On Sat, Mar 7, 2015 at 6:13 PM, Bill White <bill.white@griggsinst.com> wrote:
I apologize in advance for what seems like a trivial and often asked question. But I can't seem to figure out even the tools to diagnose my problem.  I've been reading web pages and alsa and jackd documentation for two weeks, with no luck.

I'm trying to configure my ubuntu 14.04 system to use my Akai EWI USB midi controller. I am trying to use Ted's Linux MIDI Guide to configure things. But before I get midi working I need to test that jackd can route audio to alsa, and I can't get audio ouput from jackd.

I have verified that alsa works with pulseaudio, when pa is running. I disabled pa and then made sure that pa did not autospawn (autospawn = no in /etc/pulseaudio/client.conf.)

I also verified that my hardware device is hw:0. It's the only HW device in my machine. The EWI is not currently plugged in, and it's a MIDI device anyway.

When I run qjackctl and start the server I get this:

19:04:28.770 D-BUS: JACK server was started (org.jackaudio.service aka jackdbus).

Sat Mar 7 19:04:28 2015: Starting jack server...

Sat Mar 7 19:04:28 2015: JACK server starting in realtime mode with priority 10

Sat Mar 7 19:04:28 2015: Acquired audio card Audio0

Sat Mar 7 19:04:28 2015: creating alsa driver ... hw:0|hw:0|128|2|44100|0|0|nomon|swmeter|-|32bit



JACK is using hw:0.

You should check how many channels/ports show up and compare with the number of physical outputs on the audio chipset/back of the computer (and maybe the front too).

 With the Intel HDA in my previous machine (and ONLY that machine), the default outputs when opened by JACK are actually channels 7&8, so to get audio out of them, I had to move the output jack. Open the device a different way (I can't recall the difference) and I would get 8 channels and 1+2 went where expected.

 
P.P.S.  The EWI works with alsa and fluidsynth alone, but there seems to be a noticable latency between fingering notes and hearing the notes.  I'm hoping jack will fix some or all of that.

JACK can't reduce latency. It just tends toward lower latency by default.