Scarlett 2i2 and Solo

Talk about your MIDI interfaces, microphones, keyboards...

Moderators: khz, MattKingUSA

Soulhar
Posts: 1
Joined: Fri Aug 30, 2019 12:14 am

Scarlett 2i2 and Solo

Postby Soulhar » Fri Aug 30, 2019 12:19 am

Have a 2i2 and solo, both second gen and would like to get these up and running together. I have been able to get ONE running but not both. Just did a fresh install of AVLinux and this is where i am at. Followed all kinds of youtube videos and tutorials and nothing i have done can get qjack to connect to both. Any help would be AWESOME!!!

User avatar
bluebell
Established Member
Posts: 1149
Joined: Sat Sep 15, 2012 11:44 am
Location: Saarland & Frankfurt, Germany

Re: Scarlett 2i2 and Solo

Postby bluebell » Fri Aug 30, 2019 8:23 am

Soulhar wrote:Have a 2i2 and solo, both second gen and would like to get these up and running together. I have been able to get ONE running but not both. Just did a fresh install of AVLinux and this is where i am at. Followed all kinds of youtube videos and tutorials and nothing i have done can get qjack to connect to both. Any help would be AWESOME!!!


Multiple interface have to be hardware-synced. The Scarletts have no external sync connectors. You won't get high quality results.

http://www.jackaudio.org/faq/multiple_devices.html

I gave up and got me an interface with more outputs.

Why do you want to couple them?
Last edited by bluebell on Fri Aug 30, 2019 9:31 am, edited 1 time in total.
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

User avatar
Fmajor7add9
Established Member
Posts: 52
Joined: Sun Dec 31, 2017 3:56 am
Location: Might be moving to Montana soon
Contact:

Re: Scarlett 2i2 and Solo

Postby Fmajor7add9 » Fri Aug 30, 2019 9:03 am

Soulhar wrote:Have a 2i2 and solo, both second gen and would like to get these up and running together. I have been able to get ONE running but not both. Just did a fresh install of AVLinux and this is where i am at. Followed all kinds of youtube videos and tutorials and nothing i have done can get qjack to connect to both. Any help would be AWESOME!!!


Hi from another newbie signing up to your OP and also curious on how to run multiple soundcards with Jack. AFAIK (not much yet) Jack can only have one soundcard as either input or output (p.81 in AVL2019UserManual.pdf).

Question is if any jack aware applications could provide a bridge to other soundcards, Carla f.ex, like there is a PulseAudio bridge (or sink) to and from Jack. Pulse then uses the 2nd soundcard as default. If not, then maybe on ALSA level some kind of dummy or umbrella virtual soundcard that can catch all devices before opening them to jack...

Also curious how it can be solved if you want outputs from both soundcards, to two set of speakers or external hardware or whatever.

I did it on bloody Windows 7 once, with ASIO4ALL and http://sar.audio, connecting PCI, one Firewire and two USB devices.

User avatar
Fmajor7add9
Established Member
Posts: 52
Joined: Sun Dec 31, 2017 3:56 am
Location: Might be moving to Montana soon
Contact:

Re: Scarlett 2i2 and Solo

Postby Fmajor7add9 » Fri Aug 30, 2019 9:13 am

bluebell wrote:
Soulhar wrote:Multiple interface have to be hardware-synced. The Scarlett's have no external sync connectors. You won't get high quality results.

http://www.jackaudio.org/faq/multiple_devices.html


Seems promising:

1. Use the alsa_in and alsa_out clients (Linux & ALSA only)

If you are using JACK on Linux and want to use additional devices that have ALSA driver support (i.e. most PCI, USB and Bluetooth devices), then this is the best option.

alsa_in and alsa_out are two clients written by Torben Hohn that make a single specified ALSA device appear as a set of JACK ports. They both use Erik de Castro Lopo’s libsamplerate library to do any resampling required to keep the audio in sync as the clocks of each device drift over time.


- but doesn't work in your experience? Never knew there was such a thing as hw sync, only thought of it as MIDI time clock/code between sequencers or btw video and audio tracks.

User avatar
bluebell
Established Member
Posts: 1149
Joined: Sat Sep 15, 2012 11:44 am
Location: Saarland & Frankfurt, Germany

Re: Scarlett 2i2 and Solo

Postby bluebell » Fri Aug 30, 2019 9:37 am

Fmajor7add9 wrote:
bluebell wrote:
Soulhar wrote:Multiple interface have to be hardware-synced. The Scarlett's have no external sync connectors. You won't get high quality results.

http://www.jackaudio.org/faq/multiple_devices.html


Seems promising:

1. Use the alsa_in and alsa_out clients (Linux & ALSA only)

If you are using JACK on Linux and want to use additional devices that have ALSA driver support (i.e. most PCI, USB and Bluetooth devices), then this is the best option.

alsa_in and alsa_out are two clients written by Torben Hohn that make a single specified ALSA device appear as a set of JACK ports. They both use Erik de Castro Lopo’s libsamplerate library to do any resampling required to keep the audio in sync as the clocks of each device drift over time.


