diff --git a/lasp/c/CMakeLists.txt b/lasp/c/CMakeLists.txt
index bf34cea..3551e6b 100644
--- a/lasp/c/CMakeLists.txt
+++ b/lasp/c/CMakeLists.txt
@@ -14,6 +14,7 @@ add_library(lasp_lib
   lasp_aps.c
   lasp_ps.c
   lasp_mq.c
+  lasp_siggen.c
   lasp_worker.c
   lasp_dfifo.c
   lasp_filterbank.c
diff --git a/lasp/c/lasp_assert.h b/lasp/c/lasp_assert.h
index e9584e9..2524c43 100644
--- a/lasp/c/lasp_assert.h
+++ b/lasp/c/lasp_assert.h
@@ -30,6 +30,8 @@ void DBG_AssertFailedExtImplementation(const char* file,
     	DBG_AssertFailedExtImplementation(__FILE__, __LINE__, assert_string );  \
     }
 
+#define assertvalidptr(ptr) dbgassert(ptr,NULLPTRDEREF)
+
 #else // LASP_DEBUG not defined
 
 #define dbgassert(assertion, assert_string)
diff --git a/lasp/c/lasp_siggen.c b/lasp/c/lasp_siggen.c
new file mode 100644
index 0000000..a2e8de1
--- /dev/null
+++ b/lasp/c/lasp_siggen.c
@@ -0,0 +1,141 @@
+// lasp_siggen.c
+//
+// Author: J.A. de Jong -ASCEE
+// 
+// Description:
+// Signal generator implementation
+//////////////////////////////////////////////////////////////////////
+#define TRACERPLUS (-5)
+#include "lasp_alloc.h"
+#include "lasp_assert.h"
+#include "lasp_mat.h"
+
+#define PRIVATE_SIZE 32
+
+typedef enum {
+    SINEWAVE = 0,
+    WHITENOISE,
+    PINKNOISE,
+    SWEEP,
+
+} SignalType;
+
+
+typedef struct {
+    SignalType signaltype;
+    d fs; // Sampling frequency [Hz]
+    void* private;
+
+    char private_data[PRIVATE_SIZE];
+
+} Siggen;
+
+typedef struct { 
+    d curtime;
+    d omg;
+} SinewaveSpecific;
+
+
+Siggen* Siggen_Sinewave_create(const d fs, const d freq) {
+    fsTRACE(15);
+
+    Siggen* sinesiggen = a_malloc(sizeof(Siggen));
+    sinesiggen->signaltype = SINEWAVE;
+    sinesiggen->fs = fs;
+    sinesiggen->private = sinesiggen->private_data;
+    SinewaveSpecific* sp = (SinewaveSpecific*) sinesiggen->private;
+    sp->curtime = 0;
+    sp->omg = 2*number_pi*freq;
+
+    
+    feTRACE(15);
+    return sinesiggen;
+}
+Siggen* Siggen_Whitenoise_create() {
+    fsTRACE(15);
+
+    Siggen* whitenoise = a_malloc(sizeof(Siggen));
+    whitenoise->signaltype = WHITENOISE;
+    
+    feTRACE(15);
+    return whitenoise;
+}
+void Siggen_free(Siggen* siggen) {
+    fsTRACE(15);
+    assertvalidptr(siggen);
+
+    if(siggen->signaltype == SWEEP) {
+        /* Sweep specific stuff here */
+    }
+    
+    a_free(siggen);
+    feTRACE(15);
+}
+static void Sinewave_genSignal(Siggen* siggen, SinewaveSpecific* sine, vd* samples) {
+    fsTRACE(15);
+    assertvalidptr(sine);
+    d ts = 1/siggen->fs;
+    d omg = sine->omg;
+
+    d curtime = sine->curtime;
+    for(us i =0; i< samples->n_rows; i++) {
+        setvecval(samples, i, sin(omg*curtime));
+        curtime = curtime + ts;
+    }
+    sine->curtime = curtime;
+    feTRACE(15);
+}
+
+static d gaussrand() {
+	static d V1, V2, S;
+	static int phase = 0;
+	d X;
+
+	if(phase == 0) {
+		do {
+			d U1 = (d)rand() / RAND_MAX;
+			d U2 = (d)rand() / RAND_MAX;
+
+			V1 = 2 * U1 - 1;
+			V2 = 2 * U2 - 1;
+			S = V1 * V1 + V2 * V2;
+			} while(S >= 1 || S == 0);
+
+		X = V1 * sqrt(-2 * log(S) / S);
+	} else
+		X = V2 * sqrt(-2 * log(S) / S);
