I need help - Better DAC or NEW CD player?


I am in the middle of purchasing some components for my new system, unfortunately, reading posts on a rainy night on Audigon only makes my "upgradeatitis" syndrom more acute.

The problem is that some time ago, I bought a squeezebox Duet, to use as transport for lossless files. The idea obviously was to get a good DAC to go along with it.

The one I was almost set on was the Dacmagic, which gets very good reviews here and almost everywhere you look. But, on the other hand, I am willing to spend a little more......Now, the thing is my current CD player is a Rotel RCD 1072, and was wondering whether this Dacmagic would give me any improvements if I use the rotel as a transport for it.

Or, I could get for example a Wyred DAC or a Benchmark DAC1 and use the Rotel for transport, but I dont know the limits of the Rotel as transport alone, I dont want to spend 600 more bucks on a better DAC to be fed with 2 "not so good" transports (the Duet and the Rotel).

So I am kinda stuck!! On the other hand I am contemplating getting the Dacmagic to use only for the Duet, and getting a new better CD player altogether, which puts me into another doubt, I dont know if the little money I can for the rotel + lets say 1000 more will really give me any improvements in the system if I purchase a whole new CD player since the Rotel is said to be very capable.

FWIW my amp will be a W4S STI500 and speakers are B&W 803D.

Let me know what you think about this and your suggestions on what you would do.... thanks in advance for all your help!
demianm

Showing 8 responses by kijanki

Demianm - Asynchronous upsampling DACs like Benchmark DAC1 have very strong jitter rejection and transport should not make any difference as long as it is "bit transparent" (no DSP, no volume control etc.). With Benchmark you can use even cheap DVD player (great traction) and cheap coax or Toslink. Rejection of jitter (that is already at about -60dB) is at frequencies of interest (kHz) over 100dB - impossible to detect. In fact Benchmark is clean/transparent to point of being too clean (sterile). I like it but many people prefer more "lush" presentation. Listen first before you buy (Benchmark had free 30 day evaluation program). If you decide Benchmark - get new one to avoid problems of early revisions. Step above Benchmark (and 2.5x price) is Bel Canto DAC3 (with remote control).
Demianm - Toslink creates more jitter than coax but with Benchmark it doesn't matter. Benchmark tested DAC1 using 500' of cat5 cable instead of coax and there was no audible difference. I use, with Benchmark, Toslink from Airport Express and coax from DVD player and cannot tell the difference.
"bits are just bits. Bits are only just bits if they are there at the right time IME."

That's what we're talking about - jitter (noise in time domain). Jitter creates sidebands at -60 to -80 dB still audible since not harmonically related to root frequencies (noise with complex signal). Benchmark's jitter bandwidth is just a few Hz and at kHz frequencies suppression is over 100dB (overall -160dB).

Tricky part is to use the same transport to compare Toslink to coax. Once you have different transports all bets are off. It is not only that one might be not "bit transparent" but might have weaker laser, dirty lens etc. It is not related to price of CDP (cheap DVD players have great tracking) or jitter but just not reading information properly. Some people use green markers etc but I ripped CDs as data (CDP cannot do it working in real time) using MAX program and have perfect long lasting version on my server.

In addition to above Toslink breaks ground loops and therefore in certain situations overall system might sound better (but Benchmark has nothing to do with it)

Easy way to test is to connect transport that has both coax and Toslink and listen on the headphones switching inputs. I don't hear any difference that way and theory says it shouldn't be any but there is still placebo effect. If one believes that there should be some difference then he will be able to hear below -160dB easily.
"The Benchmark is not really async, but adaptive if I understand it"

- You don't. Benchmark resamples data with new asynchronous clock.

"you contradicted yourself. First you said that transports won't make a difference. Now you are saying Once you have different transports all bets are off".

- No I did not. Transports don't make any difference as long as they are "bit transparent". Cheap DVD player might deliver the same performance with Benchmark as expensive transport - not true with other non-jitter rejecting DACs where sound quality is proportional to transport quality (jitter). CDP with dirty or weak laser (or digital volume control or DSP processing etc) might not be "bit transparent". I was merely trying to understand how you can hear -160dB.

I will also restate that spdif cable quality does not make any difference with Benchmark.
"For it to be asynchronous the dac would have to control the cpu and it does not."

I'm not sure where you're getting this stuff from. Asynchronous sampling just means that two clocks are not related. I modestly mentioned limited experience in audio but I know electronics.

Read this datasheet: http://www.analog.com/static/imported-files/data_sheets/AD1896.pdf - (upsampler used in Benchmark DAC1) and look at the title. It says "Asynchronous sample rate converter".

"Quit trying to be an armchair digital engineer by quoting specs." - you really puzzled me with this one. Now I don't know what to admire more - your ignorance or your rudeness.
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.
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.