in;
+            generic_block<ManchesterDeframer>::registerInput(_in);
+            generic_block<ManchesterDeframer>::tempStart();
         }
 
         int run() {
@@ -226,6 +250,17 @@ namespace dsp {
             
             generic_block<SymbolDeframer>::registerInput(_in);
             generic_block<SymbolDeframer>::registerOutput(&out);
+            generic_block<SymbolDeframer>::_block_init = true;
+        }
+
+        void setInput(stream<uint8_t>* in) {
+            assert(generic_block<SymbolDeframer>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<SymbolDeframer>::ctrlMtx);
+            generic_block<SymbolDeframer>::tempStop();
+            generic_block<SymbolDeframer>::unregisterInput(_in);
+            _in = in;
+            generic_block<SymbolDeframer>::registerInput(_in);
+            generic_block<SymbolDeframer>::tempStart();
         }
 
         int run() {
@@ -296,6 +331,17 @@ namespace dsp {
             _inverted = inverted;
             generic_block<ManchesterDecoder>::registerInput(_in);
             generic_block<ManchesterDecoder>::registerOutput(&out);
+            generic_block<ManchesterDecoder>::_block_init = true;
+        }
+
+        void setInput(stream<float>* in) {
+            assert(generic_block<ManchesterDecoder>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<ManchesterDecoder>::ctrlMtx);
+            generic_block<ManchesterDecoder>::tempStop();
+            generic_block<ManchesterDecoder>::unregisterInput(_in);
+            _in = in;
+            generic_block<ManchesterDecoder>::registerInput(_in);
+            generic_block<ManchesterDecoder>::tempStart();
         }
 
         int run() {
@@ -337,6 +383,17 @@ namespace dsp {
             
             generic_block<BitPacker>::registerInput(_in);
             generic_block<BitPacker>::registerOutput(&out);
+            generic_block<BitPacker>::_block_init = true;
+        }
+
+        void setInput(stream<uint8_t>* in) {
+            assert(generic_block<BitPacker>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<BitPacker>::ctrlMtx);
+            generic_block<BitPacker>::tempStop();
+            generic_block<BitPacker>::unregisterInput(_in);
+            _in = in;
+            generic_block<BitPacker>::registerInput(_in);
+            generic_block<BitPacker>::tempStart();
         }
 
         int run() {
diff --git a/core/src/dsp/demodulator.h b/core/src/dsp/demodulator.h
index 3c5ea4c1..8a93af09 100644
--- a/core/src/dsp/demodulator.h
+++ b/core/src/dsp/demodulator.h
@@ -44,9 +44,11 @@ namespace dsp {
             phasorSpeed = (2 * FL_M_PI) / (_sampleRate / _deviation);
             generic_block<FloatFMDemod>::registerInput(_in);
             generic_block<FloatFMDemod>::registerOutput(&out);
+            generic_block<FloatFMDemod>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<FloatFMDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FloatFMDemod>::ctrlMtx);
             generic_block<FloatFMDemod>::tempStop();
             generic_block<FloatFMDemod>::unregisterInput(_in);
@@ -56,6 +58,7 @@ namespace dsp {
         }
 
         void setSampleRate(float sampleRate) {
+            assert(generic_block<FloatFMDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FloatFMDemod>::ctrlMtx);
             generic_block<FloatFMDemod>::tempStop();
             _sampleRate = sampleRate;
@@ -64,10 +67,12 @@ namespace dsp {
         }
 
         float getSampleRate() {
+            assert(generic_block<FloatFMDemod>::_block_init);
             return _sampleRate;
         }
 
         void setDeviation(float deviation) {
+            assert(generic_block<FloatFMDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FloatFMDemod>::ctrlMtx);
             generic_block<FloatFMDemod>::tempStop();
             _deviation = deviation;
@@ -76,6 +81,7 @@ namespace dsp {
         }
 
         float getDeviation() {
+            assert(generic_block<FloatFMDemod>::_block_init);
             return _deviation;
         }
 
@@ -121,9 +127,11 @@ namespace dsp {
             phasorSpeed = (2 * FL_M_PI) / (_sampleRate / _deviation);
             generic_block<FMDemod>::registerInput(_in);
             generic_block<FMDemod>::registerOutput(&out);
+            generic_block<FMDemod>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<FMDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FMDemod>::ctrlMtx);
             generic_block<FMDemod>::tempStop();
             generic_block<FMDemod>::unregisterInput(_in);
@@ -133,6 +141,7 @@ namespace dsp {
         }
 
         void setSampleRate(float sampleRate) {
+            assert(generic_block<FMDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FMDemod>::ctrlMtx);
             generic_block<FMDemod>::tempStop();
             _sampleRate = sampleRate;
@@ -141,15 +150,18 @@ namespace dsp {
         }
 
         float getSampleRate() {
+            assert(generic_block<FMDemod>::_block_init);
             return _sampleRate;
         }
 
         void setDeviation(float deviation) {
+            assert(generic_block<FMDemod>::_block_init);
             _deviation = deviation;
             phasorSpeed = (2 * FL_M_PI) / (_sampleRate / _deviation);
         }
 
         float getDeviation() {
+            assert(generic_block<FMDemod>::_block_init);
             return _deviation;
         }
 
@@ -194,9 +206,11 @@ namespace dsp {
             _in = in;
             generic_block<AMDemod>::registerInput(_in);
             generic_block<AMDemod>::registerOutput(&out);
+            generic_block<AMDemod>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<AMDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<AMDemod>::ctrlMtx);
             generic_block<AMDemod>::tempStop();
             generic_block<AMDemod>::unregisterInput(_in);
@@ -237,8 +251,10 @@ namespace dsp {
         SSBDemod(stream<complex_t>* in, float sampleRate, float bandWidth, int mode) { init(in, sampleRate, bandWidth, mode); }
 
         ~SSBDemod() {
+            if (!generic_block<SSBDemod>::_block_init) { return; }
             generic_block<SSBDemod>::stop();
             delete[] buffer;
+            generic_block<SSBDemod>::_block_init = false;
         }
 
         enum {
@@ -267,9 +283,11 @@ namespace dsp {
             buffer = new lv_32fc_t[STREAM_BUFFER_SIZE];
             generic_block<SSBDemod>::registerInput(_in);
             generic_block<SSBDemod>::registerOutput(&out);
+            generic_block<SSBDemod>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<SSBDemod>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<SSBDemod>::ctrlMtx);
             generic_block<SSBDemod>::tempStop();
             generic_block<SSBDemod>::unregisterInput(_in);
@@ -279,7 +297,7 @@ namespace dsp {
         }
 
         void setSampleRate(float sampleRate) {
-            // No need to restart
+            assert(generic_block<SSBDemod>::_block_init);
             _sampleRate = sampleRate;
             switch (_mode) {
             case MODE_USB:
@@ -295,7 +313,7 @@ namespace dsp {
         }
 
         void setBandWidth(float bandWidth) {
-            // No need to restart
+            assert(generic_block<SSBDemod>::_block_init);
             _bandWidth = bandWidth;
             switch (_mode) {
             case MODE_USB:
@@ -311,6 +329,7 @@ namespace dsp {
         }
 
