diff --git a/src/include/sound.h b/src/include/sound.h
index 402a179d..5c3d2f9d 100644
--- a/src/include/sound.h
+++ b/src/include/sound.h
@@ -100,7 +100,7 @@ public:
 	virtual size_t	Write_stereo(double *, double *, size_t) = 0;
 	virtual size_t	Read(float *, size_t) = 0;
 	virtual void    flush(unsigned dir = UINT_MAX) = 0;
-	virtual bool	must_close(void) = 0;
+	virtual bool	must_close(int dir = 0) = 0;
 #if USE_SNDFILE
 	void		get_file_params(const char* def_fname, const char** fname, int* format);
 	int		Capture(bool val);
@@ -150,7 +150,7 @@ public:
 	size_t		Write(double *, size_t);
 	size_t		Write_stereo(double *, double *, size_t);
 	size_t		Read(float *, size_t);
-	bool		must_close(void) { return true; }
+	bool		must_close(int dir = 0) { return true; }
 	void		flush(unsigned dir = UINT_MAX) { wait_till_finished(); }
 
 private:
@@ -193,13 +193,14 @@ public:
 	size_t 		Write(double *buf, size_t count);
 	size_t		Write_stereo(double *bufleft, double *bufright, size_t count);
 	size_t 		Read(float *buf, size_t count);
-	bool		must_close(void);
+	bool		must_close(int dir = 0);
 	void		flush(unsigned dir = UINT_MAX);
 
 private:
         void		src_data_reset(unsigned dir);
         static long	src_read_cb(void* arg, float** data);
         size_t          resample_write(float* buf, size_t count);
+	device_iterator name_to_device(const std::string& name);
         void 		init_stream(unsigned dir);
         void 		start_stream(unsigned dir);
         void 		pause_stream(unsigned dir);
@@ -276,7 +277,7 @@ public:
 	size_t	Write(double* buf, size_t count);
 	size_t	Write_stereo(double* bufleft, double* bufright, size_t count);
 	size_t	Read(float *buf, size_t count);
-	bool	must_close(void) { return false; }
+	bool	must_close(int dir = 0) { return false; }
 	void	flush(unsigned dir = UINT_MAX);
 
 private:
@@ -323,7 +324,7 @@ public:
 	size_t	Write(double* buf, size_t count);
 	size_t	Write_stereo(double* bufleft, double* bufright, size_t count);
 	size_t	Read(float *buf, size_t count);
-	bool	must_close(void) { return false; }
+	bool	must_close(int dir = 0) { return false; }
 	void	flush(unsigned) { }
 };
 
diff --git a/src/soundcard/sound.cxx b/src/soundcard/sound.cxx
index 9d0ab959..ef0438c0 100644
--- a/src/soundcard/sound.cxx
+++ b/src/soundcard/sound.cxx
@@ -860,7 +860,19 @@ int SoundPort::Open(int mode, int freq)
 	// do we need to (re)initialise the streams?
 	int ret = 0;
 	int sr[2] = { progdefaults.in_sample_rate, progdefaults.out_sample_rate };
-	for (size_t i = 0; i < 2; i++) {
+
+	// initialize stream if it is a JACK device, regardless of mode
+	device_iterator idev;
+	if (mode == O_WRONLY && (idev = name_to_device(sd[0].device)) != devs.end() &&
+	    Pa_GetHostApiInfo((*idev)->hostApi)->type == paJACK)
+		mode = O_RDWR;
+	if (mode == O_RDONLY && (idev = name_to_device(sd[1].device)) != devs.end() &&
+	    Pa_GetHostApiInfo((*idev)->hostApi)->type == paJACK)
+		mode = O_RDWR;
+
+	size_t start = (mode == O_RDONLY || mode == O_RDWR) ? 0 : 1,
+		end = (mode == O_WRONLY || mode == O_RDWR) ? 1 : 0;
+	for (size_t i = start; i <= end; i++) {
 		if ( !(stream_active(i) && (Pa_GetHostApiInfo((*sd[i].idev)->hostApi)->type == paJACK ||
 					    old_sample_rate == freq ||
 					    sr[i] != SAMPLE_RATE_AUTO)) ) {
@@ -1243,6 +1255,15 @@ long SoundPort::src_read_cb(void* arg, float** data)
         return vec[0].len / sd[0].params.channelCount;
 }
 
+SoundPort::device_iterator SoundPort::name_to_device(const string& name)
+{
+	device_iterator i;
+	for (i = devs.begin(); i != devs.end(); ++i)
+		if (name == (*i)->name)
+			break;
+	return i;
+}
+
 void SoundPort::init_stream(unsigned dir)
 {
 	const char* dir_str[2] = { "input", "output" };
@@ -1250,12 +1271,8 @@ void SoundPort::init_stream(unsigned dir)
 
 	LOG_DEBUG("looking for device \"%s\"", sd[dir].device.c_str());
 
-        for (sd[dir].idev = devs.begin(); sd[dir].idev != devs.end(); ++sd[dir].idev) {
-                if (sd[dir].device == (*sd[dir].idev)->name) {
-			idx = sd[dir].idev - devs.begin(); // save this device index
-			break;
-		}
-	}
+	if ((sd[dir].idev = name_to_device(sd[dir].device)) != devs.end())
+		idx = sd[dir].idev - devs.begin();
         if (idx == paNoDevice) { // no match
 		LOG_ERROR("Could not find device \"%s\", using default device", sd[dir].device.c_str());
 		PaDeviceIndex def = (dir == 0 ? Pa_GetDefaultInputDevice() : Pa_GetDefaultOutputDevice());
@@ -1450,9 +1467,9 @@ bool SoundPort::full_duplex_device(const PaDeviceInfo* dev)
         return dev->maxInputChannels > 0 && dev->maxOutputChannels > 0;
 }
 
-bool SoundPort::must_close(void)
+bool SoundPort::must_close(int dir)
 {
-        return false;
+	return Pa_GetHostApiInfo((*sd[dir].idev)->hostApi)->type != paJACK;
 }
 
 // Determine the sample rate that we will use. We try the modem's rate
diff --git a/src/trx/trx.cxx b/src/trx/trx.cxx
index 7a859d96..829bde1a 100644
--- a/src/trx/trx.cxx
+++ b/src/trx/trx.cxx
@@ -170,6 +170,8 @@ void trx_trx_receive_loop()
 			active_modem->HistoryON(false);
 		}
 	}
+	if (scard->must_close(O_RDONLY))
+		scard->Close(O_RDONLY);
 }
 
 
@@ -218,8 +220,9 @@ void trx_trx_transmit_loop()
 			ReedSolomon->send(false);
 
 		scard->flush();
-		if (scard->must_close())
-			scard->Close();
+		if (scard->must_close(O_WRONLY))
+			scard->Close(O_WRONLY);
+
 	} else
 		MilliSleep(10);
 
@@ -269,8 +272,9 @@ void trx_tune_loop()
 			return;
 		}
 		scard->flush();
-		if (scard->must_close())
-			scard->Close();
+		if (scard->must_close(O_WRONLY))
+			scard->Close(O_WRONLY);
+
 		_trx_tune = 0;
 	} else
 		MilliSleep(10);