diff --git a/amplitudedemod.cpp b/amplitudedemod.cpp
index f486e82..cdf1267 100644
--- a/amplitudedemod.cpp
+++ b/amplitudedemod.cpp
@@ -19,7 +19,7 @@
 
 #include "amplitudedemod.h"
 
-AmplitudeDemod::AmplitudeDemod(SampleSource<std::complex<float>> *src) : SampleBuffer(src)
+AmplitudeDemod::AmplitudeDemod(std::shared_ptr<SampleSource<std::complex<float>>> src) : SampleBuffer(src)
 {
 
 }
diff --git a/amplitudedemod.h b/amplitudedemod.h
index 4425391..7ce1988 100644
--- a/amplitudedemod.h
+++ b/amplitudedemod.h
@@ -24,6 +24,6 @@
 class AmplitudeDemod : public SampleBuffer<std::complex<float>, float>
 {
 public:
-    AmplitudeDemod(SampleSource<std::complex<float>> *src);
+    AmplitudeDemod(std::shared_ptr<SampleSource<std::complex<float>>> src);
     void work(void *input, void *output, int count, off_t sampleid) override;
 };
diff --git a/frequencydemod.cpp b/frequencydemod.cpp
index bf8b915..c6e5b4d 100644
--- a/frequencydemod.cpp
+++ b/frequencydemod.cpp
@@ -21,7 +21,7 @@
 #include <liquid/liquid.h>
 #include "util.h"
 
-FrequencyDemod::FrequencyDemod(SampleSource<std::complex<float>> *src) : SampleBuffer(src)
+FrequencyDemod::FrequencyDemod(std::shared_ptr<SampleSource<std::complex<float>>> src) : SampleBuffer(src)
 {
 
 }
diff --git a/frequencydemod.h b/frequencydemod.h
index 4242b9c..fb7a016 100644
--- a/frequencydemod.h
+++ b/frequencydemod.h
@@ -24,6 +24,6 @@
 class FrequencyDemod : public SampleBuffer<std::complex<float>, float>
 {
 public:
-    FrequencyDemod(SampleSource<std::complex<float>> *src);
+    FrequencyDemod(std::shared_ptr<SampleSource<std::complex<float>>> src);
     void work(void *input, void *output, int count, off_t sampleid) override;
 };
diff --git a/plots.cpp b/plots.cpp
index 1de2770..9a5070f 100644
--- a/plots.cpp
+++ b/plots.cpp
@@ -34,27 +34,25 @@ Plot* Plots::samplePlot(std::shared_ptr<AbstractSampleSource> source)
 
 Plot* Plots::amplitudePlot(std::shared_ptr<AbstractSampleSource> source)
 {
+    typedef SampleSource<std::complex<float>> ss;
+    std::shared_ptr<ss> cs = std::dynamic_pointer_cast<ss>(source);
     return new TracePlot(
-        std::make_shared<AmplitudeDemod>(
-            std::dynamic_pointer_cast<SampleSource<std::complex<float>>>(source).get()
-        )
+        std::make_shared<AmplitudeDemod>(cs)
     );
 }
 
 Plot* Plots::frequencyPlot(std::shared_ptr<AbstractSampleSource> source)
 {
+    typedef SampleSource<std::complex<float>> ss;
+    std::shared_ptr<ss> cs = std::dynamic_pointer_cast<ss>(source);
     return new TracePlot(
-        std::make_shared<FrequencyDemod>(
-            std::dynamic_pointer_cast<SampleSource<std::complex<float>>>(source).get()
-        )
+        std::make_shared<FrequencyDemod>(cs)
     );
 }
 
