iMac Sound Quality


Has anyone compare an iMac using it's optical digital output to feed an external DAC, to other PC based alternatives like the SB2/3 or USB SPDIF converters?
kana813
I have an Apple Powerbook G4, which I've used to feed a Musical Fidelity Trivista DAC 21 through the optical out on an Apple Airport Express. The sound quality was better than the sound quality directly through the analog out on the Airport, but it never lived up to all the magical reviews I've read about the DAC 21. I never hooked the DAC 21 up to a CD transport to find out whether the limiting factor was the DAC or the Apple Airport Express optical out, but I'll bet it was the Airport. Recently, I purchased a Scott Nixon USB Tube DAC, and hooked it up to the USB connection on my Powerbook. I've been very pleased with the results, which are much better than my experience using the Airport/DAC 21. If your iMac is close enough to the stereo to use a USB DAC, I would recommend it. I'm using a 15' USB cable, and it works fine.

Hope you find this helpful.

Mark
Mark- Thanks for the feedback. I'm hoping the iMac's digital output connection is better than the wireless Airport Express or the SB3's digital output.
I'm not positive about this but, in general, I think you are better off when you use the USB out than a other out's.
"I'm not positive about this but, in general, I think you are better off when you use the USB out than a other out's."

Pardales- the USB output is powered by the PC's PSU and will transmit it's noise to the USB converter/DAC. The iMac's digital output is fiber, so the PC's PSU noise is isolated from the DAC.

Of course there's the issue of which output has lower jitter.