Should I go to a Benchmark DAC1 pre in my system?

DNe,

Thanks for the input.

What exactly is the difference between an active and passive pre-amp anyway?

The DAC1 pre is a pre-amp as well as a DAC. Is it active or passive or something else?

According to Benchmark jitter supression -3dB bandwidth is about 3Hz and supression reaches -100dB at 1kHz. They tested Benchmark DAC1 with 1000 feet of cable without audible difference in sound. I've never tried different cables myself - just put 1 foot long 75Ohm Canare RG11.

Kijanki,

I tend to be a bits is bits kind of guy, but realize clock related timing issues could impact how a DAC applies those bits to generate the analogue waveform.

The BEnchmark approach seems to focus on isolating this process from potential timing issues introduced between transport and DAC, so for what its worth, it seems to make sense to me and I like it.

The test data provided seems to support the claims and I have not those test results challenged successfully to-date. So, on paper and based on reviews, the thing does seem like a winner to me even if its not going to be every ones cup of tea (what is?).

I do tend to like the sound of good tube based systems though and my current Carver SS preamp does a decent job of emulating that sound though, so I do fear the resulting sound might veer more towards the SS/detailed/analytical side with the Benchmark in place. Regardless, I'd have to hear the result to know for sure whether I like it or not.

Mapman - Benchmark DAC1 instead of dual PLL (phase lock loop) used in modern CD players to create stable clock for D/A converter locks to incoming clock using crude (but fast) single PLL and then reclocks data with separate high quality clock. This operation is performed at equivalent of 1 milion times oversampling (equivalent to 44GHz). Normaly this would not be possible but a lot (most) of samples are repeats. In order to place output samples to D/A converter in the right moment it performs statistical analysis of the clock's frequency to 5ps accurate and digital filtering of the signal. 24-bit 192kHz sigma delta D/A converter (extra bits come from averages obtained by digital filtering)is driven only at 100k to limit THD (higher at 192kHz). It is pretty sophisticated operation.

There are two schools in audio - to oversample or not to oversample, matter of personal preference. Non oversampling require good transport, expensive digital cables and in general are less flexible. Oversampling asynchronous reclocking brings benefit of jitter rejection. Jitter is basically noise but in the time domain. It converts to noise in the D/A converter. Jitter might also be created when converting old analog recordings to digital tapes using poor unstable clock, like it happened at the beginning of digital. Jitter caused by media/electronics/cables can be removed (reclocked data) but jitter already recorded stays forever. Many older recordings got wasted that way and the quality of the first CDs was "not the greatest" (to avoid profanities). I've heard (might be a rumor) that they digitized analog tapes that contained frequncy correction fo printing LP resulting in extremely bright sounding CDs.

Getting back to Benchmark: it allows me to use cheap transport - $70 Sony DVD player to connect HDTV with toslink and to get CD/DVD sound with coax. DVD players usualy have bad quality analog outputs but very good tracking and have inherently built in MP3 decoder. Some of them play DVD-Audio or SACD (converted to S/PDIF).

And they back it up with a 30 day no question's asked guarantee. Buy direct. Try it. If you're like me, you'll keep it. I have the USB version connected to my MacMini media server (1300 cds) in lossless digital format, along with a couple dozen vinyl records in 24/96 format.

It's easy to get all hung up on specs, I say try it.

BTW, mine is connected into a BAT VK-300xSE via balanced cables. MacMini feeds Dac1 via USB. DVD player feeds Dac1 via COAX.