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

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.

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).

Cjnolan - good advice: buy direct! I bought my DAC1 direct in spite of lower total price at Sweetwater (same price but free shipping). Buying direct gives better support and most likely newest revision. Buying used is a little bit risky since early Benchmarks DAC1 had some problems (thin sounding amps and very high output impedance on RCA outputs).