Line from Fender AMP not being picked up in Audacity

[dilbot]

Hi there

Using Gentoo Linux w/5.4.38 kernel on Intel.
Audacity 2.2.2 Compiled from code

I'm feeding a USB line in from a Fender Acoustic200 amp. Linux sees the amp OK:

/sys/kernel/debug/usb/devices

T: Bus=01 Lev=02 Prnt=02 Port=01 Cnt=01 Dev#= 3 Spd=12 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1ed8 ProdID=0031 Rev= 1.00
S: Manufacturer=FMIC
S: Product=Fender USB Audio Streaming
S: SerialNumber=FFFFFFFEFFFF
C:* #Ifs= 2 Cfg#= 1 Atr=c0 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 0 Cls=01(audio) Sub=01 Prot=00 Driver=(none)
I:* If#= 1 Alt= 0 #EPs= 0 Cls=01(audio) Sub=02 Prot=00 Driver=(none)
I: If#= 1 Alt= 1 #EPs= 1 Cls=01(audio) Sub=02 Prot=00 Driver=(none)
E: Ad=81(I) Atr=05(Isoc) MxPS= 196 Ivl=1ms

But regardless of using Jack or ALSA, none of the device selections sees the input. I think I've tried every combination there is. This works OK on Win10 with the same line out from the AMP. Any ideas?

[steve]

If you open AlsaMixer and list the sound cards (F6), is the Fender Amp listed?

[dilbot]

Thanks for your reply. Nope, it doesn't come up in AlsaMixer under F6 (Sound Cards) either by itself or with PulseAudio started.

[steve]

Perhaps worth contacting Fender to ask if it is compatible with Linux.

[dilbot]

I talked with Fender Tech on this. They say this should be working OK, since the USB feed is recognized, and since the feed works fine on Windows from the same amp.

It could be a problem with ALSA not picking up the device as a sound card. Strictly speaking, an amp isn't a sound card So maybe it's just not supported at that stage of the process. I'll start checking down that route.

Cheers