AMB Laboratories DIY Audio

[rampantandroid]

Hi,

I recently finished my gamma2 build, and took the DAC to work for my workstation - in trying to use it, I discovered that while the gamma2 DAC was able to handle 24bit 192k fine, 24bit 192k on the gamma1 output results in crackling; 24bit 96k however is fine.

On the USB side, the USB Dac will only allow a max of 16bit, 48k...moreover, it would not respond to volume settings - I darn near blew my ear drums out - could this just be a driver issue?

Thanks!
Patrick

[amb]

That's the correct behavior. The sampling rate and bit-depth limitations from the various inputs are documented on the γ1 and γ2 websites.

[rampantandroid]

That's the correct behavior. The sampling rate limitations are documented on the γ1 and γ2 websites.

Ah, I see it now - I had missed the note on it being configured for a lower sampling rate.

Shouldn't the 2707 be working volume wise? Why can I not get the volume to go down, or even mute in windows?

[MisterX]

Because you're using ASIO?

[rampantandroid]

Because you're using ASIO?

I see no options to disable that though in device manager or the sound properties - is this driver specific? Do I somehow need to swap drivers out to get this to change?

I assume I'm using an in box driver from Windows, though the driver has no date or version on it.

[MisterX]

Which version of Windows and which media player are you using?

[linux-works]

Shouldn't the 2707 be working volume wise? Why can I not get the volume to go down, or even mute in windows?

its my understanding that when you have the dac behind the i2s 'curtain', you don't get to see thru to it. or, your computer doesn't.

your computer sees a devices that does not report vol control ability (its job is to send usb data over i2s and so vol control is not really relevant).

if your dac was the 'end point' and not the usb/i2s converter, THEN windows would probably 'see' a vol control *control*.

at least that's how I understand the driver and topology flow.

this is a good thing, though, as you can't accidentally attenuate at digital level. you don't want to.

[rampantandroid]

Shouldn't the 2707 be working volume wise? Why can I not get the volume to go down, or even mute in windows?

its my understanding that when you have the dac behind the i2s 'curtain', you don't get to see thru to it. or, your computer doesn't.

your computer sees a devices that does not report vol control ability (its job is to send usb data over i2s and so vol control is not really relevant).

if your dac was the 'end point' and not the usb/i2s converter, THEN windows would probably 'see' a vol control *control*.

at least that's how I understand the driver and topology flow.

this is a good thing, though, as you can't accidentally attenuate at digital level. you don't want to.

If this is true, then why does the Windows volume affect the coax/toslink connections? Windows APIs allow you to set volume on streams, afaik.

[amb]

Windows volume control works in software, not on the γ1 or γ2 hardware. When you use ASIO or WASAPI, it bypass the Windows internal "kmixer" and you lose the volume control, but it ensures that kmixer won't be mucking with the bits.

As for your question, the reason why the volume control doesn't work over USB, but works over S/PDIF is most likely because the latter is not a "generic" interface. There is a "sound card" behind the S/PDIF port whose driver isn't running via ASIO or WASAPI.

[rampantandroid]

Windows volume control works in software, not on the γ1 or γ2 hardware. When you use ASIO or WASAPI, it bypass the Windows internal "kmixer" and you lose the volume control, but it ensures that kmixer won't be mucking with the bits.

As for your question, the reason why the volume control doesn't work over USB, but works over S/PDIF is most likely because the latter is not a "generic" interface. There is a "sound card" behind the S/PDIF port whose driver isn't running via ASIO or WASAPI.

So what then does it take for the γ1 to allow volume control within windows?