USB guitar cable + Jack on the Pi

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flappix
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USB guitar cable + Jack on the Pi

Post by flappix »

Hi,
I have a cheap USB guitar cable like this one Image
It works very well on my x86 pc and laptop but connected to the Pi, the sound is very weak (low amplitude) and stuttering if I'm using Jackd.
If I only record the sound via arecord (no jack involved), the sound is okay, too.

I've tried a lot of different parameters for jackd, with these ones I get the best result (but even too bad): jackd -r 48000 -n 4 -p 1024

Would be very happy if there are any ideas what I could try to get the cable working with jack :)
Regards,
flappix

asbak
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Re: USB guitar cable + Jack on the Pi

Post by asbak »

Try -n3 -p256 -r48000, however, that cable isn't great.
I couldn't get it (assume yours also uses the cmedia chip?) to work reliably at frames of 256 or less in jack, it would work OK for a while and then start buzzing like mad. I don't think it's worth wasting time on.

Something like an Alesis Guitar Link or Behringer UCG102 should work better but I haven't tested either of them.

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flappix
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Re: USB guitar cable + Jack on the Pi

Post by flappix »

Hi,
thanks for your reply. Unfortunately, these settings are working very bad for me, guitar sounds like a robot.
Yes, I'm using the C-Media chip.
I'm wondering why the device is working well on a non-arm pc (and good enough on arm with pure alsa). So I guess, there have to be an issue with jack?

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flappix
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Re: USB guitar cable + Jack on the Pi

Post by flappix »

I've got a good improvement by self-compiling jack-1.9.8 (used 1.9.10 before) and applying the autostatic patch (little modifications needed).
Quality is not as good as at the pc, but the volume is on a good level now, there are no buzzes and less noise.
All in all quite acceptable.

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flappix
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Re: USB guitar cable + Jack on the Pi

Post by flappix »

The whole problem was caused by the usage of alsa_in.
I now have a simple usb-soundcard (cmedia chip, too) with mic input and speaker output using both as default. Now I get the same clear sound as by the x86 pc with -p 128 -n 3

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