         void setMode(int mode) {
+            assert(generic_block<SSBDemod>::_block_init);
             _mode = mode;
             switch (_mode) {
             case MODE_USB:
@@ -352,6 +371,7 @@ namespace dsp {
     class MSKDemod : public generic_hier_block<MSKDemod> {
     public:
         MSKDemod() {}
+
         MSKDemod(stream<complex_t>* input, float sampleRate, float deviation, float baudRate, float omegaGain = (0.01*0.01) / 4, float muGain = 0.01f, float omegaRelLimit = 0.005f) {
             init(input, sampleRate, deviation, baudRate, omegaGain, muGain, omegaRelLimit);
         }
@@ -370,9 +390,11 @@ namespace dsp {
 
             generic_hier_block<MSKDemod>::registerBlock(&demod);
             generic_hier_block<MSKDemod>::registerBlock(&recov);
+            generic_hier_block<MSKDemod>::_block_init = true;
         }
 
         void setSampleRate(float sampleRate) {
+            assert(generic_hier_block<MSKDemod>::_block_init);
             generic_hier_block<MSKDemod>::tempStop();
             _sampleRate = sampleRate;
             demod.setSampleRate(_sampleRate);
@@ -381,23 +403,27 @@ namespace dsp {
         }
 
         void setDeviation(float deviation) {
+            assert(generic_hier_block<MSKDemod>::_block_init);
             _deviation = deviation;
             demod.setDeviation(deviation);
         }
 
         void setBaudRate(float baudRate, float omegaRelLimit) {
+            assert(generic_hier_block<MSKDemod>::_block_init);
             _baudRate = baudRate;
             _omegaRelLimit = omegaRelLimit;
             recov.setOmega(_sampleRate / _baudRate, _omegaRelLimit);
         }
 
         void setMMGains(float omegaGain, float myGain) {
+            assert(generic_hier_block<MSKDemod>::_block_init);
             _omegaGain = omegaGain;
             _muGain = myGain;
             recov.setGains(_omegaGain, _muGain);
         }
 
         void setOmegaRelLimit(float omegaRelLimit) {
+            assert(generic_hier_block<MSKDemod>::_block_init);
             _omegaRelLimit = omegaRelLimit;
             recov.setOmegaRelLimit(_omegaRelLimit);
         }
@@ -420,6 +446,7 @@ namespace dsp {
     class PSKDemod : public generic_hier_block<PSKDemod<ORDER, OFFSET>> {
     public:
         PSKDemod() {}
+
         PSKDemod(stream<complex_t>* input, float sampleRate, float baudRate, int RRCTapCount = 31, float RRCAlpha = 0.32f, float agcRate = 10e-4, float costasLoopBw = 0.004f, float omegaGain = (0.01*0.01) / 4, float muGain = 0.01f, float omegaRelLimit = 0.005f) {
             init(input, sampleRate, baudRate, RRCTapCount, RRCAlpha, agcRate, costasLoopBw, omegaGain, muGain, omegaRelLimit);
         }
@@ -456,13 +483,17 @@ namespace dsp {
             generic_hier_block<PSKDemod<ORDER, OFFSET>>::registerBlock(&recov);
 
             out = &recov.out;
+
+            generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* input) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             agc.setInput(input);
         }
 
         void setSampleRate(float sampleRate) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _sampleRate = sampleRate;
             rrc.tempStop();
             recov.tempStop();
@@ -474,6 +505,7 @@ namespace dsp {
         }
 
         void setBaudRate(float baudRate) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _baudRate = baudRate;
             rrc.tempStop();
             recov.tempStop();
@@ -485,6 +517,7 @@ namespace dsp {
         }
 
         void setRRCParams(int RRCTapCount, float RRCAlpha) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _RRCTapCount = RRCTapCount;
             _RRCAlpha = RRCAlpha;
             taps.setTapCount(_RRCTapCount);
@@ -493,22 +526,26 @@ namespace dsp {
         }
 
         void setAgcRate(float agcRate) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _agcRate = agcRate;
             agc.setRate(_agcRate);
         }
 
         void setCostasLoopBw(float costasLoopBw) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _costasLoopBw = costasLoopBw;
             demod.setLoopBandwidth(_costasLoopBw);
         }
 
         void setMMGains(float omegaGain, float myGain) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _omegaGain = omegaGain;
             _muGain = myGain;
             recov.setGains(_omegaGain, _muGain);
         }
 
         void setOmegaRelLimit(float omegaRelLimit) {
+            assert((generic_hier_block<PSKDemod<ORDER, OFFSET>>::_block_init));
             _omegaRelLimit = omegaRelLimit;
             recov.setOmegaRelLimit(_omegaRelLimit);
         }
@@ -537,6 +574,7 @@ namespace dsp {
     class PMDemod : public generic_hier_block<PMDemod> {
     public:
         PMDemod() {}
+
         PMDemod(stream<complex_t>* input, float sampleRate, float baudRate, float agcRate = 0.02e-3f, float pllLoopBandwidth = (0.06f*0.06f) / 4.0f, int rrcTapCount = 31, float rrcAlpha = 0.6f, float omegaGain = (0.01*0.01) / 4, float muGain = 0.01f, float omegaRelLimit = 0.005f) {
             init(input, sampleRate, baudRate, agcRate, pllLoopBandwidth, rrcTapCount, rrcAlpha, omegaGain, muGain, omegaRelLimit);
         }
@@ -564,23 +602,28 @@ namespace dsp {
             generic_hier_block<PMDemod>::registerBlock(&pll);
             generic_hier_block<PMDemod>::registerBlock(&rrc);
             generic_hier_block<PMDemod>::registerBlock(&recov);
+            generic_hier_block<PMDemod>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* input) {
+            assert(generic_hier_block<PMDemod>::_block_init);
             agc.setInput(input);
         }
 
         void setAgcRate(float agcRate) {
+            assert(generic_hier_block<PMDemod>::_block_init);
             _agcRate = agcRate;
             agc.setRate(_agcRate);
         }
 
         void setPllLoopBandwidth(float pllLoopBandwidth) {
+            assert(generic_hier_block<PMDemod>::_block_init);
             _pllLoopBandwidth = pllLoopBandwidth;
             pll.setLoopBandwidth(_pllLoopBandwidth);
         }
 
         void setRRCParams(int rrcTapCount, float rrcAlpha) {
+            assert(generic_hier_block<PMDemod>::_block_init);
             _rrcTapCount = rrcTapCount;
             _rrcAlpha = rrcAlpha;
             rrcwin.setTapCount(_rrcTapCount);
@@ -589,12 +632,14 @@ namespace dsp {
         }
 
         void setMMGains(float omegaGain, float muGain) {
+            assert(generic_hier_block<PMDemod>::_block_init);
             _omegaGain = omegaGain;
             _muGain = muGain;
             recov.setGains(_omegaGain, _muGain);
         }
 
         void setOmegaRelLimit(float omegaRelLimit) {
+            assert(generic_hier_block<PMDemod>::_block_init);
             _omegaRelLimit = omegaRelLimit;
             recov.setOmegaRelLimit(_omegaRelLimit);
         }
diff --git a/core/src/dsp/falcon_fec.h b/core/src/dsp/falcon_fec.h
index 560895d6..8c579735 100644
--- a/core/src/dsp/falcon_fec.h
+++ b/core/src/dsp/falcon_fec.h
@@ -62,10 +62,6 @@ namespace dsp {
 
         FalconRS(stream<uint8_t>* in) { init(in); }
 
-        ~FalconRS() {
-            generic_block<FalconRS>::stop();
-        }
-
         void init(stream<uint8_t>* in) {
             _in = in;
 
