I'm using the digital optical output on a behringer UCA 202 USB soundcard. Vista works fine to control the volume through the analogue outs but - as I found out when a horribly loud noise came out my speakers - does not control volume through the optical output (which stays at a constant, LOUD, setting). Is this a problem with vista generally, or with the card (this worked fine in XP)? And anyone know a way to fix this?

Running Vista I can control the volume using the optical out.

- check the driver of your soundcard, maybe there is a Vista compatible version
- check the device settings in Vista

Thanks - the device uses the generic USB audio CODEC (which Vista thinks is uptodate), and I don't think Behringer do a PC driver specifically for this card.

Device settings look pretty standard - anything in particular I should keep an eye out for?

I don’t understand,
If this device is using a USB codec, it is using the USB, not the optical out (S/PDIF)

If I use the USB to my USB-DAC, it uses the generic USB audio driver and volume control is enabled
In WMP > Options > Devices , I can configure the output level, balance, etc

Sorry - should have been clearer. I have a USB soundcard running, with both analogue outs and an S/PDIF out. The analogue outs run into an amp, the S/PDIF runs into a DAC.

The Vista volume control works on the analogue outs, but not the S/PDIF...

If I understand correctly
WMP > Volume Control > USB > Behringer
Behringer analogue out has volume control by WMP
Behringer s/pdif not

This is hard to believe except if WMP sees 2 different speakers, 'Behringer analogue' and 'Behringer s/pdif'

You're telling me This is using Vista volume control, rather than WMP (I listen using Foobar), but it is v odd.

Good thought re Vista seeing two different speakers, but it doesn't... Just the USB card, internal card, and HDMI. I'm currently sitting here with Vista's sound muted, while listening to music playing on my computer

Isn't the whole idea of an optical output that you transport the signal untouched? If you lower the volume, you're really applying a DSP, which kinda defeats the purpose of a digital output. I don't know where your optical cable leads to, but if it's an dac then there is where you should turn the volume knob I'd say.

If I open Vista Volume Mixer I see 3 devices
- speaker (USB-DAC)
- Windows sound
- WMP, maybe you see Foobar there

Is Foobar using a special driver bypassing Vista Audio?

I guess you're talking about SPDIF PCM audio. But SPDIF may output passthrough AC3/DTS streams as well and now how should the card control the volume on that?! I guess the volume control is not there for a reason.

Thanks - foobar uses WASAPI. But the same problem effects e.g. youtube videos or bbc radio playing through firefox (or foobar using direct sound). And volume control on all this works from the analogue outputs. I'm kind-of stumped

Martell - do you think this is a deliberate feature, then? Would be odd if it were, as in XP the volume control does control the digital output...

Still stumped Any thoughts as to a possible fix would be great, though appreciate that it's an odd problem...I sometimes think that Vista came with a special curse...

In Vista, digital multimedia handling was changed considerably to prevent raw hi-def data eavesdropping (it's not as easy to tamper with digital data as it was in XP). You will need to get specific drivers that are capable of applying the chosen Windows mixer gain to digital data. Otherwise, you will not be able to affect the volume of embedded (flash) players since you cannot change the way they control audio volume (usually through the Windows mixer, not by directly multiplying the digital waveform which is what you need).
Foobar2000 has direct access to digital data since it produces it so it may apply digital processing at will before it sends the data to the Vista driver.

How would you change output level for digital data? ... Could it be by decreasing data bit depth? 1 bit = ~6dB .. if you have 24-bit data then 8-10 bit decrease wouldn't hurt the quality too much, I guess ...

Juha

Thanks - another reason to dislike attempts at copyright control

Behringer don't seem to do a specific driver for the card (fair enough, I guess - it worked fine with generic USB codec in XP). Any other drivers I could try? I guess there's no way to force audio from flash players etc through foobar?

I think the last thing you asked is mostly nonsense.

Is it that hard to adjust the volume on the external DAC?

There isn't a volume control on the DAC, and I was hoping to run it straight into a power amp. However, this may not be possible.