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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
 

I used to mod DACs, about 20 different ones.  They all had strengths and weaknesses and many had poor design features that were obviously copied from another manufacturer that knew little about it too, even Sony did this.  The most common thing I found was insufficient power decoupling for the D/A chips and the op-amps.  Another thing I found was ground-planes that were broken-up, sliced and diced by traces, causing crazy current return paths.  Another is too many op-amps in series.  These things usually lead to an un-dynamic sound and a thinness, even harshness.  This is the deficiency with most preamps and amps too.  Another typical thing they do is put a 50 ohm BNC for the 75 ohm S/PDIF input connector.  Duh!!


Steve N.

Empirical Audio

audioengr
3,282 posts
 

BTW, its not a magnetic charge, its static charge.  The degausser evidently bleeds it off.  I know that removing static charge helps, however you do it.  Some people put the disk on a large solid piece of grounded metal.


Steve N.

Empirical Audio

lowrider57's avatar
lowrider57 OP
5,418 posts
 
Steve, interesting stuff about some DAC designs. This problem I'm having makes me keep thinking about grounding issues due to the harsh sound.
As far as outside the components, there are no grounding issues; I've tried different IC's (single-ended system), changed PC's, and checked for broken grounds and ground potential with a meter.

What is very curious about all this is that the I2I signal doesn't sound any better than the other connections; the ground and data travel separately in I2I. The reason I purchased an optical cable was to test it against grounded connections.
Now I'm wondering about the quality of the output from the transport. It is a refurbished unit with warranty and I did send it back to PS Audio for a transport upgrade and I have tried 2 different versions of firmware.

Maybe borrowing a DAC is the only way for me to perform a proper test.


geoffkait's avatar
geoffkait
23,365 posts
 
Generally speaking one should get the best improvement by employing both a static charge remover such as Nordost anti static spray or ionizer AND a degausser such as Walker Takisman or Radio Shellac bulk tape eraser.

audioengr
3,282 posts
 

Ground-loops don't generally cause harshness, only HF background noise.  Some reclockers provide galvanic isolation, so eliminates ground-loop.

Cables make a big difference and you should be using the best I2S or the best S/PDIF you can get, without breaking the bank.

The problem with virtually ALL transports is that the S/PDIF output signal has a fairly long risetime.  This makes it jitter-prone at the receiving DAC, and makes the requirement of at least a 1.5m long cable.

Faster risetime from a computer converter or a reclocker will reduce added jitter, but requires a really good impedance match at driver and receiver and the cable.


Steve N.

Empirical Audio

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