+
+	phase = 1 - phase;
+
+	return X;
+}
+static void Whitenoise_genSignal(Siggen* siggen, vd* samples) {
+    for(us i =0; i< samples->n_rows; i++) {
+        d rn = gaussrand();
+        setvecval(samples, i, rn);
+    }
+
+}
+void Siggen_genSignal(Siggen* siggen,vd* samples) {
+    fsTRACE(15);
+    assertvalidptr(siggen);
+    assert_vx(samples);
+    d fs = siggen->fs;
+
+    switch(siggen->signaltype) {
+        case SINEWAVE:
+            Sinewave_genSignal(siggen, (SinewaveSpecific*) siggen->private, 
+                    samples);
+
+            break;
+        case WHITENOISE:
+            Whitenoise_genSignal(siggen, samples);
+
+    }
+     
+    feTRACE(15);
+}
+
+
+
+//////////////////////////////////////////////////////////////////////
diff --git a/lasp/c/lasp_siggen.h b/lasp/c/lasp_siggen.h
new file mode 100644
index 0000000..ab210a8
--- /dev/null
+++ b/lasp/c/lasp_siggen.h
@@ -0,0 +1,57 @@
+// lasp_siggen.h
+//
+// Author: J.A. de Jong - ASCEE
+//
+// Description:
+// Header file for signal generation routines
+//
+//////////////////////////////////////////////////////////////////////
+#pragma once
+#ifndef LASP_SIGGEN_H
+#define LASP_SIGGEN_H
+#include "lasp_mat.h"
+
+typedef struct {} Siggen;
+
+/**
+ * Create a sine wave signal generator
+ * 
+ * @param[in] fs: Sampling frequency [Hz]
+ * @param[freq] Sine wave frequency [Hz]
+ */
+Siggen* Siggen_Sinewave_create(const d fs,const d freq);
+
+/**
+ * Create a white noise signal generator
+ * 
+ * @return Siggen* handle
+ */
+Siggen* Siggen_Whitenoise_create();
+
+/**
+ * Create a pink (1/f) noise signal generator
+ * 
+ * @param[in] fs: Sampling frequency [Hz]
+ * @return Siggen* handle
+ */
+Siggen* Siggen_Pinknoise_create(const us fs);
+
+/* Siggen* Siggen_ForwardSweep_create(const d fs,; */
+/* Siggen* Siggen_(const d fs,; */
+
+/**
+ * Obtain a new piece of signal
+ * 
+ * @param[in] Siggen* Signal generator private data
+ * @param[out] samples Samples to fill. Vector should be pre-allocated
+ */
+void Siggen_genSignal(Siggen*,vd* samples);
+/**
+ * Free Siggen data
+ * 
+ * @param[in] Siggen* Signal generator private data
+ */
+void Siggen_free(Siggen*);
+
+#endif LASP_SIGGEN_H
+//////////////////////////////////////////////////////////////////////
diff --git a/lasp/lasp_avstream.py b/lasp/lasp_avstream.py
index 2105655..788ec86 100644
--- a/lasp/lasp_avstream.py
+++ b/lasp/lasp_avstream.py
@@ -65,6 +65,8 @@ class AvStream:
         rtaudio_inputparams = None
         rtaudio_outputparams = None
 
+        self.nframes_per_block = 2048
+
         if self.duplex_mode or avtype == AvType.audio_output:
             rtaudio_outputparams = {'deviceid': device.index,
             # TODO: Add option to specify the number of output channels to use
@@ -92,7 +94,7 @@ class AvStream:
                     rtaudio_inputparams,   # Inputparams
                     self.sampleformat,     # Sampleformat
                     self.samplerate,
-                    2048,                  # Buffer size in frames
+                    self.nframes_per_block, # Buffer size in frames
                     self._audioCallback)
 
