Looking for Better Jitter Reduction in a DAC

Actually, I just purchased the 1.2 from eBay for $190. A great deal IMO.

If anyone cares, I have a few moments to type..... I had an old laptop running Windows XP as my player. This PC sat in my equipment rack and was a real challenge to get bit-for-bit out of it... XP was not that sophisticated and I had to remove some of Microxoft’s kernal programs... anywho.... I took the SPDIF out to an M-Audio converter to optical... then to the Audio Alchemy, then to my Accuphase (Accuphase has both optical and RCA ins). Foobar’s kernal streaming driver worked well. Since the Accuphase is both a DAC and player, I could put a CD in the tray and A/B the exact same bit stream from my computer...... I got it 99% there.... jitter was a big problem so I understand your real needs.

Then I dumped that whole rig and purchased a Benchmark DAC1 with native USB port and one that touted no jitter. Life got way easier.

I was using a pair VTL 300 Deluxe tube monoblock amplifiers and one just died... so I just received my new PrimaLuna HP intetgrated amp.... I chose an integrated so I could hook up more than one source..... so now I could pull out my Accuphase and A/B with the Benchmark... and hook up some old stuff like a tuner etc...

Now I am back to using that Accuphase... it just sounded so much better than that dead sounding Benchmark.... I dumped the Audio Alchemy but could never part with that wonderful Accuphase... now I need something back again with native USB interface with Windows 10 hence the MUTEC (temporarily, I am using the M-Audio Transit product that I will retire.)

An interesting lesson here...... the Benchmark DAC 1 was generations ahead of the Accuphase but it didn’t sound as good. The lesson here is that just because there are newer chips out there does not mean the old stuff sounds worse...... as we old guys know, it is all in the details of implementations and the subtly of designs. The Accuphase used four stereo DACs in some goofy configuration that sounds beautiful.... I have no idea what they were doing but they did it right.

There is more to this story (more like a journey), so some of the equip configurations above may not make sense... lotsa stuff came in and out over the years, but I thought I would share the highlights.

Peace
Bruce in Philly

Interesting.......

I plan on dragging that older Accuphase to a good store and comparing it to some of these modern units.... I am rooting for the Accuphase simply because it sounds so much better than a Class A rated DAC, the Benchmark DAC1.   Again, the design of the Accuphase is that it uses multiple stereo DACs..... who knows, maybe these guys discovered something great.  From their manual:

"The MDS (Multiple DeltaSigma) principle em-ploys several deltasigma type convertersin a parallel configura-tion which results in adrastic precision enhancement. The delta sigmaprinciple combines oversampling with noise-shaping (a kind of digital feedback) which projects the amplitude information of the digital signal onto a time axis for precise conversion.Figure 1 shows several delta sigma converters which are fed with the same signal and whose outputs are combined to arrive at the overall waveform. "

Sounds good to me.

Peace
Bruce in Philly

I find it very odd that SPDIF coax, i2i, and optical from transport to DAC all sound the same. I’m using the highly rated Lifatec glass optical cable and an Empirical Design 1.5m coax.

I’m starting to wonder if the problem is the output of the DAC. I'm using the unbalanced output from a fully-balanced DAC. Preamp and amp are both SE.
DAC output is 2.8V RMS (unbalanced).

@bruce_philly

How old is the DAC1 you are comparing to the Accuphase?

That DAC1 runs pretty hot. I think it might need a recap after 10 years possibly due to the internal heat causing aging of the caps. You should be comparing to the DAC3 these days. The DAC3 uses 512 delta sigma DACs over several ESS Sabre 9028 chips. Basically this design is a hybrid between a ladder R2R and a single delta sigma 1 bit DAC. This type Sabre chip is where performance minded DAC conversion is heading - the best of both worlds - high linearity (from 1 bit delta sigma) and low noise (of ladder style design) - achieving 9 bit resolution and extremely low noise a far cry from old single 1 bit sigma delta methods of the 90’s.