- but doesn't work in your experience? Never knew there was such a thing as hw sync, only thought of it as MIDI time clock/code between sequencers or btw video and audio tracks.


Some call it "wordclock".

There are many ways to use multiple, unsynced audio adapters, like alsa_in/out, zita-a2j/j2a, jackd's audioadapter and so on. I tried them all and wasn't satisfied with latency and stability.

But of course you can try them. Maybe they suit your needs.

If you need an interface with a low buffer size (low latency, e.g. for guitarix) and an interface with a high buffer size (e.g. for your DAW) then there is a solution that I use: each interface has its own jackd and the guitar interface's audio output goes to the DAW's interface's input.
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

User avatar
Fmajor7add9
Established Member
Posts: 52
Joined: Sun Dec 31, 2017 3:56 am
Location: Might be moving to Montana soon
Contact:

Re: Scarlett 2i2 and Solo

Postby Fmajor7add9 » Fri Aug 30, 2019 10:53 am

bluebell wrote:There are many ways to use multiple, unsynced audio adapters, like alsa_in/out, zita-a2j/j2a, jackd's audioadapter and so on. I tried them all and wasn't satisfied with latency and stability.

But of course you can try them. Maybe they suit your needs.

If you need an interface with a low buffer size (low latency, e.g. for guitarix) and an interface with a high buffer size (e.g. for your DAW) then there is a solution that I use: each interface has its own jackd and the guitar interface's audio output goes to the DAW's interface's input.


Didn't know multiple jackd instances was possible. Do you mind sharing your jack -d commands for them?

Thanks for the other pointers, noted, to be tried.

OT: In your setup does bad stability mean drift, as in 10+ minutes recordings that slowly looses sync?

User avatar
bluebell
Established Member
Posts: 1149
Joined: Sat Sep 15, 2012 11:44 am
Location: Saarland & Frankfurt, Germany

Re: Scarlett 2i2 and Solo

Postby bluebell » Fri Aug 30, 2019 12:39 pm

Fmajor7add9 wrote:
bluebell wrote:There are many ways to use multiple, unsynced audio adapters, like alsa_in/out, zita-a2j/j2a, jackd's audioadapter and so on. I tried them all and wasn't satisfied with latency and stability.

But of course you can try them. Maybe they suit your needs.

If you need an interface with a low buffer size (low latency, e.g. for guitarix) and an interface with a high buffer size (e.g. for your DAW) then there is a solution that I use: each interface has its own jackd and the guitar interface's audio output goes to the DAW's interface's input.


Didn't know multiple jackd instances was possible. Do you mind sharing your jack -d commands for them?

Thanks for the other pointers, noted, to be tried.

OT: In your setup does bad stability mean drift, as in 10+ minutes recordings that slowly looses sync?


I had several experiences as

- crash when starting Audacity (Audacity seems to do some aggressive scans)
- bigger and bigger buffer with more and more latency over time

You can start several jackd if they use a separate interface each and get a unique name (-n ...).

For example I start guitarix with this script:

Code: Select all

#!/bin/bash

FREQ=48000
BUFFERS=3
PERIODSG=16
PRIO=90

for M in 2i2 Solo 2i4
do
  F=`aplay -l | grep $M | cut -d : -f 1 | cut -d " " -f 2`
  if [ -n "$F" ]
  then
    HW="$F"
  fi
done

if [ -n "$HW" ]
then
/usr/bin/jackd -n git -P$PRIO -p512 -t2000 -dalsa \
  -r$FREQ -p$PERIODSG -n$BUFFERS -Xseq -dhw:$HW \
  >/tmp/jackd-hmg.log 2>&1 &

JACKPID=$!
jack_wait -w

sleep 0.5

guitarix -s git
kill -9 $JACKPID
fi
Linux – MOTU UltraLite AVB – Qtractor – https://soundcloud.com/suedwestlicht

User avatar
Michael Willis
Established Member
Posts: 848
Joined: Mon Oct 03, 2016 3:27 pm
Location: Rocky Mountains, North America
Contact:

Re: Scarlett 2i2 and Solo

Postby Michael Willis » Fri Aug 30, 2019 5:42 pm

Ok, somebody has to say it: If you really need that many inputs and/or outputs, it would probably be way less trouble to buy something like the 18i8 or 18i20. Both of which have the added benefit of being expandable via the optical input, which the smaller Scarlett interfaces don't have.


Return to “Computer Related Hardware”

Who is online

Users browsing this forum: No registered users and 2 guests