USB digital sound input

eddyad37 · 29 Mar 2010

Note: I've also posted this on the Goldwave Forum in case there is a Goldwave solution.

I've just switched to Windows 7 on a new PC. I own a phono pre-amp with both analogue line and digital USB output.
When I plug the pre-amp into the PC it installs as a "Microphone (USB Audio Codec)". Clicking Record starts at an absurdly high level, almost as if line input was plugged into a mic socket. So the Input Device volume has to be reduced to about 20% to get a sensible recording level.
With my previous PC (Windows XP), Goldwave recognized the USB device as a digital input and (I assume) took the bit stream straight into recording; there was no input volume level available, as I would expect.
But now it looks as if the USB input is being put through the PC sound card, converted to analogue and delivered to Goldwave whereupon it is re-digitized for recording.
If this is so it makes a mockery of trying to use a USB digital source. Should I be finding a different codec somewhere?
I'd appreciate any comments / ideas about this.

Aphelion · 29 Mar 2010

I don't think it's being put through the PC soundcard but rather through Windows audio subsystem. In this case I think Windows is seeing it as a USB microphone... and must be adding an extra layer of software to add level controls... you would not expect that on a digital input. I doubt if it's being converted to analog, there are digital level controls but the signal will lose some integrity.

Right click on the Microsoft Speaker icon and select "recording devices", right click again in the center of the window, even though it looks like it's selecting a device. Check both "Show Disabled Devices" and "Show Disconnected Devices". By any chance is there a digital input for the preamp, if so, try setting that as the default recording device. Also, check the enhancements tab for both recording and playback devices to make sure there is nothing else affecting the digital audio stream.

Ap

Aphelion · 29 Mar 2010

I wonder if the digital volume thing could be part of DRM in preventing a pure digital copy?

Ap

eddyad37 · 30 Mar 2010

Thanks for the replies.

Aphelion said:

I wonder if the digital volume thing could be part of DRM in preventing a pure digital copy?
Ap

I suppose this is possible - but it shouldn't apply to everything except microphone, surely? I use the pre-amp on a phono turntable for LPs.
Also Goldwave CD extract works OK and just extracts the CD bit-stream.

Re. your previous post - no digital input for the pre-amp, but it's given me an idea wondering if there is a codec around the same as the XP version.

gliebisch · 27 Dec 2010

Would like to know if this was ever solved. I have an Audio Technica USB turntable that was recognized by the Windows XP OS in my old computer as a "line level" input, but in Windows 7 is only shown as a "mic level" input. Seems like a Windows driver problem to me.

eddyad37 · 28 Dec 2010

Sort of solved. It turns out that Windows 7 doesn't support a 'Line-Level' input as such. You just have to turn the Record volume down until it's acceptable. Have a look at the first item on this page Applied Research & Technology: Technical FAQs which I solved with the makers help, who then posted the guide. It would apply to any line-level output device.

gliebisch · 28 Dec 2010

Thank you Eddyad37! I knew that once I heard from someone else who had been through this, I could at least save myself additional hair pulling! It is amazing how many responders are out there who have no clue what they're talking about, but like to see their response in print! You are NOT one of them! I don't think the Microsoft solution is very elegant. In fact, I think it's a pretty sloppy way of addressing this, but it is what it is....thanks!