@@ -76,6 +72,17 @@ namespace dsp {
             
             generic_block<FalconRS>::registerInput(_in);
             generic_block<FalconRS>::registerOutput(&out);
+            generic_block<FalconRS>::_block_init = true;
+        }
+
+        void setInput(stream<uint8_t>* in) {
+            assert(generic_block<FalconRS>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<FalconRS>::ctrlMtx);
+            generic_block<FalconRS>::tempStop();
+            generic_block<FalconRS>::unregisterInput(_in);
+            _in = in;
+            generic_block<FalconRS>::registerInput(_in);
+            generic_block<FalconRS>::tempStart();
         }
 
         int run() {
diff --git a/core/src/dsp/falcon_packet.h b/core/src/dsp/falcon_packet.h
index e1d7aca9..c4cdce5e 100644
--- a/core/src/dsp/falcon_packet.h
+++ b/core/src/dsp/falcon_packet.h
@@ -14,15 +14,22 @@ namespace dsp {
 
         FalconPacketSync(stream<uint8_t>* in) { init(in); }
 
-        ~FalconPacketSync() {
-            generic_block<FalconPacketSync>::stop();
-        }
-
         void init(stream<uint8_t>* in) {
             _in = in;
             
             generic_block<FalconPacketSync>::registerInput(_in);
             generic_block<FalconPacketSync>::registerOutput(&out);
+            generic_block<FalconPacketSync>::_block_init = true;
+        }
+
+        void setInput(stream<uint8_t>* in) {
+            assert(generic_block<FalconPacketSync>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<FalconPacketSync>::ctrlMtx);
+            generic_block<FalconPacketSync>::tempStop();
+            generic_block<FalconPacketSync>::unregisterInput(_in);
+            _in = in;
+            generic_block<FalconPacketSync>::registerInput(_in);
+            generic_block<FalconPacketSync>::tempStart();
         }
 
         int run() {
diff --git a/core/src/dsp/filter.h b/core/src/dsp/filter.h
index e02bd71e..404e9107 100644
--- a/core/src/dsp/filter.h
+++ b/core/src/dsp/filter.h
@@ -13,9 +13,11 @@ namespace dsp {
         FIR(stream<T>* in, dsp::filter_window::generic_window* window) { init(in, window); }
 
         ~FIR() {
+            if (!generic_block<FIR<T>>::_block_init) { return; }
             generic_block<FIR<T>>::stop();
             volk_free(buffer);
             volk_free(taps);
+            generic_block<FIR<T>>::_block_init = false;
         }
 
         void init(stream<T>* in, dsp::filter_window::generic_window* window) {
@@ -29,9 +31,11 @@ namespace dsp {
             bufStart = &buffer[tapCount];
             generic_block<FIR<T>>::registerInput(_in);
             generic_block<FIR<T>>::registerOutput(&out);
+            generic_block<FIR<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<FIR<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FIR<T>>::ctrlMtx);
             generic_block<FIR<T>>::tempStop();
             generic_block<FIR<T>>::unregisterInput(_in);
@@ -41,6 +45,7 @@ namespace dsp {
         }
 
         void updateWindow(dsp::filter_window::generic_window* window) {
+            assert(generic_block<FIR<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FIR<T>>::ctrlMtx);
             _window = window;
             volk_free(taps);
@@ -99,8 +104,6 @@ namespace dsp {
 
         BFMDeemp(stream<stereo_t>* in, float sampleRate, float tau) { init(in, sampleRate, tau); }
 
-        ~BFMDeemp() { generic_block<BFMDeemp>::stop(); }
-
         void init(stream<stereo_t>* in, float sampleRate, float tau) {
             _in = in;
             _sampleRate = sampleRate;
@@ -109,9 +112,11 @@ namespace dsp {
             alpha = dt / (_tau + dt);
             generic_block<BFMDeemp>::registerInput(_in);
             generic_block<BFMDeemp>::registerOutput(&out);
+            generic_block<BFMDeemp>::_block_init = true;
         }
 
         void setInput(stream<stereo_t>* in) {
+            assert(generic_block<BFMDeemp>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<BFMDeemp>::ctrlMtx);
             generic_block<BFMDeemp>::tempStop();
             generic_block<BFMDeemp>::unregisterInput(_in);
@@ -121,12 +126,14 @@ namespace dsp {
         }
 
         void setSampleRate(float sampleRate) {
+            assert(generic_block<BFMDeemp>::_block_init);
             _sampleRate = sampleRate;
             float dt = 1.0f / _sampleRate;
             alpha = dt / (_tau + dt);
         }
 
         void setTau(float tau) {
+            assert(generic_block<BFMDeemp>::_block_init);
             _tau = tau;
             float dt = 1.0f / _sampleRate;
             alpha = dt / (_tau + dt);
diff --git a/core/src/dsp/math.h b/core/src/dsp/math.h
index 62241d1f..f4b07c4a 100644
--- a/core/src/dsp/math.h
+++ b/core/src/dsp/math.h
@@ -16,6 +16,40 @@ namespace dsp {
             generic_block<Add<T>>::registerInput(a);
             generic_block<Add<T>>::registerInput(b);
             generic_block<Add<T>>::registerOutput(&out);
+            generic_block<Add<T>>::_block_init = true;
+        }
+
+        void setInputs(stream<T>* a, stream<T>* b) {
+            assert(generic_block<Add<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Add<T>>::ctrlMtx);
+            generic_block<Add<T>>::tempStop();
+            generic_block<Add<T>>::unregisterInput(_a);
+            generic_block<Add<T>>::unregisterInput(_b);
+            _a = a;
+            _b = b;
+            generic_block<Add<T>>::registerInput(_a);
+            generic_block<Add<T>>::registerInput(_b);
+            generic_block<Add<T>>::tempStart();
+        }
+
+        void setInputA(stream<T>* a) {
+            assert(generic_block<Add<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Add<T>>::ctrlMtx);
+            generic_block<Add<T>>::tempStop();
+            generic_block<Add<T>>::unregisterInput(_a);
+            _a = a;
+            generic_block<Add<T>>::registerInput(_a);
+            generic_block<Add<T>>::tempStart();
+        }
+
+        void setInputB(stream<T>* b) {
+            assert(generic_block<Add<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Add<T>>::ctrlMtx);
+            generic_block<Add<T>>::tempStop();
+            generic_block<Add<T>>::unregisterInput(_b);
+            _b = b;
+            generic_block<Add<T>>::registerInput(_b);
+            generic_block<Add<T>>::tempStart();
         }
 
         int run() {
@@ -51,18 +85,52 @@ namespace dsp {
     };
 
     template <class T>
-    class Substract : public generic_block<Substract<T>> {
+    class Subtract : public generic_block<Subtract<T>> {
     public:
-        Substract() {}
+        Subtract() {}
 
