Crackling noise with USB interface Tascam Model 12 via Linux

[roybatty]

I have been able to connect a Roland MV8800 sampler via ADAT to the Tascam Model 12.

It works like this: two channel adat-out (optical 16bit/44.1kHz) goes to a MCH-streamer (Toslink_only firmware) adat-in. The Tascam Model 12 is via USB connected to a RaspberryPi model4, so is the MCH-streamer. The RaspberryPi is running qjackctl as server. This works flawlessly with a external DAC. There is minimal latency (about 11,6msec). qjackctl runs forced 16bit at 44.1kHz 2 periods and 256 frames. This is the best setting that i have found with no issues.

But when I connect the Tascam Model 12 via USB instead of a DAC random pops / clicks / static / drop-outs appear. Latency settings make no difference.

I have read about using a good USB Super-Speed” A-to-C cable. But switching cables does also seem to make no difference.

(Solved) Tascam Model 12 USB Issues

Hi, I experienced some really odd USB issues with a Tascam Model 12 audio interface. The problem has been resolved, but I am sharing hard-earned info for the next person whom attempts this. First, if attempting to run specialized audio hardware and a Digital Audio Workstation (DAW) software...

forum.maboxlinux.org

There are reports about bugs regarding the Alsa driver. This seems to imply that the current firmware of Tascam Model 12 needs an update.

Intermittent crackling with USB interface Tascam Model 12 (#2009) · Issues · PipeWire / pipewire · GitLab

PipeWire version (pipewire --version): pipewire Compiled with libpipewire...

gitlab.freedesktop.org

Running the Tascam in 24bit/48kHz is not an option because the ADAT data from the Roland is 16bit/44.1kHz.
I could not get this setup working with the Tascam via Windows10 and aiso4all. Which also seems to indicate that there is a bug in the driver/firmware of the Tascam.

I think Tascam should know about this and I wonder if anyone else has come across this issue.

 

[roybatty]

A follow-up in my quest to solve this frustrating problem:

- if you force qjackctl to work in 16bit the connection with the tascam is stable, although an occasion crackling noise will come up, the tascam is set to 44/16; USB3 is mandatory, also use the USB drivers in qjackctl

- if you run qjackctl without "force 16bit" and the tascam in 44/24 the noise is less frequent, but the connection is unstable... the sound just stops, while qjackctl is still running; a restart of qjackctl restores the connection, but this is obviously not a solution

This problem seems to refer to this alsa patch, but I'm not sure:

[PATCH] ALSA: usb-audio: Add quirk for Tascam Model 12

- if you play a 44/16 wav file through wavesauer or audicity to the tascam in 44/16 or 44/24 the same problems appear... running the tascam 48/24 seems fine, but the tascam should be able to play the wav in the original 44/16 format via USB without any problems.

These points confirm my suspicion of a bug in the 44kHz USB mode of the Tascam firmware. In other words: for some reason the Tascam only accepts 48/24 over USB as playback.

 

[roybatty]

I can confirm now that the tascam firmware is the problem: it does not handle 44/16 data well (firmware version 1.42.0099)

My setup can be reproduced, so anyone can hear for themselves what the problem is:

ADAT optical 44/16 -> mch-streamer -> qjackctl -> USB smsl su-1 dac (or any other dac) -> perfect sound

ADAT optical 44/16 -> mch-streamer -> qjackctl -> USB tascam m12 -> not so perfect sound

This had been a frustrating experience, now I'm forced to use a DAC and analogue inputs of the model 12; Tascam should address this problem in a firmware update.