Jitter reduction, best device?

There is a renewed interest in jitter because of the new PC-based servers. The data from a hard drive is read in blocks without an inherent clock. An SPDIF clock is generated at the same time that the SPDIF data is created. It's this clock that has the troublesome jitter. Most PC manufacturers and even sound card manufacturers don't care that much about jitter. It's only a few audiophile nuts like us who are concerned about it.

I'd like to see SPDIF jitter measurements standardized and published for PC's and PC soundcards that output SPDIF signals. Then we could really tell how bad the jitter was and whether we need outboard jitter reduction. (The SPDIF signal is what goes between the PC and the DAC, either in optical or coax cable)

I'd be skeptical of any device, like PCs, not specifically designed for good sound.

DACs like the benchmark and others that re-clock during upsampling would seem to be the way to go when the source is a generic computer.

From the sound of it in my system, the Roku Soundbridge seems to do a very good job caching/buffing the bits received over the wireless connection from the laptop PC server and then providing the clock and delivering bits at the right time to the mhdt tube DAC.

The Roku has been a fantastic $129 investment for my system.

Well I've now tried the Monarchy DIP Classic (non-upsampling) reclocking device with the Wadia 170i and the improvement in resolution was quite staggering - like the noise floor dropped significantly.

I don't know if this is the result of a reduction in jitter or the amplification of the signal voltage by the DIP but I was shocked by the impact. More details can be found in a review I posted here for the Wadia 170i but the bottom line is that with a DAC which doesn't reclock or reduce jitter (AN 1.1X Sig.) this jitter reduction device made a significant difference.

Hens,

the bottom line is that with a DAC which doesn't reclock or reduce jitter (AN 1.1X Sig.) this jitter reduction device made a significant difference.

Interesting. Your observations suggest that for those connecting gear through digital interfaces it is worth investigating this issue when selecting a DAC. For those with a DAC already (particularly an older generation DAC that rarely had anything other than a simple PLL), this points the way towards a postential improvement.

Shadorne, that certainly fits with my findings. I intend to see if I can borrow a benchmark DAC or DACMagic in the next few weeks to see if the DIP makes a difference with a DAC with its own jitter reduction system. I would expect much less impact in such a scenario but if there is still a significant difference it could also suggest that the strngth of the signal is also an important factor as the DIP amplifies this signal from around 0.5 volts to 5 volts. Should be interesting.