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Looking for Better Jitter Reduction in a DAC

I'm looking to improve the jitter control in my digital setup, which hopefully will create a more analogue presentation. I own a PS Audio PW Memory Transport, which sports a FPGA, and a Nuwave DSD DAC with a scaled-down version of the gate array.

   I have owned a Chord which uses this technology and it was like listening to analogue recordings. I sold it only because it's soundstage was very forward, like sitting in the front row of a concert hall. My current PS Audio setup has wide and deep imaging, as does my Atma-Sphere preamp.
   I have auditioned the Schiit Grundir and it was a bit too fast in the attack and transients, but had the dynamics and deep imaging that I like. So, I guess what I'm looking for is a unit with a laid-back, realistic musical presentation.

The Mytek Digital Stereo192 DSD and Blue Circle DAC are in my price range, but there is no way to audition them.
  So any recommendation and advice is appreciated. DSD preferred, budget is about $1200 used.


128x128lowrider57
audioengr
3,282 posts
 

It is quite easy to go down the garden path with digital.  There are a lot of variables, even when using a transport, including jitter, digital filtering in the DAC and DAC output stage and power system.  Any of these can make it sound "digital".

The best way I have found to approach this challenge is to focus on one thing at a time and optimize it, eliminating that effect as a cause.

The first thing is to eliminate jitter.  Trying to do this by selecting a particular DAC just confuses things.  Most DACs with resampling in them change the jitter and thereby the sound, but never never eliminate jitter, or even reduce it to inaudible levels.  The source must be optimized in order to do this, whether its a transport, USB converter, server, computer or network renderer.  With most transports, the best solution is a reclocker, unless you are willing to spend $20K for a transport, which is IMO ridiculous.

Optimizing the DAC digital filter is harder.  There are several approaches:

1) DAC that has discrete D/A implementation and custom filters

2) NOS or ladder DAC that has NO digital filtering

3) DAC that has selectable filters

Optimizing your choice in output stage has several options:

1) tube output stage

2) discrete transistor output stage

3) minimum # of op-amps in the output stage

4) active output stage with feedback that linearizes the behavior

Optimizing the DAC power system is much harder.  With some DACs that have external power supplies, you can upgrade and improve this.  Adding an AC voltage regulator like the Plasmatron from VHaudio.com helps a lot, but not inexpensive.


IMO, trying to use cables or filtering to make it sound more analog is the wrong garden path.  It ultimately sacrifices dynamics and detail.


Steve N.

Empirical Audio

lowrider57's avatar
lowrider57 OP
5,418 posts
 
I appreciate your comments, @audioengr . I contacted you recently regarding a Synchromesh purchase and appreciate your no-pressure-to-buy attitude. I'm following your advice and focusing on each element one at a time. First, I addressed the power delivery and chose a good quality shielded cable as suggested, rather than the cable which uses ferrite filters.

As for my source, I'm concentrating on Redbook playback first and am using a PSA Perfectwave Memory transport. This unit outputs a signal which has been reclocked from a buffer and not from the spinning CD. I actually don't hear much difference in sound quality between the HDMI (I2I) signal and the optical or 75 ohm coax. I'm now using a 1.5m BNC coax which presents deeper imaging and more low-end extension than the other formats.

I took the advice to remove the preamp from the chain, and the result is a much smoother presentation without harshness. I believe the DAC's output of 2.8V RMS is overdriving the unbalanced inputs of the preamp.
In any event, the sonics from a DAC-direct hookup is still not what I would call "analogue-like."

audioengr
3,282 posts
 

If the jitter is truly low from the transport, then the problem is likely the DAC.  If the DAC does not have a good volume control technology in it, this could be the problem too.  Perhaps not that much better than the preamp, just different.

I want you to try modifying the CD disks themselves.  This will lower jitter even more.  There are several steps you can take:

1) get a really good treatment solution from Jena Labs and treat the disks.  Spray it on and then rub with a lint-free cloth outwards.  I believe they provide the cloth.

2) try putting the disk under a fluorescent light, up close for 20 seconds before you load it

3) use a degausser, like those used to erase the older cassettes on the top of the disk - this removes charge

4) the best treatment is actually to put a rubbery coating on the top of the disk, avoiding the center where it is chucked


Another thing you can do is rip the CD and then rewrite it to a Mitsui Gold audio master blank disk, after treating the blank disk.

It's actually must simpler just to rip the disk and then play it back using a computer audio solution, like USB or Ethernet.  I also makes your entire library more convenient and you don't have to listen to tracks that you don't like.  Jitter will be much lower than any transport too.


Steve N.

Empirical Audio

dlcockrum's avatar
dlcockrum
2,190 posts
 
Looking forward to reading your results from this advice lowrider. I have all of.these tweaks (Jena labs CD polish, AVM, Acoustic Revive CD degausser) from years of trying nonsense and would be glad to loan them to you as I found them to be a complete waste of time and money. 

You already have a great transport that buffers and reclocks so none of this makes any sense excepting a better DAC which I suspect to be Steve's endgame anyway. He does make a good one. 

Best of luck to you lowrider.

Dave
audioengr
3,282 posts
 

I bought this plastic spray from Home Depot and put a shield over the disks I made from thin card stock to protect the center hub.  This rubbery coating makes a BIG difference.  You used to be able to buy rings made of similar material and glue them to the disk.  The other things make a small difference, but audible if you have a resolving enough system.


Steve N.

Empirical Audio

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