Hi,

I have been using jack for years without problems on my debian/stable PC running 4.19.0-17-rt-amd64 #1 SMP PREEMPT RT Debian 4.19.194-3 (2021-07-18) x86_64.

I recently acquired a Boss RC-505 which is giving me trouble getting it's USB audio working. (By contrast I have a Scarlett 2i2 external USB sound card which works 100%)

I use qjackctl to set jack up, and it is giving some error messages which I will include below.

From the perspective of dmesg, lsusb and the info in qjackctl, it looks like the RC-505 is being detected correctly it seems.

FYI when I set up qjackctl to use the RC-505 instead of the Scarlett, I see that jack is set up as follows:

    /usr/bin/jackd -dalsa -r48000 -p256 -n2 -Xseq -D -Chw:RC505 -Phw:PCH

I am a programmer, so I'm not afraid to "get my hands dirty" - I just don't know where to start. What would you guys suggest?

Here's the output from qjackctl:
8<-----------------------------------------------------------------------------------------------------
15:30:24.643 Statistics reset.
15:30:24.645 ALSA connection change.
15:30:24.653 JACK is starting...
15:30:24.653 /usr/bin/jackd -dalsa -r48000 -p256 -n2 -Xseq -D -Chw:RC505 -Phw:PCH
Cannot connect to server socket err = Connection refused
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
Cannot connect to server socket err = Connection refused
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
jackdmp 1.9.12
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2016 Grame.
Copyright 2016-2017 Filipe Coelho.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
audio_reservation_init
Acquire audio card Audio3
Acquire audio card Audio1
creating alsa driver ... hw:PCH|hw:RC505|256|2|48000|0|0|nomon|swmeter|-|32bit
15:30:24.817 ALSA connection graph change.
15:30:24.818 JACK was started with PID=30608.
configuring for 48000Hz, period = 256 frames (5.3 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback
15:30:24.953 ALSA connection graph change.
port created: Midi-Through:midi/playback_1
port created: Midi-Through:midi/capture_1
port created: RC-505:midi/playback_1
port created: RC-505:midi/capture_1
port created: RC-505:midi/playback_2
port created: RC-505:midi/capture_2
15:30:31.868 Could not connect to JACK server as client. - Overall operation failed. - Server communication error. Please check the messages window for more info.
15:30:31.876 Shutdown script...
15:30:31.876 /usr/local/bin/unloop2jack.sh
JackPosixProcessSync::LockedTimedWait error usec = 5000000 err = Connection timed out
Driver is not running
Cannot create new client
Cannot read socket fd = 21 err = Success
CheckRes error
JackSocketClientChannel read fail
Cannot open qjackctl client
JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
Unknown request 4294967295
CheckSize error size = 0 Size() = 12
CheckRead error
JackPosixProcessSync::LockedTimedWait error usec = 5000000 err = Connection timed out
Driver is not running
Cannot create new client
Cannot read socket fd = 5 err = Success
CheckRes error
JackSocketClientChannel read fail
Cannot open jack_disconnect client
JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JACK server not running?
Unknown request 4294967295
CheckSize error size = 0 Size() = 12
CheckRead error
JackPosixProcessSync::LockedTimedWait error usec = 5000000 err = Connection timed out
Driver is not running
Cannot create new client
Cannot read socket fd = 5 err = Success
CheckRes error
JackSocketClientChannel read fail
Cannot open jack_disconnect client
JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JACK server not running?
Unknown request 4294967295
CheckSize error size = 0 Size() = 12
CheckRead error
JackPosixProcessSync::LockedTimedWait error usec = 5000000 err = Connection timed out
Driver is not running
Cannot create new client
Cannot read socket fd = 5 err = Success
CheckRes error
JackSocketClientChannel read fail
Cannot open jack_disconnect client
JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JACK server not running?
Unknown request 4294967295
CheckSize error size = 0 Size() = 12
CheckRead error
JackPosixProcessSync::LockedTimedWait error usec = 5000000 err = Connection timed out
Driver is not running
Cannot create new client
Cannot read socket fd = 5 err = Success
CheckRes error
JackSocketClientChannel read fail
Cannot open jack_disconnect client
JackShmReadWritePtr1::~JackShmReadWritePtr1 - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JACK server not running?
Unknown request 4294967295
CheckSize error size = 0 Size() = 12
CheckRead error
15:30:52.344 Shutdown script terminated successfully.
15:30:52.344 JACK is stopping...
Jack main caught signal 15
8<-----------------------------------------------------------------------------------------------------

Many thanks,
Thomas