-        Substract(stream<T>* a, stream<T>* b) { init(a, b); }
+        Subtract(stream<T>* a, stream<T>* b) { init(a, b); }
 
         void init(stream<T>* a, stream<T>* b) {
             _a = a;
             _b = b;
-            generic_block<Substract<T>>::registerInput(a);
-            generic_block<Substract<T>>::registerInput(b);
-            generic_block<Substract<T>>::registerOutput(&out);
+            generic_block<Subtract<T>>::registerInput(a);
+            generic_block<Subtract<T>>::registerInput(b);
+            generic_block<Subtract<T>>::registerOutput(&out);
+            generic_block<Subtract<T>>::_block_init = true;
+        }
+
+        void setInputs(stream<T>* a, stream<T>* b) {
+            assert(generic_block<Subtract<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Subtract<T>>::ctrlMtx);
+            generic_block<Subtract<T>>::tempStop();
+            generic_block<Subtract<T>>::unregisterInput(_a);
+            generic_block<Subtract<T>>::unregisterInput(_b);
+            _a = a;
+            _b = b;
+            generic_block<Subtract<T>>::registerInput(_a);
+            generic_block<Subtract<T>>::registerInput(_b);
+            generic_block<Subtract<T>>::tempStart();
+        }
+
+        void setInputA(stream<T>* a) {
+            assert(generic_block<Subtract<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Subtract<T>>::ctrlMtx);
+            generic_block<Subtract<T>>::tempStop();
+            generic_block<Subtract<T>>::unregisterInput(_a);
+            _a = a;
+            generic_block<Subtract<T>>::registerInput(_a);
+            generic_block<Subtract<T>>::tempStart();
+        }
+
+        void setInputB(stream<T>* b) {
+            assert(generic_block<Subtract<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Subtract<T>>::ctrlMtx);
+            generic_block<Subtract<T>>::tempStop();
+            generic_block<Subtract<T>>::unregisterInput(_b);
+            _b = b;
+            generic_block<Subtract<T>>::registerInput(_b);
+            generic_block<Subtract<T>>::tempStart();
         }
 
         int run() {
@@ -110,6 +178,40 @@ namespace dsp {
             generic_block<Multiply>::registerInput(a);
             generic_block<Multiply>::registerInput(b);
             generic_block<Multiply>::registerOutput(&out);
+            generic_block<Multiply>::_block_init = true;
+        }
+
+        void setInputs(stream<T>* a, stream<T>* b) {
+            assert(generic_block<Multiply<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Multiply<T>>::ctrlMtx);
+            generic_block<Multiply<T>>::tempStop();
+            generic_block<Multiply<T>>::unregisterInput(_a);
+            generic_block<Multiply<T>>::unregisterInput(_b);
+            _a = a;
+            _b = b;
+            generic_block<Multiply<T>>::registerInput(_a);
+            generic_block<Multiply<T>>::registerInput(_b);
+            generic_block<Multiply<T>>::tempStart();
+        }
+
+        void setInputA(stream<T>* a) {
+            assert(generic_block<Multiply<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Multiply<T>>::ctrlMtx);
+            generic_block<Multiply<T>>::tempStop();
+            generic_block<Multiply<T>>::unregisterInput(_a);
+            _a = a;
+            generic_block<Multiply<T>>::registerInput(_a);
+            generic_block<Multiply<T>>::tempStart();
+        }
+
+        void setInputB(stream<T>* b) {
+            assert(generic_block<Multiply<T>>::_block_init);
+            std::lock_guard<std::mutex> lck(generic_block<Multiply<T>>::ctrlMtx);
+            generic_block<Multiply<T>>::tempStop();
+            generic_block<Multiply<T>>::unregisterInput(_b);
+            _b = b;
+            generic_block<Multiply<T>>::registerInput(_b);
+            generic_block<Multiply<T>>::tempStart();
         }
 
         int run() {
diff --git a/core/src/dsp/measure.h b/core/src/dsp/measure.h
index 2abe7557..fa1a8721 100644
--- a/core/src/dsp/measure.h
+++ b/core/src/dsp/measure.h
@@ -16,9 +16,11 @@ namespace dsp {
         void init(stream<stereo_t>* in) {
             _in = in;
             generic_block<LevelMeter>::registerInput(_in);
+            generic_block<LevelMeter>::_block_init = true;
         }
 
         void setInput(stream<stereo_t>* in) {
+            assert(generic_block<LevelMeter>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<LevelMeter>::ctrlMtx);
             generic_block<LevelMeter>::tempStop();
             generic_block<LevelMeter>::unregisterInput(_in);
diff --git a/core/src/dsp/meteor/hrpt.h b/core/src/dsp/meteor/hrpt.h
index 33ca08c4..74c14064 100644
--- a/core/src/dsp/meteor/hrpt.h
+++ b/core/src/dsp/meteor/hrpt.h
@@ -18,9 +18,11 @@ namespace dsp {
                 generic_block<HRPTDemux>::registerOutput(&SSPDOut);
                 generic_block<HRPTDemux>::registerOutput(&MTVZAOut);
                 generic_block<HRPTDemux>::registerOutput(&MSUMROut);
+                generic_block<HRPTDemux>::_block_init = true;
             }
 
             void setInput(stream<uint8_t>* in) {
+                assert(generic_block<HRPTDemux>::_block_init);
                 std::lock_guard<std::mutex> lck(generic_block<HRPTDemux>::ctrlMtx);
                 generic_block<HRPTDemux>::tempStop();
                 generic_block<HRPTDemux>::unregisterInput(_in);
diff --git a/core/src/dsp/meteor/msumr.h b/core/src/dsp/meteor/msumr.h
index 10195adf..d05e4925 100644
--- a/core/src/dsp/meteor/msumr.h
+++ b/core/src/dsp/meteor/msumr.h
@@ -22,9 +22,11 @@ namespace dsp {
                 generic_block<MSUMRDemux>::registerOutput(&msumr4Out);
                 generic_block<MSUMRDemux>::registerOutput(&msumr5Out);
                 generic_block<MSUMRDemux>::registerOutput(&msumr6Out);
+                generic_block<MSUMRDemux>::_block_init = true;
             }
 
             void setInput(stream<uint8_t>* in) {
+                assert(generic_block<MSUMRDemux>::_block_init);
                 std::lock_guard<std::mutex> lck(generic_block<MSUMRDemux>::ctrlMtx);
                 generic_block<MSUMRDemux>::tempStop();
                 generic_block<MSUMRDemux>::unregisterInput(_in);
diff --git a/core/src/dsp/noaa/hrpt.h b/core/src/dsp/noaa/hrpt.h
index e28ba3db..4c4a4ae8 100644
--- a/core/src/dsp/noaa/hrpt.h
+++ b/core/src/dsp/noaa/hrpt.h
@@ -31,9 +31,11 @@ namespace dsp {
                 generic_block<HRPTDemux>::registerOutput(&AVHRRChan3Out);
                 generic_block<HRPTDemux>::registerOutput(&AVHRRChan4Out);
                 generic_block<HRPTDemux>::registerOutput(&AVHRRChan5Out);
+                generic_block<HRPTDemux>::_block_init = true;
             }
 
             void setInput(stream<uint8_t>* in) {
+                assert(generic_block<HRPTDemux>::_block_init);
                 std::lock_guard<std::mutex> lck(generic_block<HRPTDemux>::ctrlMtx);
                 generic_block<HRPTDemux>::tempStop();
                 generic_block<HRPTDemux>::unregisterInput(_in);
diff --git a/core/src/dsp/noaa/tip.h b/core/src/dsp/noaa/tip.h
index c7bf7e18..6467a095 100644
--- a/core/src/dsp/noaa/tip.h
+++ b/core/src/dsp/noaa/tip.h
@@ -17,9 +17,11 @@ namespace dsp {
                 generic_block<TIPDemux>::registerOutput(&SEMOut);
                 generic_block<TIPDemux>::registerOutput(&DCSOut);
                 generic_block<TIPDemux>::registerOutput(&SBUVOut);
+                generic_block<TIPDemux>::_block_init = true;
             }
 
