diff --git a/src/main_testtone.cc b/src/main_testtone.cc
index ddf1ea2..0890985 100644
--- a/src/main_testtone.cc
+++ b/src/main_testtone.cc
@@ -1,43 +1,54 @@
-#include "daisy_seed.h"
-#include "daisysp.h"
+#include "types.hh"
 
-namespace ld = daisy;
-namespace dsp = daisysp;
-
-static ld::DaisySeed hardware;
-static dsp::Oscillator osc;
+namespace Heck {
+    namespace Constants {
+    }
 
-void AudioCallback(
-    ld::AudioHandle::InterleavingInputBuffer in,
-    ld::AudioHandle::InterleavingOutputBuffer out,
-    size_t size)
-{
-    float osc_out;
-    osc.SetFreq(1000);
-    for (size_t i = 0; i < size; i += 2) {
-        osc.SetAmp(1.0);
-        osc_out = osc.Process();
-        osc_out *= 0.01;
-        out[i] = osc_out;
-        out[i + 1] = osc_out;
+    ld::DaisySeed hw{};
+    dsp::Oscillator osc{};
+
+    void AudioCallback(
+        ld::AudioHandle::InterleavingInputBuffer in,
+        ld::AudioHandle::InterleavingOutputBuffer out,
+        size_t size)
+    {
+        float osc_out;
+        osc.SetFreq(1000);
+
+        for (size_t i = 0; i < size; i += 2) {
+            osc.SetAmp(1.0);
+            osc_out = osc.Process();
+            osc_out *= 0.005;
+            out[i] = osc_out;
+            out[i + 1] = osc_out;
+        }
     }
-}
 
+    void init()
+    {
+        hw.Configure();
+        hw.Init();
+        hw.SetAudioBlockSize(4);
+        float samplerate = hw.AudioSampleRate();
 
-int main(void)
-{
-    hardware.Configure();
-    hardware.Init();
-    hardware.SetAudioBlockSize(4);
+        osc.Init(samplerate);
+        osc.SetWaveform(osc.WAVE_SIN);
+        osc.SetAmp(1.f);
+        osc.SetFreq(1000);
 
-    float samplerate = hardware.AudioSampleRate();
+        hw.StartAudio(AudioCallback);
+    }
 
-    osc.Init(samplerate);
-    osc.SetWaveform(osc.WAVE_SIN);
-    osc.SetAmp(1.f);
-    osc.SetFreq(1000);
+    void mainloop()
+    {
+        for (;;) {}
+    }
+} // namespace Heck
 
-    hardware.StartAudio(AudioCallback);
 
-    while (true) {}
+int main(void)
+{
+    Heck::init();
+    Heck::mainloop();
+    return 0;
 }
diff --git a/src/types.hh b/src/types.hh
index 2e7f7d0..c459beb 100644
--- a/src/types.hh
+++ b/src/types.hh
@@ -7,7 +7,7 @@
 
 namespace Heck {
 
-    // Types
+    // fundamental types
     using u8 = uint8_t;
     using u16 = uint16_t;
     using u32 = uint32_t;
@@ -24,6 +24,10 @@ namespace Heck {
     // namespace aliases
     namespace ld = daisy;
     namespace dsp = daisysp;
+
+    // type aliases from libs
+    using Samplerate = ld::SaiHandle::Config::SampleRate;
+
 } // namespace Heck