 Plot* Plots::thresholdPlot(std::shared_ptr<AbstractSampleSource> source)
 {
-    return new TracePlot(
-        std::make_shared<Threshold>(
-            std::dynamic_pointer_cast<SampleSource<float>>(source).get()
-        )
-    );
-}
\ No newline at end of file
+    typedef SampleSource<float> ss;
+    std::shared_ptr<ss> cs = std::dynamic_pointer_cast<ss>(source);
+    return new TracePlot( std::make_shared<Threshold>( cs ) );
+}
diff --git a/samplebuffer.cpp b/samplebuffer.cpp
index 6135c8e..10bbdb1 100644
--- a/samplebuffer.cpp
+++ b/samplebuffer.cpp
@@ -22,7 +22,7 @@
 #include "samplebuffer.h"
 
 template <typename Tin, typename Tout>
-SampleBuffer<Tin, Tout>::SampleBuffer(SampleSource<Tin> *src) : src(src)
+SampleBuffer<Tin, Tout>::SampleBuffer(std::shared_ptr<SampleSource<Tin>> src) : src(src)
 {
 	src->subscribe(this);
 }
diff --git a/samplebuffer.h b/samplebuffer.h
index 8cb4438..39c93fc 100644
--- a/samplebuffer.h
+++ b/samplebuffer.h
@@ -28,11 +28,11 @@ template <typename Tin, typename Tout>
 class SampleBuffer : public SampleSource<Tout>, public Subscriber
 {
 private:
-    SampleSource<Tin> *src;
+    std::shared_ptr<SampleSource<Tin>> src;
     QMutex mutex;
 
 public:
-    SampleBuffer(SampleSource<Tin> *src);
+    SampleBuffer(std::shared_ptr<SampleSource<Tin>> src);
     ~SampleBuffer();
     void invalidateEvent();
     virtual std::unique_ptr<Tout[]> getSamples(off_t start, off_t length);
diff --git a/spectrogramplot.cpp b/spectrogramplot.cpp
index 90ea391..d7a0f2a 100644
--- a/spectrogramplot.cpp
+++ b/spectrogramplot.cpp
@@ -45,7 +45,7 @@ SpectrogramPlot::SpectrogramPlot(std::shared_ptr<SampleSource<std::complex<float
         colormap[i] = QColor::fromHsvF(p * 0.83f, 1.0, 1.0 - p).rgba();
     }
 
-    tunerTransform = std::make_shared<TunerTransform>(src.get());
+    tunerTransform = std::make_shared<TunerTransform>(src);
     connect(&tuner, &Tuner::tunerMoved, this, &SpectrogramPlot::tunerMoved);
     src->subscribe(this);
 }
diff --git a/threshold.cpp b/threshold.cpp
index dd3b467..7f569db 100644
--- a/threshold.cpp
+++ b/threshold.cpp
@@ -19,7 +19,7 @@
 
 #include "threshold.h"
 
-Threshold::Threshold(SampleSource<float> *src) : SampleBuffer(src)
+Threshold::Threshold(std::shared_ptr<SampleSource<float>> src) : SampleBuffer(src)
 {
 
 }
diff --git a/threshold.h b/threshold.h
index e142cb5..da3b436 100644
--- a/threshold.h
+++ b/threshold.h
@@ -24,6 +24,6 @@
 class Threshold : public SampleBuffer<float, float>
 {
 public:
-    Threshold(SampleSource<float> *src);
+    Threshold(std::shared_ptr<SampleSource<float>> src);
     void work(void *input, void *output, int count, off_t sampleid) override;
 };
diff --git a/tunertransform.cpp b/tunertransform.cpp
index bd12cd3..71325e4 100644
--- a/tunertransform.cpp
+++ b/tunertransform.cpp
@@ -21,7 +21,7 @@
 #include <liquid/liquid.h>
 #include "util.h"
 
-TunerTransform::TunerTransform(SampleSource<std::complex<float>> *src) : SampleBuffer(src), frequency(0), bandwidth(1.), taps{1.0f}
+TunerTransform::TunerTransform(std::shared_ptr<SampleSource<std::complex<float>>> src) : SampleBuffer(src), frequency(0), bandwidth(1.), taps{1.0f}
 {
 
 }
diff --git a/tunertransform.h b/tunertransform.h
index d1520d6..789d7d1 100644
--- a/tunertransform.h
+++ b/tunertransform.h
@@ -30,7 +30,7 @@ private:
     std::vector<float> taps;
 
 public:
-    TunerTransform(SampleSource<std::complex<float>> *src);
+    TunerTransform(std::shared_ptr<SampleSource<std::complex<float>>> src);
     void work(void *input, void *output, int count, off_t sampleid) override;
     void setFrequency(float frequency);
     void setTaps(std::vector<float> taps);