             void setInput(stream<uint8_t>* in) {
+                assert(generic_block<TIPDemux>::_block_init);
                 std::lock_guard<std::mutex> lck(generic_block<TIPDemux>::ctrlMtx);
                 generic_block<TIPDemux>::tempStop();
                 generic_block<TIPDemux>::unregisterInput(_in);
diff --git a/core/src/dsp/pll.h b/core/src/dsp/pll.h
index 025657af..5ab22b1e 100644
--- a/core/src/dsp/pll.h
+++ b/core/src/dsp/pll.h
@@ -10,6 +10,7 @@ namespace dsp {
     class CostasLoop: public generic_block<CostasLoop<ORDER>> {
     public:
         CostasLoop() {}
+
         CostasLoop(stream<complex_t>* in, float loopBandwidth) { init(in, loopBandwidth); }
 
         void init(stream<complex_t>* in, float loopBandwidth) {
@@ -25,9 +26,11 @@ namespace dsp {
 
             generic_block<CostasLoop<ORDER>>::registerInput(_in);
             generic_block<CostasLoop<ORDER>>::registerOutput(&out);
+            generic_block<CostasLoop<ORDER>>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<CostasLoop<ORDER>>::_block_init);
             generic_block<CostasLoop<ORDER>>::tempStop();
             generic_block<CostasLoop<ORDER>>::unregisterInput(_in);
             _in = in;
@@ -36,6 +39,7 @@ namespace dsp {
         }
 
         void setLoopBandwidth(float loopBandwidth) {
+            assert(generic_block<CostasLoop<ORDER>>::_block_init);
             generic_block<CostasLoop<ORDER>>::tempStop();
             _loopBandwidth = loopBandwidth;
             float dampningFactor = sqrtf(2.0f) / 2.0f;
@@ -121,6 +125,7 @@ namespace dsp {
     class CarrierTrackingPLL: public generic_block<CarrierTrackingPLL<T>> {
     public:
         CarrierTrackingPLL() {}
+
         CarrierTrackingPLL(stream<complex_t>* in, float loopBandwidth) { init(in, loopBandwidth); }
 
         void init(stream<complex_t>* in, float loopBandwidth) {
@@ -136,9 +141,11 @@ namespace dsp {
 
             generic_block<CarrierTrackingPLL<T>>::registerInput(_in);
             generic_block<CarrierTrackingPLL<T>>::registerOutput(&out);
+            generic_block<CarrierTrackingPLL<T>>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<CarrierTrackingPLL<T>>::_block_init);
             generic_block<CarrierTrackingPLL<T>>::tempStop();
             generic_block<CarrierTrackingPLL<T>>::unregisterInput(_in);
             _in = in;
@@ -147,6 +154,7 @@ namespace dsp {
         }
 
         void setLoopBandwidth(float loopBandwidth) {
+            assert(generic_block<CarrierTrackingPLL<T>>::_block_init);
             generic_block<CarrierTrackingPLL<T>>::tempStop();
             _loopBandwidth = loopBandwidth;
             float dampningFactor = sqrtf(2.0f) / 2.0f;
@@ -224,6 +232,7 @@ namespace dsp {
     class PLL: public generic_block<PLL> {
     public:
         PLL() {}
+
         PLL(stream<complex_t>* in, float loopBandwidth) { init(in, loopBandwidth); }
 
         void init(stream<complex_t>* in, float loopBandwidth) {
@@ -239,9 +248,11 @@ namespace dsp {
 
             generic_block<PLL>::registerInput(_in);
             generic_block<PLL>::registerOutput(&out);
+            generic_block<PLL>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<PLL>::_block_init);
             generic_block<PLL>::tempStop();
             generic_block<PLL>::unregisterInput(_in);
             _in = in;
@@ -250,6 +261,7 @@ namespace dsp {
         }
 
         void setLoopBandwidth(float loopBandwidth) {
+            assert(generic_block<PLL>::_block_init);
             generic_block<PLL>::tempStop();
             _loopBandwidth = loopBandwidth;
             float dampningFactor = sqrtf(2.0f) / 2.0f;
diff --git a/core/src/dsp/processing.h b/core/src/dsp/processing.h
index 87e95734..f8c23047 100644
--- a/core/src/dsp/processing.h
+++ b/core/src/dsp/processing.h
@@ -22,9 +22,11 @@ namespace dsp {
             phaseDelta = lv_cmake(std::cos((_freq / _sampleRate) * 2.0f * FL_M_PI), std::sin((_freq / _sampleRate) * 2.0f * FL_M_PI));
             generic_block<FrequencyXlator<T>>::registerInput(_in);
             generic_block<FrequencyXlator<T>>::registerOutput(&out);
+            generic_block<FrequencyXlator<T>>::_block_init = true;
         }
 
-        void setInputSize(stream<complex_t>* in) {
+        void setInput(stream<complex_t>* in) {
+            assert(generic_block<FrequencyXlator<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FrequencyXlator<T>>::ctrlMtx);
             generic_block<FrequencyXlator<T>>::tempStop();
             generic_block<FrequencyXlator<T>>::unregisterInput(_in);
@@ -34,22 +36,24 @@ namespace dsp {
         }
 
         void setSampleRate(float sampleRate) {
-            // No need to restart
+            assert(generic_block<FrequencyXlator<T>>::_block_init);
             _sampleRate = sampleRate;
             phaseDelta = lv_cmake(std::cos((_freq / _sampleRate) * 2.0f * FL_M_PI), std::sin((_freq / _sampleRate) * 2.0f * FL_M_PI));
         }
 
         float getSampleRate() {
+            assert(generic_block<FrequencyXlator<T>>::_block_init);
             return _sampleRate;
         }
 
         void setFrequency(float freq) {
-            // No need to restart
+            assert(generic_block<FrequencyXlator<T>>::_block_init);
             _freq = freq;
             phaseDelta = lv_cmake(std::cos((_freq / _sampleRate) * 2.0f * FL_M_PI), std::sin((_freq / _sampleRate) * 2.0f * FL_M_PI));
         }
 
         float getFrequency() {
+            assert(generic_block<FrequencyXlator<T>>::_block_init);
             return _freq;
         }
 
@@ -94,9 +98,11 @@ namespace dsp {
             _CorrectedFallRate = _fallRate / _sampleRate;
             generic_block<AGC>::registerInput(_in);
             generic_block<AGC>::registerOutput(&out);
+            generic_block<AGC>::_block_init = true;
         }
 
         void setInput(stream<float>* in) {
+            assert(generic_block<AGC>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<AGC>::ctrlMtx);
             generic_block<AGC>::tempStop();
             generic_block<AGC>::unregisterInput(_in);
@@ -106,12 +112,14 @@ namespace dsp {
         }
 
         void setSampleRate(float sampleRate) {
+            assert(generic_block<AGC>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<AGC>::ctrlMtx);
             _sampleRate = sampleRate;
             _CorrectedFallRate = _fallRate / _sampleRate;
         }
 
         void setFallRate(float fallRate) {
+            assert(generic_block<AGC>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<AGC>::ctrlMtx);
             _fallRate = fallRate;
             _CorrectedFallRate = _fallRate / _sampleRate;
@@ -160,9 +168,11 @@ namespace dsp {
             _rate = rate;
             generic_block<ComplexAGC>::registerInput(_in);
             generic_block<ComplexAGC>::registerOutput(&out);
+            generic_block<ComplexAGC>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<ComplexAGC>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<ComplexAGC>::ctrlMtx);
             generic_block<ComplexAGC>::tempStop();
             generic_block<ComplexAGC>::unregisterInput(_in);
@@ -172,14 +182,17 @@ namespace dsp {
         }
 
         void setSetPoint(float setPoint) {
+            assert(generic_block<ComplexAGC>::_block_init);
             _setPoint = setPoint;
         }
 
         void setMaxGain(float maxGain) {
+            assert(generic_block<ComplexAGC>::_block_init);
             _maxGain = maxGain;
         }
 
         void setRate(float rate) {
+            assert(generic_block<ComplexAGC>::_block_init);
             _rate = rate;
         }
 
