diff --git a/plugins/channeltx/modam/ammod.cpp b/plugins/channeltx/modam/ammod.cpp
index 3d38ae95f..17f91e48b 100644
--- a/plugins/channeltx/modam/ammod.cpp
+++ b/plugins/channeltx/modam/ammod.cpp
@@ -146,7 +146,9 @@ void AMMod::apply()
 	if ((m_config.m_inputFrequencyOffset != m_running.m_inputFrequencyOffset) ||
 	    (m_config.m_outputSampleRate != m_running.m_outputSampleRate))
 	{
+        m_settingsMutex.lock();
 		m_carrierNco.setFreq(m_config.m_inputFrequencyOffset, m_config.m_outputSampleRate);
+        m_settingsMutex.unlock();
 	}
 
 	if((m_config.m_outputSampleRate != m_running.m_outputSampleRate) ||
diff --git a/plugins/samplesink/filesink/filesinkthread.cpp b/plugins/samplesink/filesink/filesinkthread.cpp
index 6c15a0193..983349f9d 100644
--- a/plugins/samplesink/filesink/filesinkthread.cpp
+++ b/plugins/samplesink/filesink/filesinkthread.cpp
@@ -88,6 +88,11 @@ void FileSinkThread::setSamplerate(int samplerate)
 			stopWork();
 		}
 
+		// resize sample FIFO
+		if (m_sampleFifo) {
+		    m_sampleFifo->resize(samplerate, samplerate/4); // 1s buffer with 250ms write chunk size
+		}
+
 		m_samplerate = samplerate;
         m_samplesChunkSize = (m_samplerate * m_throttlems) / 1000;
 	}
diff --git a/plugins/samplesink/filesink/filesinkthread.h b/plugins/samplesink/filesink/filesinkthread.h
index 86bfffd67..2ca252534 100644
--- a/plugins/samplesink/filesink/filesinkthread.h
+++ b/plugins/samplesink/filesink/filesinkthread.h
@@ -57,7 +57,7 @@ private:
 	std::ofstream* m_ofstream;
 	quint8  *m_buf;
 	std::size_t m_bufsize;
-	std::size_t m_samplesChunkSize;
+	unsigned int m_samplesChunkSize;
 	SampleSourceFifo* m_sampleFifo;
     std::size_t m_samplesCount;
 
diff --git a/sdrbase/device/devicesourceapi.cpp b/sdrbase/device/devicesourceapi.cpp
index ef1df5ad6..fbf5c0998 100644
--- a/sdrbase/device/devicesourceapi.cpp
+++ b/sdrbase/device/devicesourceapi.cpp
@@ -332,7 +332,7 @@ void DeviceSourceAPI::loadChannelSettings(const Preset *preset, PluginAPI *plugi
     }
     else
     {
-        qDebug("DeviceSourceAPI::loadChannelSettings: Loading preset [%s | %s] not a source preset\n", qPrintable(preset->getGroup()), qPrintable(preset->getDescription()));
+        qDebug("DeviceSourceAPI::loadChannelSettings: Loading preset [%s | %s] not a source preset", qPrintable(preset->getGroup()), qPrintable(preset->getDescription()));
     }
 }
 
diff --git a/sdrbase/dsp/dspdevicesinkengine.cpp b/sdrbase/dsp/dspdevicesinkengine.cpp
index 0a80efc14..71733fb5e 100644
--- a/sdrbase/dsp/dspdevicesinkengine.cpp
+++ b/sdrbase/dsp/dspdevicesinkengine.cpp
@@ -202,7 +202,6 @@ void DSPDeviceSinkEngine::work()
 			{
 				(*it)->pull(s);
 				s /= (m_threadedBasebandSampleSources.size() + m_basebandSampleSources.size());
-				(*writeAt) += s;
 
                 if (sourceOccurence == 0) {
                     (*writeAt) = s;
diff --git a/sdrbase/dsp/nco.cpp b/sdrbase/dsp/nco.cpp
index 5b0ebb90d..c06c31a53 100644
--- a/sdrbase/dsp/nco.cpp
+++ b/sdrbase/dsp/nco.cpp
@@ -44,7 +44,7 @@ NCO::NCO()
 void NCO::setFreq(Real freq, Real sampleRate)
 {
 	m_phaseIncrement = (freq * TableSize) / sampleRate;
-	qDebug("NCO phase inc %d", m_phaseIncrement);
+	qDebug("NCO freq: %f phase inc %d", freq, m_phaseIncrement);
 }
 
 float NCO::next()
diff --git a/sdrbase/dsp/samplesourcefifo.cpp b/sdrbase/dsp/samplesourcefifo.cpp
index 898f30bb3..d35b3e461 100644
--- a/sdrbase/dsp/samplesourcefifo.cpp
+++ b/sdrbase/dsp/samplesourcefifo.cpp
@@ -31,6 +31,17 @@ SampleSourceFifo::SampleSourceFifo(uint32_t size, uint32_t samplesChunkSize) :
 SampleSourceFifo::~SampleSourceFifo()
 {}
 
+void SampleSourceFifo::resize(uint32_t size, uint32_t samplesChunkSize)
+{
+    qDebug("SampleSourceFifo::resize: %d, %d", size, samplesChunkSize);
+    assert(samplesChunkSize <= size/4);
+
+    m_size = size;
+    m_samplesChunkSize = samplesChunkSize;
+    m_data.resize(2*m_size);
+    init();
+}
+
 void SampleSourceFifo::init()
 {
     memset(&m_data[0], 0, sizeof(2*m_size*sizeof(Sample)));
@@ -84,9 +95,9 @@ void SampleSourceFifo::write(const Sample& sample)
     }
 }
 
-void SampleSourceFifo::getReadIterator(SampleVector::iterator& writeUntil)
+void SampleSourceFifo::getReadIterator(SampleVector::iterator& readUntil)
 {
-	writeUntil = m_data.begin() + m_size + m_ir;
+    readUntil = m_data.begin() + m_size + m_ir;
 }
 
 void SampleSourceFifo::getWriteIterator(SampleVector::iterator& writeAt)
diff --git a/sdrbase/dsp/samplesourcefifo.h b/sdrbase/dsp/samplesourcefifo.h
index aa110e2f6..517b05f81 100644
--- a/sdrbase/dsp/samplesourcefifo.h
+++ b/sdrbase/dsp/samplesourcefifo.h
@@ -33,6 +33,7 @@ public:
 
     unsigned int getChunkSize() const { return m_samplesChunkSize; }
 
+    void resize(uint32_t size, uint32_t samplesChunkSize);
     void init();
     /** begin read at current read point for the given length and activate R/W signals */
     void readAndSignal(SampleVector::iterator& beginRead, unsigned int nbSamples);