Kahenraz wrote on 2024-08-28, 03:27:

I bought a bunch of these Chinese knockoff ESS Solo-1s that seemed to work fine in several motherboards but can throw a fit in o […]
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I bought a bunch of these Chinese knockoff ESS Solo-1s that seemed to work fine in several motherboards but can throw a fit in others. For example, I'm trying to slip it into a thin client with a 45 degree angled connector. I thought that it might be small enough to tuck away inside. However, the issue I'm having is that the sound card doesn't work at all in this system. It is detected by the drivers but only emits electrical hums instead of any audible sound.

Why might it be failing to work in my thin client? I tested that both 3.3V and 5V exist on the PCI slot. What else could be missing that is needed on the PCB? I'm curious if it's something that I can retrofit onto it to salvage this project.

I have an ESS Allegro on a similar cut down PCB with the same problem, so it's not limited to just the Solo-1.

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-12V missing ?
PCI Riser Card capacitors - required on all thin clients?

Yes, that seems to be the issue. I confirmed that there is no -12V on the PCI slot. I wonder why the larger version does not have this problem.

Kahenraz wrote on 2024-08-28, 06:03:

I wonder why the larger version does not have this problem.

On the smaller card, there is an op-amp at U4, probably an LM386 or compatible. Pin 4 is the negative voltage input, which is likely connected to pin B1 (component-side, nearest the bracket) which is -12V. The ES1938 and ES1946 datasheets (on page 19 and 22, respectively) have this to say about AOUT_L/R:

...analog outputs AOUT_L and AOUT_R should be AC-coupled to an amplifier, volume control potentiometer, or line-level outputs.

So perhaps you could bypass the op-amp and recreate the same components from the TTSOLO1-S on the smaller card.

The larger version (looks like a Terratec Solo-1) doesn't appear to have an op-amp. There is an optional power-amp that is not fitted, the traces at JP1 for pins 3, 4 appear to go to the filter caps C45, C46? Presumably from there it goes to the AOUT_L/R on the ES1938S. Also trace pins 1, 2 and see what components they go through.

This is the card I have been looking for on AliExpress but they keep on sending Maestro-2SC hahh