@@ -222,9 +235,11 @@ namespace dsp {
             _in = in;
             generic_block<DelayImag>::registerInput(_in);
             generic_block<DelayImag>::registerOutput(&out);
+            generic_block<DelayImag>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<DelayImag>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<DelayImag>::ctrlMtx);
             generic_block<DelayImag>::tempStop();
             generic_block<DelayImag>::unregisterInput(_in);
@@ -272,9 +287,11 @@ namespace dsp {
             _volume = volume;
             generic_block<Volume<T>>::registerInput(_in);
             generic_block<Volume<T>>::registerOutput(&out);
+            generic_block<Volume<T>>::_block_init = true;
         }
 
-        void setInputSize(stream<T>* in) {
+        void setInput(stream<T>* in) {
+            assert(generic_block<Volume<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Volume<T>>::ctrlMtx);
             generic_block<Volume<T>>::tempStop();
             generic_block<Volume<T>>::unregisterInput(_in);
@@ -284,19 +301,23 @@ namespace dsp {
         }
 
         void setVolume(float volume) {
+            assert(generic_block<Volume<T>>::_block_init);
             _volume = volume;
             level = powf(_volume, 2);
         }
 
         float getVolume() {
+            assert(generic_block<Volume<T>>::_block_init);
             return _volume;
         }
 
         void setMuted(bool muted) {
+            assert(generic_block<Volume<T>>::_block_init);
             _muted = muted;
         }
 
         bool getMuted() {
+            assert(generic_block<Volume<T>>::_block_init);
             return _muted;
         }
 
@@ -343,8 +364,10 @@ namespace dsp {
         Squelch(stream<complex_t>* in, float level) { init(in, level); }
 
         ~Squelch() {
+            if (!generic_block<Squelch>::_block_init) { return; }
             generic_block<Squelch>::stop();
             delete[] normBuffer;
+            generic_block<Squelch>::_block_init = false;
         }
 
         void init(stream<complex_t>* in, float level) {
@@ -353,9 +376,11 @@ namespace dsp {
             normBuffer = new float[STREAM_BUFFER_SIZE];
             generic_block<Squelch>::registerInput(_in);
             generic_block<Squelch>::registerOutput(&out);
+            generic_block<Squelch>::_block_init = true;
         }
 
         void setInput(stream<complex_t>* in) {
+            assert(generic_block<Squelch>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Squelch>::ctrlMtx);
             generic_block<Squelch>::tempStop();
             generic_block<Squelch>::unregisterInput(_in);
@@ -365,10 +390,12 @@ namespace dsp {
         }
 
         void setLevel(float level) {
+            assert(generic_block<Squelch>::_block_init);
             _level = level;
         }
 
         float getLevel() {
+            assert(generic_block<Squelch>::_block_init);
             return _level;
         }
 
@@ -415,9 +442,11 @@ namespace dsp {
             samples = count;
             generic_block<Packer<T>>::registerInput(_in);
             generic_block<Packer<T>>::registerOutput(&out);
+            generic_block<Packer<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<Packer<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Packer<T>>::ctrlMtx);
             generic_block<Packer<T>>::tempStop();
             generic_block<Packer<T>>::unregisterInput(_in);
@@ -427,6 +456,7 @@ namespace dsp {
         }
 
         void setSampleCount(int count) {
+            assert(generic_block<Packer<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Packer<T>>::ctrlMtx);
             generic_block<Packer<T>>::tempStop();
             samples = count;
@@ -473,8 +503,10 @@ namespace dsp {
         Threshold(stream<float>* in) { init(in); }
 
         ~Threshold() {
+            if (!generic_block<Threshold>::_block_init) { return; }
             generic_block<Threshold>::stop();
             delete[] normBuffer;
+            generic_block<Threshold>::_block_init = false;
         }
 
         void init(stream<float>* in) {
@@ -482,9 +514,11 @@ namespace dsp {
             normBuffer = new float[STREAM_BUFFER_SIZE];
             generic_block<Threshold>::registerInput(_in);
             generic_block<Threshold>::registerOutput(&out);
+            generic_block<Threshold>::_block_init = true;
         }
 
         void setInput(stream<float>* in) {
+            assert(generic_block<Threshold>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Threshold>::ctrlMtx);
             generic_block<Threshold>::tempStop();
             generic_block<Threshold>::unregisterInput(_in);
@@ -494,10 +528,12 @@ namespace dsp {
         }
 
         void setLevel(float level) {
+            assert(generic_block<Threshold>::_block_init);
             _level = level;
         }
 
         float getLevel() {
+            assert(generic_block<Threshold>::_block_init);
             return _level;
         }
 
diff --git a/core/src/dsp/resampling.h b/core/src/dsp/resampling.h
index bd761e6c..bf8edc24 100644
--- a/core/src/dsp/resampling.h
+++ b/core/src/dsp/resampling.h
@@ -14,10 +14,12 @@ namespace dsp {
         PolyphaseResampler(stream<T>* in, dsp::filter_window::generic_window* window, float inSampleRate, float outSampleRate) { init(in, window, inSampleRate, outSampleRate); }
 
         ~PolyphaseResampler() {
+            if (!generic_block<PolyphaseResampler<T>>::_block_init) { return; }
             generic_block<PolyphaseResampler<T>>::stop();
             volk_free(buffer);
             volk_free(taps);
             freeTapPhases();
+            generic_block<PolyphaseResampler<T>>::_block_init = false;
         }
 
         void init(stream<T>* in, dsp::filter_window::generic_window* window, float inSampleRate, float outSampleRate) {
@@ -40,9 +42,11 @@ namespace dsp {
             memset(buffer, 0, STREAM_BUFFER_SIZE * sizeof(T) * 2);
             generic_block<PolyphaseResampler<T>>::registerInput(_in);
             generic_block<PolyphaseResampler<T>>::registerOutput(&out);
+            generic_block<PolyphaseResampler<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<PolyphaseResampler<T>>::ctrlMtx);
             generic_block<PolyphaseResampler<T>>::tempStop();
             generic_block<PolyphaseResampler<T>>::unregisterInput(_in);
@@ -52,6 +56,7 @@ namespace dsp {
         }
 
         void setInSampleRate(float inSampleRate) {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<PolyphaseResampler<T>>::ctrlMtx);
             generic_block<PolyphaseResampler<T>>::tempStop();
             _inSampleRate = inSampleRate;
@@ -63,6 +68,7 @@ namespace dsp {
         }
 
         void setOutSampleRate(float outSampleRate) {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<PolyphaseResampler<T>>::ctrlMtx);
             generic_block<PolyphaseResampler<T>>::tempStop();
             _outSampleRate = outSampleRate;
@@ -74,14 +80,17 @@ namespace dsp {
         }
 
         int getInterpolation() {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             return _interp;
         }
 
         int getDecimation() {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             return _decim;
         }
 
         void updateWindow(dsp::filter_window::generic_window* window) {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<PolyphaseResampler<T>>::ctrlMtx);
             generic_block<PolyphaseResampler<T>>::tempStop();
             _window = window;
@@ -94,6 +103,7 @@ namespace dsp {
         }
 
         int calcOutSize(int in) {
+            assert(generic_block<PolyphaseResampler<T>>::_block_init);
             return (in * _interp) / _decim;
         }
 
