In the light of experimentation

Using Zynthian
1

Interesting little attempt of zynthian-amp4.local with a
Guitar to USB lead.

plugged in the new thingie…

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aplay -l
^Croot@zynthian-amp4:~# aplay -l

**** List of PLAYBACK Hardware Devices ****
card 1: b1 [bcm2835 HDMI 1], device 0: bcm2835 HDMI 1 [bcm2835 HDMI 1]
Subdevices: 4/4
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
card 2: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones]
Subdevices: 4/4
Subdevice #0: subdevice #0
Subdevice #1: subdevice #1
Subdevice #2: subdevice #2
Subdevice #3: subdevice #3
card 3: sndrpihifiberry [snd_rpi_hifiberry_dacplus], device 0: HiFiBerry DAC+ HiFi pcm512x-hifi-0 [HiFiBerry DAC+ HiFi pcm512x-hifi-0]
Subdevices: 0/1
Subdevice #0: subdevice #0
card 6: Device [USB Audio Device], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0

Build a new audio effect layer …

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so using alsa_in

alsa_in -j “USBGuitar” -d hw:CARD=Device,DEV=0 -r 44100 -p 256

The new source appears in patchage but un connected …

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so connect it …

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Well it kind of works but not great . . .

amixer -D “hw:CARD=Device” controls
numid=10,iface=CARD,name=‘Keep Interface’
numid=3,iface=MIXER,name=‘Mic Playback Switch’
numid=4,iface=MIXER,name=‘Mic Playback Volume’
numid=7,iface=MIXER,name=‘Mic Capture Switch’
numid=8,iface=MIXER,name=‘Mic Capture Volume’
numid=9,iface=MIXER,name=‘Auto Gain Control’
numid=5,iface=MIXER,name=‘Speaker Playback Switch’
numid=6,iface=MIXER,name=‘Speaker Playback Volume’
numid=2,iface=PCM,name=‘Capture Channel Map’
numid=1,iface=PCM,name=‘Playback Channel Map’

Any thoughts . . .? Presumably we are hearing two slightly different timing clocks at work; the hifiberry and the USB infrastructure clock…?

2

Guitar sound is rather nice, but there’s an horrible background click.

Well, as is, no :expressionless:

You’ve got many sound devices. How do you deal with Jack server ? And how do you record your track (arecord or Zynthian build in recorder ) ?

3

In built zynth recorder.
Thank you, on the guitar tone.
I’ve used alsa_in to define an additional jack source to the running jack instance ( it just runs in a terminal at the moment).

I’m fast running out of USB ports on this machine :smiley:

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4

Try using the guitar USB as the primary and only audio interface to Zythian. alsa_in does samplerate conversion and may not behave brilliantly.

1 Like
5

Yeah, that was what I was thinking about: some kind of “conflict” between alsa “native” interface and jackd layer.

6

Available to Amazon shoppers as well

A cheaper one with USB-C connector

7

In light of @riban suggestion, The Zynth doesn’t seem to like to start up with an audio in only device … So until I’ve fixed tha I wont get to try alsa_out on the hifiberry to see how it goes.