         except Exception as e:
diff --git a/lasp/lasp_siggen.py b/lasp/lasp_siggen.py
deleted file mode 100644
index 084d3d4..0000000
--- a/lasp/lasp_siggen.py
+++ /dev/null
@@ -1,86 +0,0 @@
-#!/usr/bin/env python3.6
-# -*- coding: utf-8 -*-
-"""
-Description: Read data from image stream and record sound at the same time
-"""
-from .lasp_atomic import Atomic
-from threading import Thread, Condition, Lock
-from .lasp_avstream import AvType, AvStream
-import numpy as np
-
-class SignalGenerator:
-    """
-    Base class for all signal generator types
-    """
-
-    def __init__(self, stream):
-
-        if not (stream.avtype == AvType.audio_output or (stream.avtype ==
-                                                        AvType.audio_input and
-                                                        stream.duplex_mode)):
-            raise RuntimeError('Invalid stream type. Does not support audio'
-                               'output')
-
-        self.stream = stream
-        self._samplerate = stream.samplerate
-        stream.addCallback(self.streamCallback, AvType.audio_output)
-
-    def stop(self):
-        """
-        Stop generating the signal
-        """
-        self.stream.removeCallback(self.streamCallback, AvType.audio_output)
-
-    def streamCallback(self, indata, outdata, blockctr):
-        """
-        Callback from AvStream.
-        """
-        signal = self.getSignal(blockctr*outdata.shape[0], outdata.shape[0])
-        dtype = self.stream.numpy_dtype
-
-        if dtype == np.float32 or dtype == np.float64:
-            fac = 1
-        else:
-            bitdepth_fixed = self.stream.sampwidth*8
-            fac = 2**(bitdepth_fixed-1)
-
-        outdata[:, :] = (fac*signal).astype(dtype)[:, np.newaxis]
-
-
-class SineGenerator(SignalGenerator):
-    def __init__(self, stream, freq):
-        self._omg = 2*freq*np.pi
-        super().__init__(stream)
-
-    def getSignal(self, startidx, frames):
-        samplerate = self._samplerate
-        streamtime = startidx/samplerate
-        t = np.linspace(streamtime, streamtime + frames/samplerate, frames)
-
-        return 0.1*np.sin(self._omg*t)
-
-
-class NoiseGenerator(SignalGenerator):
-    def __init__(self, stream, noisetype): 
-        super().__init__(stream)
-    
-    def getSignal(self, startidx, frames):
-        return 0.1*np.random.randn(frames)
-
-class NoiseType:
-    white = (0, 'White noise', )
-    pink = (1, 'Pink noise')
-    types = (white, pink)
-
-    @staticmethod
-    def fillComboBox(combo):
-        for type_ in NoiseType.types:
-            combo.addItem(type_[1])
-
-    @staticmethod
-    def getCurrent(cb):
-        return NoiseType.types[cb.currentIndex()]
-
-
-
-
diff --git a/lasp/wrappers.pyx b/lasp/wrappers.pyx
index 877ec3b..0e2bd42 100644
--- a/lasp/wrappers.pyx
+++ b/lasp/wrappers.pyx
@@ -467,3 +467,54 @@ cdef class SPLowpass:
         vd_free(&input_vd)
 
         return result
+
+
+cdef extern from "lasp_siggen.h":
+    ctypedef struct c_Siggen "Siggen"
+    c_Siggen* Siggen_Whitenoise_create()
+    c_Siggen* Siggen_Sinewave_create(d fs, d freq)
+    void Siggen_genSignal(c_Siggen*, vd* samples) nogil
+    void Siggen_free(c_Siggen*)
+
+
+cdef class Siggen:
+    cdef c_Siggen *_siggen
+
+    def __cinit__(self):
+        self._siggen = NULL
+
+    def __dealloc__(self):
+        if self._siggen:
+            Siggen_free(self._siggen)
+
+    def genSignal(self, us nsamples):
+        output = np.empty(nsamples, dtype=np.float)
+        assert self._siggen != NULL
+
+        cdef d[:] output_view = output
+
+        cdef dmat output_dmat = dmat_foreign_data(nsamples,
+                                                  1,
+                                                  &output_view[0],
+                                                  False)
+        with nogil:
+            Siggen_genSignal(self._siggen,
+                             &output_dmat)
+
+        return output
+
+
+    @staticmethod
+    def sineWave(fs, freq):
+        cdef c_Siggen* c_siggen = Siggen_Sinewave_create(fs, freq)
+        siggen = Siggen()
+        siggen._siggen = c_siggen
+        return siggen
+
+
+    @staticmethod
+    def whiteNoise():
+        cdef c_Siggen* c_siggen = Siggen_Whitenoise_create()
+        siggen = Siggen()
+        siggen._siggen = c_siggen
+        return siggen