The truth about Apple/iTunes volume control?

Ed - thanks for the comments! The "native level" talk was confusing for me too - I was told it's the volume setting your Macbook has when you first turn it on, which is about 40% for the computer itself and 50% for iTunes. So the idea would be that if you've got both settings at at least 60% or 70% you're safe. That's what I was told by a colleague, and it seems to be corroborated by what a lot of folks on this thread are saying.

To answer your question - yes, the DAC shows up as an output option on my midi setup, and the volume control does work with it.

Cutter - thanks, and to your point I think I've either got a problem with the DAC chip, or the power supply that's feeding it!

Jax2 - Above all, thanks for your very valuable and generous commentary here! I don't mean to be coy about all of this. Your "car talk" analogy is quite apt, and I understand how you might be a little exasperated at my reticence about the dac. I guess I'm just being a little protective of a manufacturer that I like, whether that's appropriate in a forum where everybody is looking to learn, I'm not totally sure.

To your point, I did ask the manufacturer who "needs protecting," and the manufacturer suggested turning down the volume to solve the problem.

So, now I guess it's legitimate to ask - is that a totally bogus response from a manufacturer? Should I "out" this manufacturer once and for all for the shoddy operation that it is?

Seriously, thanks to all for the input.

So, now I guess it's legitimate to ask - is that a totally bogus response from a manufacturer? Should I "out" this manufacturer once and for all for the shoddy operation that it is?

I'm hoping that last question was tongue-in-cheek. Again, of every response you have on this thread you are the only one here making any insinuation of wrong-doing on the part of the manufacturer. No one here has suggested that. Of course, at this point, given that fact, I would not suggest you "out" the manufacturer because if it puts anyone in a bad light, it would only be you. I would suggest that you had a very legitimate and valid question from the start and asking it honestly and specifically would have been a much more productive approach that could have been done without casting any dispersions. Obviously you seem to have a good sense of this particular manufacturer, by your reasons for withholding information that might otherwise help you. Given that, why would you doubt that it is with good intentions he suggested what (s)he advised? I guess I'd focus on researching further what they suggested to you and check other resources on PCAsylum and other sites like ComputerAudiophile. If you ask the question again, and wish to continue leaving the manufacturer out of it, I'd just leave out the whole back story of the DAC and just ask specifically about the volume control in iTunes, if that's truly all you want to try to understand.

Jax - Yes, was tongue-in-cheek on that last question. No insinuations, no aspersions. Honestly. Thanks for the advice. Over and out.