@@ -187,87 +197,4 @@ namespace dsp {
         std::vector<float*> tapPhases;
 
     };
-
-    class PowerDecimator : public generic_block<PowerDecimator> {
-    public:
-        PowerDecimator() {}
-
-        PowerDecimator(stream<complex_t>* in, int power, int tapCount) { init(in, power, tapCount); }
-
-        void init(stream<complex_t>* in, int power, int tapCount) {
-            _in = in;
-            _power = power;
-            _tapCount = tapCount;
-
-            // Allocate buffers
-            for (int i = 0; i < _power; i++) {
-                buffers[i] = new complex_t[STREAM_BUFFER_SIZE / (i+1)];
-                bufferStart[i] = &buffers[i][_tapCount - 1];
-            }
-
-            // Create taps
-            genHalfbandTaps();
-
-            generic_block<PowerDecimator>::registerInput(_in);
-            generic_block<PowerDecimator>::registerOutput(&out);
-        }
-
-        void setInput(stream<complex_t>* in) {
-            std::lock_guard<std::mutex> lck(generic_block<PowerDecimator>::ctrlMtx);
-            generic_block<PowerDecimator>::tempStop();
-            generic_block<PowerDecimator>::unregisterInput(_in);
-            _in = in;
-            generic_block<PowerDecimator>::registerInput(_in);
-            generic_block<PowerDecimator>::tempStart();
-        }
-
-        void setPower(unsigned int power) {
-            std::lock_guard<std::mutex> lck(generic_block<PowerDecimator>::ctrlMtx);
-            generic_block<PowerDecimator>::tempStop();
-            _power = power;
-            generic_block<PowerDecimator>::tempStart();
-        }
-
-        int run() {
-            int count = _in->read();
-            if (count < 0) { return -1; }
-            
-            if (!out.swap(count)) { return -1; }
-            return count; 
-        }
-
-        stream<complex_t> out;
-
-    private:
-        void genHalfbandTaps() {
-            if (taps != NULL) { delete[] taps; }
-            taps = new float[_tapCount];
-
-            // Using Blackman-harris windows
-            int half = _tapCount / 2;
-            for (int i = 0; i < _tapCount; i++) {
-                taps[i] = sinc((FL_M_PI / 2.0f) * (i-half)) * blackmanHarrisWin(i, _tapCount - 1);
-                printf("%f\n", taps[i]);
-            }
-        }
-
-        inline float sinc(float x) {
-            return ((x == 0) ? 1.0f : (sinf(x)/x)) / FL_M_PI;
-        }
-
-        inline float blackmanHarrisWin(float n, float N) {
-            return 0.35875f - (0.48829f*cosf(2.0f*FL_M_PI*(n/N))) + (0.14128f*cosf(4.0f*FL_M_PI*(n/N))) - (0.01168f*cosf(6.0f*FL_M_PI*(n/N)));
-        }
-
-        int _power = 0;
-        int _tapCount = 31;
-        stream<complex_t>* _in;
-
-        // Buffer lists, sets max decimation to 2^32
-        complex_t* buffers[32];
-        complex_t* bufferStart[32];
-
-        float* taps = NULL;
-
-    };
 }
\ No newline at end of file
diff --git a/core/src/dsp/routing.h b/core/src/dsp/routing.h
index 8d8f5fad..3e57160b 100644
--- a/core/src/dsp/routing.h
+++ b/core/src/dsp/routing.h
@@ -16,9 +16,11 @@ namespace dsp {
         void init(stream<T>* in) {
             _in = in;
             generic_block<Splitter>::registerInput(_in);
+            generic_block<Splitter>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<Splitter>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Splitter>::ctrlMtx);
             generic_block<Splitter>::tempStop();
             generic_block<Splitter>::unregisterInput(_in);
@@ -28,6 +30,7 @@ namespace dsp {
         }
 
         void bindStream(stream<T>* stream) {
+            assert(generic_block<Splitter>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Splitter>::ctrlMtx);
             generic_block<Splitter>::tempStop();
             out.push_back(stream);
@@ -36,6 +39,7 @@ namespace dsp {
         }
 
         void unbindStream(stream<T>* stream) {
+            assert(generic_block<Splitter>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Splitter>::ctrlMtx);
             generic_block<Splitter>::tempStop();
             generic_block<Splitter>::unregisterOutput(stream);
@@ -71,6 +75,7 @@ namespace dsp {
         Reshaper(stream<T>* in, int keep, int skip) { init(in, keep, skip); }
 
         // NOTE: For some reason, the base class destrcutor doesn't get called.... this is a temporary fix I guess
+        // I also don't check for _block_init for the exact sample reason, something's weird
         ~Reshaper() {
             generic_block<Reshaper<T>>::stop();
         }
@@ -82,9 +87,11 @@ namespace dsp {
             ringBuf.init(keep * 2);
             generic_block<Reshaper<T>>::registerInput(_in);
             generic_block<Reshaper<T>>::registerOutput(&out);
+            generic_block<Reshaper<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<Reshaper<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Reshaper<T>>::ctrlMtx);
             generic_block<Reshaper<T>>::tempStop();
             generic_block<Reshaper<T>>::unregisterInput(_in);
@@ -94,6 +101,7 @@ namespace dsp {
         }
 
         void setKeep(int keep) {
+            assert(generic_block<Reshaper<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Reshaper<T>>::ctrlMtx);
             generic_block<Reshaper<T>>::tempStop();
             _keep = keep;
@@ -102,6 +110,7 @@ namespace dsp {
         }
 
         void setSkip(int skip) {
+            assert(generic_block<Reshaper<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<Reshaper<T>>::ctrlMtx);
             generic_block<Reshaper<T>>::tempStop();
             _skip = skip;
@@ -182,7 +191,6 @@ namespace dsp {
         std::thread bufferWorkerThread;
         std::thread workThread;
         int _keep, _skip;
-        
 
     };
 }
\ No newline at end of file
diff --git a/core/src/dsp/sink.h b/core/src/dsp/sink.h
index 97299dc6..cb97402a 100644
--- a/core/src/dsp/sink.h
+++ b/core/src/dsp/sink.h
@@ -16,9 +16,11 @@ namespace dsp {
             _handler = handler;
             _ctx = ctx;
             generic_block<HandlerSink<T>>::registerInput(_in);
+            generic_block<HandlerSink<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<HandlerSink<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<HandlerSink<T>>::ctrlMtx);
             generic_block<HandlerSink<T>>::tempStop();
             generic_block<HandlerSink<T>>::unregisterInput(_in);
@@ -28,6 +30,7 @@ namespace dsp {
         }
 
         void setHandler(void (*handler)(T* data, int count, void* ctx), void* ctx) {
+            assert(generic_block<HandlerSink<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<HandlerSink<T>>::ctrlMtx);
             generic_block<HandlerSink<T>>::tempStop();
             _handler = handler;
@@ -61,9 +64,11 @@ namespace dsp {
             _in = in;
             data.init(480); // TODO: Use an argument
             generic_block<RingBufferSink<T>>::registerInput(_in);
+            generic_block<RingBufferSink<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<RingBufferSink<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<RingBufferSink<T>>::ctrlMtx);
             generic_block<RingBufferSink<T>>::tempStop();
             generic_block<RingBufferSink<T>>::unregisterInput(_in);
@@ -107,9 +112,11 @@ namespace dsp {
         void init(stream<T>* in) {
             _in = in;
             generic_block<NullSink<T>>::registerInput(_in);
+            generic_block<NullSink<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<NullSink<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<NullSink<T>>::ctrlMtx);
             generic_block<NullSink<T>>::tempStop();
             generic_block<NullSink<T>>::unregisterInput(_in);
@@ -138,17 +145,21 @@ namespace dsp {
         FileSink(stream<T>* in, std::string path) { init(in, path); }
 
