Use of Preamp versus Digital Volume from Computer


Has anyone done a direct comparison of using a high quality preamp in a computer audio setup to control volume from DAC to the amp, versus going straight from DAC to amp and using the computer to attenuate volume via the playback software?

Not necessarily looking for speculation or general opinion as there's plenty of that to go around, just feedback from those that have compared or have true knowledge of the pros/cons.

I've had 3 different computers and 4 different DACs over the past year or so, where I've used Itunes to control volume (feeding an Empirical Audio Turbo-3). Nothing really for me to complain about as far as sound. I've heard that the Turbo-3 (by way of converting 16 bit to 24 bit) actually helps the quality of the digital volume attenuation.

My system is fairly resolving with the Turbo-3, Isabellina DAC, modded Rogue Stereo 90 tube amp and Living Voice IBX-R2 speakers all fed via either an IMac or Macbook from Itunes.

It's a stupid question for me to pose personally since it's a bit of "if it's not broken, don't fix it". My system sounds fine to me for redbook playback. But curious how much alteration the digital volume control is doing to the digital feed from the computer to the DAC (or in my case the Turbo-3).

Thanks,

Marc
mb9061

Showing 1 response by herman

I'm using a program called Pure Vinyl on my Mac which uses 64 bit processing and a digital volume control. The Mac is hooked up to an RME Fireface 400 via firewire and I modified the outputs to bypass the opamps so I'm going straight off of the DACs to my power amps. It sounds incredible.

You are right that the higher number of bits gives you better results but that has to be done in the software before the attenuation, not after in hardware. I think you would be pleasantly surprised if you tried the Pure Vinyl. They have a free demo. You can use iTunes as the front end and there is a little window with the Pure Vinyl controls that floats on top of iTunes for volume control and moving through the playlist.