Guitarix amp simulator "Failed to allocate memory" jackd

Has anyone any experience with Guitarix ? I have Jack set up and working well with Rakarrak but it wont work with Guitarix It tells me "could not allocate memory" dont understand why.

Am I missing something ?

Please help...

ulimit -a

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 47217
max locked memory       (kbytes, -l) unlimited
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 95
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 47217
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

This error seems due to pulseaudio and jackd running at the same time.

There are several solutions:

1. Route PulseAudio to Jack while Jack is running
2. Suspend PulseAudio while Jack is running
3. Use two different sound cards
4. Do not use pulseaudio while Jack's running (solution provided in this answer).

To test this, you can suspend pulseaudio while Jackd is running with pasuspender -- jackd or pulseaudio -k.

For a permanent solution we can give jackd real time permissions, by executing the following two commands verbatim:

1. sudo dpkg-reconfigure -p high jackd2 -- Then choose yes, you want to lock down memory and have rtprio scheduling privilege. This will add those lines automatically to config files.
2. sudo usermod -a -G audio $USER or sudo adduser $USER audio -- Add yourself to the audio usergroup
3. Finally, activate the new group by restarting your PC or user session (you can also do it in a single shell with su $USER -c guitarix).