Gremlins Emerge with Switch to Windows 7


I have had generally good PC audio experiences using Windows XP.

In fact, I have viewed with skepticism a lot of the PC optimization threads as I found with USB into external DACs it was pretty straightforward to get pretty darn good sound.

So I am dismayed tonight to have finally purchased a new, and much faster laptop which operates with Windows 7.

In an A/B comparison with my old laptop, using the same USB cable into my desktop system, the new laptop sounds HORRIBLE.

Can anyone please offer a simple, lean and mean configuration in Windows 7 for exporting audio via USB?

Thank you,
cwlondon
CW,

Sounds like that "Levels" tab may be a digital volume control (always a big no no since they trade resolution when controlling the volume). Try setting it to maximum and see if it sounds better.

Dick
CW,
Make sure you are bypassing the internal windows mixer. SPDIF settings should not be coming into play when using USB output. In another current thread (near the end of it) here somebody posted a link to the dCS "cookbook" for setting up computers (MAC and windows) software to get "bit perfect" output. Reading a file, converting to PCM and sending the bit stream to USB port is a simple task that requires little resources. You just have to make sure that software stays out of the way as much as possible and not tamper with the bits.
since this is a laptop its likely that you are only willing to go so far, i.e. you have to strike a compromise between a dedicated server and a multitasking machine. The biggest degradation to audio transparency is (a) the audio hardware limitations (b) the jitter introduced by cycle stealing between computer processes... your audio card may have practically no jitter in a test lab situation but in a real life PC that doesn't happen without tweaking.

1) run your laptop off outlet power

2) setup a custom power configuration with all hibernate/sleep/idle options disabled... anytime the machine has to rouse hardware(video/CPU/HD/USB) from a power saving state it introduces audio degradation

3) if your BIOS has power saving options, note the defaults and disable (video/C1E) when playing music. Restore when on battery or your battery life will suffer

4) analog laptop sound card output is usually not great. Use ASIO if your only choice is analog out. Otherewise try to use digital to an external DAC. Kernel streaming is actually better than ASIO but can be more challenging to get working without stutters and dropouts

5) get DPC latency checker from Syscon. try to get your latency below 300 microseconds

6) once you have your latency cleaned up disable all audio buffering in your playback program or put to the minimums possible. I find that when I increase the buffers beyond the minimum for the output mode, the stereo image collapses.
CW, here's the link I was talking about: http://www.dcsltd.co.uk/page/assets/dCS_Guide_to_Computer_Audio.pdf.