Qualities of galvanic isolation

There are obviously steps and differing qualities in digital galvanic isolation. PS Audio has pushed the envelope again with the galvanic digital lens.

Let’s say… I have a Schiit Eitr box that takes PC USB and passes it through isolation transformers and converts the output to coaxial.
How far am I from the bit clarity achieved by PS Audio’s new transport with my Eitr?

What is the galvanic digital lens? I had a DAC with a digital lens and that was just a reclocker.

I assume any connection that does not have power or a common ground is galvanically isolated, such as wireless, optical, fire optic, CAT ethernet. Several brands of servers use CAT ethernet for data output, the one I have also has an isolation transformer in the output socket. I don’t know why it is necessary, but it’s there. Then there are all those Sonore optical devices, apparently very effective.

PS Audio has meticulously designed a digital lens for their newest transport, it’s surely “just a reclocker”, a well designed one that is galvanically isolated with an air gap.
People are saying that CDs and SACDs are now sounding revelatoriously better, a step forward…

I wonder, why did it take so much time to invent this magic component? It’s all in all a simple concept, though surely it takes quite a bit of engineering work.

Did PS Audio design the galvanic isolation feature of their Perfectwave SACD transport or did Marantz? The PSA transport utilize a Marantz SACD transport / drive which debuted in 2017 with galvanic isolation. The Marantz model is the SA-10.

Paul did say in one of his videos that they (PS Audio) have had a long journey in designing their galvanic digital lens and expressed happiness in the completion of the project.
So apparently it’s house-made?

The Marantz SA-10 was launched on 1 December 2016. I recall as I bought my current system in that month and both make use of extensive copper plate isolation and with the PM-10 was very attractive, if they were not so big. The SA-10 introduced a new SACD transport and extensive galvanic isolation, specifically between transport and DAC as it was also intended to be used as a standalone DAC.

I don’t know about their earlier models (I last bought a Marantz around 1990), but they do not appear to have had digital inputs.

I had the PWD Mk2 which had the “Digital Lens”. These names only serve to confuse me. I understand it was just a reclocker. It was intended to clean up digital sources. The manual said it meant you could feed it any ‘dirty’ digital source. Makes sense, that’s what reclocking is aimed at, I suppose.

I wonder how a reclocker compares to a galvanic isolator for digital signals. The Schiit Eitr is also marketed such that you can feed it any dirty digital signal.

FYI, the concept of galvanic isolation and the digital lens are two different things addressing two different digital performance improvement goals. The former looks to tame noise. The latter looks to tame jitter.

From the PS Audio description of their new SACD transport:

“New to this model—and for that matter, any disc player ever made—is our galvanically isolated output stage. By coupling the output of the drive mechanism to the PST’s internal Digital Lens by nothing more than a pulse of energy across space, any hints of noise or ground contamination are eliminated.”

[Source: https://www.psaudio.com/products/perfectwave-sacd-transport/]

The “air gap” referred to here is intended to drop any noise that is being carried along with the ones and zeros, allowing just the bits to head out to the DAC.

And here is a description of the Digital Lens “technology” from Paul McGowan back in 2015:

“The Digital Lens is a regenerator for digital audio. LIke the venerable Power Plant AC regenerator, a Lens recognizes incoming data, throws away the original, rebuilds new and jitter free digital audio before the DAC gets it…If timing (jitter) were to blame for variations in sound quality, I had imagined we could prove that by removing the suspected clock/data relationship. We know jitter does not occur in stored data without reference to a clock. It is only when that data and clock are paired we risk jitter…Thus, the audio RAM buffer was ‘invented’ to solve sonic differences.”

[Source: The Digital Lens – PS Audio]

Apparently, improvements have been made to the application of the Digital Lens/data stream buffer and the amount of bits stored and “regenerated” in the current iteration deployed in the PST transport is much less than in previous iterations.

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Sometimes the simplest concepts are the most difficult to pull off and make work.

Consider that for a number of technical reasons the communication between the galvanically isolated output Digital lens board and the main mother board must be two-way and cannot have too much latency. That may sound trivial but when you are working at speeds in the megahertz it becomes problematic.

Other problems are even less obvious. For example, to be truly galvanically isolated it means the output connectors cannot be connected to the chassis (because the chassis is electrical ground). Ok, no big deal, use some isolation washers. Only these would have to be custom since no one but crazies like us do this kind of thing. But, worse, as soon as there’s an isolating ring around a connection to the outside world we get RF leakage through the virtual hole. Now we cannot pass CE and FCC emissions. The list is endless. Every turn seems to unveil a new set of problems to be solved. And I haven’t even discussed the AC requirements of separation, the isolated transformers, etc.

It may be simple in concept but then it’s the proper execution of a simple idea that becomes rather complicated.

In the end it’s all worth it. The years of engineering that is.


Is a high quality isolation transformer substantially worse in terms of losses and what have you?
Again I bring up the Schiit Eitr, which passes any dirty USB signal through isolation transformers and outputs in coaxial. This is surely far from the digital isolation performance of your lens, but how much?

The galvanic isolation of the PS Audio SACD output stage sounds much the same as between the SACD output and the DAC in the Marantz SA-10 back in 2016.

The circuit boards look the same as well.

Tsk tsk tsk…
Well, what is the MSRP difference?
Marantz is 7k€ here. Somehow can’t find the PS transport’s price?

6500 or so in the US.

The jury is still out on the house made, apparently.
But it sounds great in my system, so I don’t care :grin:

The SA-10 was meant to be the ultimate in sensible SACD players / DAC. They did a slimmed down version for $3,000. Compares to $12,000 for the PSA combo.

The SA-10 is $6999 in the US.

“Every solution has a whole new set of problems” is the mantra that my business lives by. There is no free lunch.
I give all of the high performance stereo manufacturers kudos for continuous improvement in the face of all of the outside forces and naysayers.

This is impressing and when you describe such things it sounds as if innovations lie on the floor as no one else takes the effort to realize them. Is it a fact that innovations are clear and just no one has the patience to realize them or is it more difficult to find out innovation ideas?