[LAU] Sound quality of the Focusrite Scarlett 18i20 2nd Gen

[Johannes Kroll]

On Sun, 8 Jan 2017 21:26:49 +0100
Ralf Mardorf <ralf.mardorf at alice-dsl.net> wrote:

> To patch the kernel, do I need to search an alsa / snd_usb_audio
> source file to add the ID or is it somewhere else? ...

First, look here:
https://github.com/smilingthax/alsa-driver_scarlett/commit/7a77707b66ee476dbf2b87c18fde6a2ea4ded1ec?diff=split
(This patch is now inside the mainline kernel; I did not write it) 

If your second-gen has identical controls to the first-gen 18i20, then
you would have to simply insert your USB ID there and it would just
work. That is, in sound/usb/mixer.c around line 2395, create another
'case' -

case USB_ID(0x1235, 0x8201): /* Focusrite Scarlett 18i20 2nd-gen */

And in sound/usb/scarlettmixer.c after line 1226, insert

case USB_ID(0x1235, 0x8201): info = &s18i20_info; break;

Line numbers might not be 100% identical depending on your kernel
version. 

That should treat your device like a first-gen 18i20, if I
didn't miss anything. No guarantee it will work, but it might.