         ~FileSink() {
+            if (!generic_block<FileSink<T>>::_block_init) { return; }
             generic_block<FileSink<T>>::stop();
             if (file.is_open()) { file.close(); }
+            generic_block<FileSink<T>>::_block_init = false;
         }
 
         void init(stream<T>* in, std::string path) {
             _in = in;
             file = std::ofstream(path, std::ios::binary);
             generic_block<FileSink<T>>::registerInput(_in);
+            generic_block<FileSink<T>>::_block_init = true;
         }
 
         void setInput(stream<T>* in) {
+            assert(generic_block<FileSink<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<FileSink<T>>::ctrlMtx);
             generic_block<FileSink<T>>::tempStop();
             generic_block<FileSink<T>>::unregisterInput(_in);
@@ -158,6 +169,7 @@ namespace dsp {
         }
 
         bool isOpen() {
+            assert(generic_block<FileSink<T>>::_block_init);
             return file.is_open();
         }
 
diff --git a/core/src/dsp/source.h b/core/src/dsp/source.h
index 78c2d2ac..535544d3 100644
--- a/core/src/dsp/source.h
+++ b/core/src/dsp/source.h
@@ -20,9 +20,11 @@ namespace dsp {
             phase = lv_cmake(1.0f, 0.0f);
             phaseDelta = lv_cmake(std::cos((_freq / _sampleRate) * 2.0f * FL_M_PI), std::sin((_freq / _sampleRate) * 2.0f * FL_M_PI));
             generic_block<SineSource>::registerOutput(&out);
+            generic_block<SineSource>::_block_init = true;
         }
 
         void setBlockSize(int blockSize) {
+            assert(generic_block<SineSource>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<SineSource>::ctrlMtx);
             generic_block<SineSource>::tempStop();
             _blockSize = blockSize;
@@ -30,26 +32,29 @@ namespace dsp {
         }
 
         int getBlockSize() {
+            assert(generic_block<SineSource>::_block_init);
             return _blockSize;
         }
 
         void setSampleRate(float sampleRate) {
-            // No need to restart
+            assert(generic_block<SineSource>::_block_init);
             _sampleRate = sampleRate;
             phaseDelta = lv_cmake(std::cos((_freq / _sampleRate) * 2.0f * FL_M_PI), std::sin((_freq / _sampleRate) * 2.0f * FL_M_PI));
         }
 
         float getSampleRate() {
+            assert(generic_block<SineSource>::_block_init);
             return _sampleRate;
         }
 
         void setFrequency(float freq) {
-            // No need to restart
+            assert(generic_block<SineSource>::_block_init);
             _freq = freq;
             phaseDelta = lv_cmake(std::cos((_freq / _sampleRate) * 2.0f * FL_M_PI), std::sin((_freq / _sampleRate) * 2.0f * FL_M_PI));
         }
 
         float getFrequency() {
+            assert(generic_block<SineSource>::_block_init);
             return _freq;
         }
 
@@ -82,9 +87,11 @@ namespace dsp {
             _handler = handler;
             _ctx = ctx;
             generic_block<HandlerSource<T>>::registerOutput(&out);
+            generic_block<HandlerSource<T>>::_block_init = true;
         }
 
         void setHandler(int (*handler)(T* data, void* ctx), void* ctx) {
+            assert(generic_block<HandlerSource<T>>::_block_init);
             std::lock_guard<std::mutex> lck(generic_block<HandlerSource<T>>::ctrlMtx);
             generic_block<HandlerSource<T>>::tempStop();
             _handler = handler;
diff --git a/core/src/dsp/vfo.h b/core/src/dsp/vfo.h
index 251bc3d9..4edb56bd 100644
--- a/core/src/dsp/vfo.h
+++ b/core/src/dsp/vfo.h
@@ -10,7 +10,11 @@ namespace dsp {
     public:
         VFO() {}
 
-        ~VFO() { stop(); }
+        ~VFO() {
+            if (!_init) { return; }
+            stop();
+            _init = false;
+        }
 
         VFO(stream<complex_t>* in, float offset, float inSampleRate, float outSampleRate, float bandWidth) {
             init(in, offset, inSampleRate, outSampleRate, bandWidth);
@@ -33,21 +37,26 @@ namespace dsp {
             resamp.updateWindow(&win);
 
             out = &resamp.out;
+
+            _init = true;
         }
 
         void start() {
+            assert(_init);
             if (running) { return; }
             xlator.start();
             resamp.start();
         }
 
         void stop() {
+            assert(_init);
             if (!running) { return; }
             xlator.stop();
             resamp.stop();
         }
 
         void setInSampleRate(float inSampleRate) {
+            assert(_init);
             _inSampleRate = inSampleRate;
             if (running) { xlator.stop(); resamp.stop(); }
             xlator.setSampleRate(_inSampleRate);
@@ -61,6 +70,7 @@ namespace dsp {
         }
 
         void setOutSampleRate(float outSampleRate) {
+            assert(_init);
             _outSampleRate = outSampleRate;
             if (running) { resamp.stop(); }
             resamp.setOutSampleRate(_outSampleRate);
@@ -73,6 +83,7 @@ namespace dsp {
         }
 
         void setOutSampleRate(float outSampleRate, float bandWidth) {
+            assert(_init);
             _outSampleRate = outSampleRate;
             _bandWidth = bandWidth;
             if (running) { resamp.stop(); }
@@ -86,11 +97,13 @@ namespace dsp {
         }
 
         void setOffset(float offset) {
+            assert(_init);
             _offset = offset;
             xlator.setFrequency(-_offset);
         }
 
         void setBandwidth(float bandWidth) {
+            assert(_init);
             _bandWidth = bandWidth;
             float realCutoff = std::min<float>(_bandWidth, std::min<float>(_inSampleRate, _outSampleRate)) / 2.0f;
             win.setCutoff(realCutoff);
@@ -101,6 +114,7 @@ namespace dsp {
         stream<complex_t>* out;
 
     private:
+        bool _init = false;
         bool running = false;
         float _offset, _inSampleRate, _outSampleRate, _bandWidth;
         filter_window::BlackmanWindow win;
diff --git a/recorder/src/main.cpp b/recorder/src/main.cpp
index ecc55472..873e7c36 100644
--- a/recorder/src/main.cpp
+++ b/recorder/src/main.cpp
@@ -159,7 +159,7 @@ private:
         audioInput = sigpath::sinkManager.bindStream(name);
         if (audioInput == NULL) { return; }
         selectedStreamName = name;
-        vol.setInputSize(audioInput);
+        vol.setInput(audioInput);
         vol.start();
     }