Originally Posted by FMW
No. The circuitry after the DAC chip is quite linear - even in a cell phone. It is just an op amp basically.
Level matching is critical because it makes it easy to distinguish one unit from the other whether there is an audible difference or not between the two. There is no point in making a bias controlled experiment without level matching because you will get 100% result every time. The difference in level creates an audible difference all by itself.
I understand what you believe and why. I was there myself for many years until I actually did the tests myself. The problem on this forum is simply that you are debating with only part of the experience. We all have hearing bias. Very few of us understand that, however, because very few of us have done the comparisons without it.
There are plenty of audible differences in audio but modern DACs aren't one of them.
Thanks you FMW, yours are the only replies that have content, and i appreciate them.
(1) Why should there be level differences if the DACs are all the same and the analog circuitry is so linear?
(2) I went back and reread the OP and early posts. The title of this thread is a question, but the intent from the start was a statement: There is no audible difference. That is a given.
(3) I used to be an advocate of that position, and I still believe the transduction processes (microphone, speakers) are where the big action occurs. My listening preference tends to small classical and jazz groups, but I do occasionally listen to large orchestrations. I like a sense of openness or air that reminds me of the many jazz groups I've heard in soCal and recitals I've enjoyed at Stanford. But then I replaced my Proceed PAV and Amp 2 with a Sony receiver to simplify my setup. It was as though a soufflé went flat. All the notes were there but the sense of openness had gone. I had/have a Marantz Model 18 receiver that sounded superb driving the old AR3a speakers, so i was surprised. The KEF Reference 102s should have been easier. The PAV and Amp 2 went back into the setup and I gave away the Sony receiver. What I listen for is difficult to describe, but I know it when I hear it. The Hamonia Mundi recording of Corelli Opus 6 No. 1 with McGegan and the PBO is a litmus test I use when evaluating a system. Is the sense of spaciousness present or absent.
(4) As one who used to do psychoacoustic research, I'm aware of hearing bias, but I'm also aware how difficult teasing out psychophysical correlates can be. I used balanced experimental design with many trials and many listeners so I could evaluate the all important interactions, not just main effects. The physical correlates for something like i listen for is difficult to pin down, but I can do the present/absent dichotomy.
(5) Do I think you need to spend big bucks for fine sound? No. I often advise my friends to get an Oppo BDP 105 as disc player and processor, a decent amp, and a pair of something like the KEF LS50 speakers. All my equipment except for the Oppo was purchased used, often at 10 cents on the dollar and never more than 50 cents.
I enjoy intellectual discussion; I just don't enjoy the mud slinging so common in this thread but not elsewhere at AVS, the Asylum, or Audiogon.