diff --git a/lasp/device/lasp_cppuldaq.cpp b/lasp/device/lasp_cppuldaq.cpp
index 35a4a91..d94ba8c 100644
--- a/lasp/device/lasp_cppuldaq.cpp
+++ b/lasp/device/lasp_cppuldaq.cpp
@@ -350,7 +350,7 @@ void threadfcn(DT9837A* td) {
             if(outxstat.currentIndex < buffer_mid_idx_out) {
                 topoutenqueued = false;
                 if(!botoutenqueued) {
-                    cerr << "Copying output buffer to bottom" << endl;
+                    /* cerr << "Copying output buffer to bottom" << endl; */
                     double* bufcpy;
                     if(!outqueue->empty()) {
                         bufcpy = outqueue->dequeue();
@@ -374,7 +374,7 @@ void threadfcn(DT9837A* td) {
                 botoutenqueued = false;
                 if(!topoutenqueued) {
                     topoutenqueued = true;
-                    cerr << "Copying output buffer to top" << endl;
+                    /* cerr << "Copying output buffer to top" << endl; */
                     double* bufcpy;
                     if(!outqueue->empty()) {
                         bufcpy = outqueue->dequeue();
@@ -407,7 +407,7 @@ void threadfcn(DT9837A* td) {
             if(inxstat.currentIndex < buffer_mid_idx_in) {
                 topinenqueued = false;
                 if(!botinenqueued) {
-                    cerr << "Copying in buffer bot" << endl;
+                    /* cerr << "Copying in buffer bot" << endl; */
                     double* bufcpy = static_cast<double*>(malloc(sizeof(double)*samplesPerBlock*neninchannels));
                     us monitoroffset = monitorOutput ? 1: 0;
                     assert(neninchannels > 0);
@@ -448,7 +448,7 @@ void threadfcn(DT9837A* td) {
                         }
                     }
 
-                    cerr << "Copying in buffer top" << endl;
+                    /* cerr << "Copying in buffer top" << endl; */
                     inqueue->enqueue(bufcpy);
                     topinenqueued = true;
                 }
diff --git a/lasp/device/lasp_uldaq.pyx b/lasp/device/lasp_uldaq.pyx
index eb6b5c1..74532e5 100644
--- a/lasp/device/lasp_uldaq.pyx
+++ b/lasp/device/lasp_uldaq.pyx
@@ -11,7 +11,7 @@ DEF UL_ERR_MSG_LEN = 512
 
 ctypedef unsigned us
 
-cdef extern from "lasp_cppdaq.h":
+cdef extern from "lasp_cppdaq.h" nogil:
     cdef cppclass Daq:
         void start(SafeQueue[double*] *inQueue,
                    SafeQueue[double*] *outQueue)
@@ -92,6 +92,7 @@ cdef void audioCallbackPythonThreadFunction(void* voidsd) nogil:
 
         if sd.inQueue: 
             if not sd.outQueue:
+                # Waiting indefinitely on the queue...
                 inbuffer = sd.inQueue.dequeue()
                 if inbuffer == NULL:
                     printf('Stopping thread...\n')
@@ -99,13 +100,14 @@ cdef void audioCallbackPythonThreadFunction(void* voidsd) nogil:
             else:
                 if not sd.inQueue.empty():
                     inbuffer = sd.inQueue.dequeue()
+                    if inbuffer == NULL:
+                        printf('Stopping thread...\n')
+                        return
                 else:
                     inbuffer = NULL
 
         with gil:
             
-            # Obtain stream information
-            npy_input = None
             npy_output = None
             if sd.inQueue and inbuffer:
                 try:
@@ -117,12 +119,22 @@ cdef void audioCallbackPythonThreadFunction(void* voidsd) nogil:
                         True, # Do transfer ownership
                         True) # F-contiguous is True: data is Fortran-cont.
 
+                    rval = callback(npy_input,
+                                    npy_output,
+                                    nFramesPerBlock,
+                                   )
+
                 except Exception as e:
                     print('exception in cython callback for audio input: ', str(e))
                     return
 
+            npy_input = None
             if sd.outQueue: 
                 # fprintf(stderr, 'Copying output buffer to Numpy...\n')
+                rval = callback(npy_input,
+                                npy_output,
+                                nFramesPerBlock,
+                               )
                 try:
                     npy_output = <object> data_to_ndarray(
                         outbuffer,
@@ -136,14 +148,6 @@ cdef void audioCallbackPythonThreadFunction(void* voidsd) nogil:
                     print('exception in Cython callback for audio output: ', str(e))
                     return
 
-            try:
-                rval = callback(npy_input,
-                                npy_output,
-                                nFramesPerBlock,
-                               )
-            except Exception as e:
-                print('Exception in Cython callback: ', str(e))
-                return
 
         if sd.outQueue: 
             sd.outQueue.enqueue(<double*> outbuffer)
@@ -151,7 +155,7 @@ cdef void audioCallbackPythonThreadFunction(void* voidsd) nogil:
                 while sd.outQueue.size() > 10 and not sd.stopThread.load():
                     # printf('Sleeping...\n')
                     # No input queue to wait on, so we relax a bit here.
-                    CPPsleep_ms(1);
+                    CPPsleep_us(10);
 
         # Outputbuffer is free'ed by the audiothread, so should not be touched
         # here.
@@ -160,6 +164,8 @@ cdef void audioCallbackPythonThreadFunction(void* voidsd) nogil:
         # Inputbuffer memory is owned by Numpy, so should not be free'ed
         inbuffer = NULL
 
+    fprintf(stderr, 'Exiting python thread...\n')
+
 cdef class UlDaq:
     cdef:
         PyStreamData *sd
@@ -174,6 +180,15 @@ cdef class UlDaq:
         self.daq_device = NULL
         self.sd = NULL
 
+    def __dealloc__(self):
+        fprintf(stderr, "UlDaq.__dealloc__\n")
+        if self.sd is not NULL:
+            fprintf(stderr, "UlDaq.__dealloc__, stopping stream.\n")
+            self.stop()
+
+    def isRunning(self):
+        return self.sd is not NULL
+
     @cython.nonecheck(True)
     def start(self, avstream):
         """
@@ -258,7 +273,7 @@ cdef class UlDaq:
 
         # Create channel maps for in channels, set in stream
         # parameters
-        inch_enabled = 4*False
+        inch_enabled = 4*[False]
         if in_stream:
             inch_enabled = [True if ch.channel_enabled else False for ch in
                           daqconfig.getInputChannels()]
@@ -266,7 +281,7 @@ cdef class UlDaq:
             self.sd.inQueue = new SafeQueue[double*]()
         
         # Create channel maps for output channels
-        outch_enabled = 4*False
+        outch_enabled = 1*[False]
         if out_stream:
             print('Stream is output stream')
             outch_enabled = [True if ch.channel_enabled else False for ch in
@@ -279,7 +294,7 @@ cdef class UlDaq:
                 daqconfig.nFramesPerBlock,
                 inch_enabled,
                 outch_enabled,
-                daqconfig.samplerate,
+                samplerate,
                 monitorOutput,
                 device.index)
         else:
diff --git a/lasp/device/test_uldaq b/lasp/device/test_uldaq
new file mode 100755
index 0000000..b652c89
Binary files /dev/null and b/lasp/device/test_uldaq differ