The truth about Apple/iTunes volume control?


Hi - I've always understood it's best to use the maximum volume setting on your computer when playing back music, controlling the volume with the amplifier. That has always worked for my ears, but now I have a new source (a USB DAC) that appears to be getting overloaded by the maximum signal from my Macbook Pro running iTunes.

I'm wondering if it would be possible at this stage of Apple and iTunes' development to lower the volume without losing bits. There seem to be recent reports saying yes, and one forum member said worries about lossy digital volume control were a "myth," although others disagreed. Today, I was told that it's OK to lower the volume on the computer to its "native level," a setting in the middle, or close to it, that is the default level when you first turn it on. I've got a Macbook Pro that has an overall volume control I'm wondering about, in addition to the iTunes. Unfortunately, it seems to be remembering my previous settings, such that I don't know what this native level is.

So, does anybody have any definitive answers on this?
coverto
I'm a little taken aback that the identity of my DAC has drawn such feverish speculation. Thanks for all the interest, but I'm just wondering whether turning down the volume slightly on the Mac's overall volume control and/or the iTunes volume control can be done without losing bits, and thus solve my problem. Am I grossly oversimplifying this?
It is not the identity of the dac per se- it is the fact you won't share it. Completely bizarre.

Quite frankly you don't deserve a response.
Robr45- I don't see what's "completely bizarre" about being reluctant to drag a manufacturer's name into a discussion thread where a lot of folks seem to think there's a scandal brewing. In my humble opinion, your hifalutin tone is what's bizarre. On the other hand, your earlier post was extremely helpful. Thanks for that, whether I deserved it or not.
Converto,
A few have already mentioned that the current iTunes does not lose any quality with a lower volume setting in iTunes--as far back as iTunes 7. Looking for specific proof? Google/Bing "24 bit volume itunes" you will see references from Benchmark (DAC mfgr), Stereophile, etc.

Your comments about the Macbook pro are a bit confusing when referring to "Native level" what is that?

Why you are asking about the system volume/level is a bit confusing itself. The system volume control is not used with a USB DAC (not with mine any way) FWIW I use a Wavelength Brick DAC--the Mac's system volume is disabled (it moves but does not change output level). And iTunes volume works as expected.

Does anyone who uses a USB DAC with a mac, have a system volume (not iTunes player volume) that is functional while the USB DAC is the chosen output?

AG members are likely asking about which DAC you are using, because there may be in issue with that DAC. It is the DAC's duty to provide a signal to the mac to allow it to be chosen as the output device in Mac's Audio Midi Setup. Is your DAC showing up as an output option in Audio Midi? knowing which DAC may allow some who are familiar with that DAC to possibly provide a solution for you or let you know that theirs works or also has problems.

Hope that gives you some leads to track down the issue with your DAC.

Cheers, Ed
I had an overloading issue for a while. I suspected that my Lite DAC-AH was sending too much signal to my pre. I blamed the DAC. For a while I adjusted my iTunes volume down a bit and it went away. But then it came back a few months later. What it turned out to be was a pre-amp tube that was on its way out. I replaced it... problem gone. Sometimes it not what you think.