[avta]

I would appreciate some input about software volume control. A number of dacs do not have built in volume control. If one does not have or does not want to use a preamp can software volume control work without compromising soung quality?  I'm thinking about programs such as iTunes or possibly Audirvana Plus ( I don't have this so I'm speculating ). Any thoughts?

[toddbagwell]

you can control the volume digitally.

by doing so, you will lose some resolution.

depending on the software/coding of the player, it may be noticeable to you or it may not. some programs simply cut off bits. other programs have up-sampling and dithering algorithms that allow for much more attenuation before significant quality reduction.

the generic answer is to try for yourself and decide if you can tell a difference.

[FullRangeMan]

This is a old prob not fixed yet, in the 90 years Wadia stated his machines lose 1 or 2 bits in resolution with dvc.

[toddbagwell]

from one of my favorite sites for good explanations of things digital audio:

http://www.thewelltemperedcomputer.com/Intro/SQ/VolumeControl.htm

[Noseyears]

From my understanding, software digital volume control works just as well as a hardware controls. As long as it uses the maximum (usually 24 bit) resolution your Dac is capable of.

[srb]

From my understanding, software digital volume control works just as well as a hardware controls. As long as it uses the maximum (usually 24 bit) resolution your DAC is capable of.

Yes, for 16 bit files, which would give you 8 bits or 48dB of possible attenuation.  If you're playing high-res 24-bit files you will be chopping off bits with any amount of attenuation using a 24-bit volume control and 24-bit DAC.  If you have a software player with 32-bit volume control and a 32-bit DAC you will have the 8-bit/48dB volume attention for 24-bit files with no loss.
 
That being said, even when I play 16-bit files into my 24-bit DAC, I still hear reduced dynamics playing at low volumes when using using the iTunes 24-bit software volume control, even though technically I shouldn't.
 
Steve