I need help - Better DAC or NEW CD player?

4est
Forget my comments about rudeness or ignorance - I didn't mean to offend you. As for bit perfect or not - it is "bit transparent" and no, I don't have meter but reviewers often verify it. CDP will play scratched CDs because it has very loose checksum checking and error correction and but I was talking about CDP processing alone. Some of them have digital volume control - that would make CDP not bit perfect. As long as output of two different CDPs is the same bit for bit the only difference is jitter. Benchmark supresses jitter and allows to use cheaper CDP and digital cables.

Sufentanil - That was exactly my reasoning. I have now DVD player and Airport Express (computer across the room) connected to Benchmark DAC1. According to Stereophile review Bel Canto DAC3 is better (and has remote) than Benchmark DAC1 but costs 2.5x more.

Kijanki and 4est,

The Benchmark DAC and the Wavelength/Ayre DACs are both asynchronous, and neither is "adaptive." Meaning that in both cases the d/a conversion process is accomplished with a clock that is independent of the computer's clock and that is not periodically "adapted" or re-synchronized to the computer's clock.

However the techniques used in the Asynchronous Sample Rate Converter (Benchmark) approach involve some very small degree of interpolation as part of the jitter elimination process, as mentioned on the first page of the datasheet Kijanki linked to, while the Asynchronous USB (Ayre/Wavelength) approach does not.

Charles Hansen's well-written white paper on the Ayre DAC addresses this further and provides some good additional background.

Under what circumstances and to what degree that interpolation may be audibly significant, I have no idea.

Best regards,
-- Al

Al - pretty good explanation of Benchmarks operation can be found here: http://www.soundonsound.com/sos/jul05/articles/benchmark.htm in chapter "Technology". Of course 50GHz frequency is not real and involves mathematical manipulations.

Thank you Al for the clarification. The Benchmark is a great DAC and can be very revealing- worth the trouble. After experimenting with one for the better part of three years, I keep finding ways to get more out of it, hence my initial post about transports mattering. I purchased a hiFace usb>spdif for hi rez (async type like ayre requiring drivers) computer use and noticed it took the usb up a notch. This lead me to experimenting with different connections on it including using my Weiss DAC as a firewire to spdif converter. The only reason I posted in the first place was that if I hadn't tried different transports (and then servers), I would have sent my first Benchmark back. The first transport I tried was an Oppo DVD player that I was looking to replace the DAC section w/. Well, that Oppo (the original), and my current Oppo (983) both suck as tranports, and yet are very servicable with video and as cd players. The same thing with an higher end 50# copper clad SACD player. Of the five transports I tried, 3 were "dull", and the best was a $40 cheapie DVD from Best Buy with an awful picture that lasted 6 months before it quit. I have a hard time imagining that only one was "bit transparent". I also know that it isn't just galvanic isolation as I have tried optical USB and it sounds different than toslink from the same server. In all of these I never had any clicks, spits or sputters (until I tried Pure Music- another story).

The Benchmark was a ground breaking product in my mind, but is not infallible. It can be sensitive to power and its input- both of which Benchmark claims isn't. Ultimately what does one expect for $1000 in this hobby anyway?