[adhoc]

Bear with me here:

I run USB out of my laptop into a HagUSB USB-to-SPDIF convertor, which is then connected to a dac.

Like this: laptop > usb > hagusb > spdif > dac

I've always wondered whether my laptop put out a bit-perfect signal. Like many members here, I do not have a DTS receiver so I cannot stream a DTS encoded signal out of my laptop to check this out.

However I think I may have found a much simpler way to check for bit-perfectness.

1. We all know that the Windows native sounds work at 48khz - an easy to test example of these 'native sounds' that I've chosen is the 2 toned sound when you plug/unplug an USB device.

2. If music is playing, and you CAN hear simultaneously this 2-toned sound, does that not means that your audio stream is being resampled to 48khz as well?

I've tried this with foobar, ASIO4all and my DAC. Windows XP. The default device for windows sounds was set to 'USB audio DAC' in the control panel.

Here are my results:

a. combination 1 - waveout via 'USB audio DAC' - I can hear the 2 toned sound no matter whether music is playing or NOT.

b. combination 2 - ASIO4all via 'USB audio DAC' - I can ONLY hear the 2 toned sound when music is NOT playing. When music is playing the 2 toned sound does NOT appear.


Opinions anyone?

 

[mikechai]

That can't confirm bit-perfectness. It just ASIO gives direct access to the hardware and while playing music on ASIO, your windows application can't access the hardware and therefore no 2 toned sound.

 

[trains are bad]

Could you explain how you set up foobar, Asio4All and your USB dac? I have all the ingredients, I'm just not sure how to put them together. I didn't know if you could even use ASIO with a USB dac.