Something rather left field re DirectStream DAC


Hi Paul

I would rather have sent this via PM, but you don’t have the option next to your name the way the others do. I think I have something that you will be interested in and wanted to confide in you.

I watched your videos and especially the one with you and Ted Smith being interviewed by Steven Rochlin. In that video you said you were amazed of discovering new detail from even the humble CD (or 44.1KHz files). You mentioned the Shelby Lynne “Lovin’” track with which I am familiar.

Then you guys joked that in ten years time we would find even more detail in CDs.

Ten years wait? Well, maybe not?

I have is a suggestion for you, something right out of left field. It boils down to a realisation of something that nobody has thought of before and they should have thought of it and didn’t. Maybe, because it is so counter-intuitive, that also helps explain why.

So I hope I have you interested.

I won’t post here exactly what we did down here, that is something I would like to convey directly for your consideration.

But first, may I introduce myself, my name is Joe Rasmussen. Not sure if that name means anything to you, but I was THE long-time collaborator with the late Allen Wright, from 1975 to 2011 when Allen passed away. But that name should certainly be familiar to Arnie Nudell as he had a Sony SCD-1 (the twin model of the Ted’s Sony SCD-777) and, if memory serves me right, it was Bascom King who suggested to Arnie to send his SCD-1 to Bill Thalmann (who had then retired from ‘conrad-johnson’) to get the Vacuum State/Allen Wright upgrade done to it. And that is what Arnie did.

Now I see on that video with Rochlin, that Ted Smith’s “Proof of Concept I” was a Sony DVP-9000ES, a very familiar model to us too. It had the VC24+ chip that you can see in Ted’s picture, how the caps and transformers are wired into the VC24+ chip. Of course Arnie’s SCD-1 also had the VC24/STAC chipset - and Allen did something very similar to what Ted did in the first “Proof I” and we did a number of DV-9000ES and Allen too owned an SCD-777 that Ted also did - and that leads me to the story:

Around 2001 Allen met Ed Meitner, the father of DSD, at some function and asked him an interesting question, one that Ted would likely have asked, can you recover the analog from DSD by just using a Low-Pass Filter? Ed Meitner avoided answering the question, but Allen persisted in asking if it would work and eventually Ed Meitner blurted out: “Of course it will work.”

That led Allen to do something so similar to what Ted later did in 2007, except he did not use 1:1 transformers, but a Unity Gain stage, so the output was the same as the 1:1 transformer, about 600mV RMS in unbalanced mode and 1.2V RMS balanced, same as Ted’s.

So it is interesting how great minds think alike - and of course this was also what Bill Thalmann did to Arnie’s Sony SCD-1. So Ted’s “Proof of Concept I” is not far from what Arnie Nudell had owned before. Now I hear that Arnie involvement in voicing the DirectStream, I wonder if he knows the connection with his old SCD-1? He probably doesn’t have it anymore, but it was quite a monster.

A few weeks ago, I hit the road, went to Queensland (sort of our equivalent to Texas, if you know what I mean), to meet up at Southport Hi-Fi who are PS Audio dealers and they have sold a number of DirectStream DACs. One of the partners in the shop, Tony Wong also works with Magenta Audio, your Aussie importer. The other partner is Mike Lenehan who designs loudspeakers. The three of us go back many years indeed.

So we had an official Southport Hi-Fi “Get-Together” with Mike Kirkham and Peter Foster from Magenta also turned up, coming up from Adelaide. Indeed it was Mike Kirkham’s suggestion, that I should get on to your forum and play this past you.

So we had the three main-stays of Magenta Audio there, and we were playing Mike Lenehan’s new speakers and new gear from PS Audio. And of course the DirectStream DAC was center piece and were all familiar with. Keith Eichmann is a friend of mine and he was there as well, he is of course the inventor of the Eichmann Bullet Plug. So it was an interesting day and interesting people.

Now for the serious bit. When the day had slowed down, Mike Lenehan and I tried an experiment with the DirectStream DAC, as I said, something pretty left field. Relax, it did not require opening up the DirectStream DAC and no surgery. Let’s just say what we did was interesting and something you wouldn’t normally do. Not weird ‘new wave’ stuff, but something that required a degree of expertise and based on rational thinking.

Rather than post it right here and now, for all to read, as a mark of respect I feel I should tell you privately exactly what we did - that way I would respect your decision where to take this. But truth to be told, many would have the ability to try this out for themselves right now, as it is not that hard to do.

Whatever you could say about the result, Mike Lenehan’s reaction was instant and and dramatic. It was after all his own system and he was more familiar with it than anyone else there. Not sure what Mike Kirkham and Peter Foster heard (they came into the room later, after we went outside) although we had discussed the subject in a group earlier in the day.

But Mike Lenehan later told me that Peter Foster had certainly heard a difference, but was less committal - but those familiar with the system were more than just positive. Tony Wong, the third cog in Magenta, he asked me bluntly and sternly: “Joe, what are you going to do with this?” That is a good question. He could see that this had some kind of value to it, and typical Tony. But what to do? Only got some ideas about it and we shall see.

I need to contact you via a PM or you can use my Vacuum State public email address: and I will explain precisely what we did and you will be able to replicate and make up your own mind. It will strike you an odd thing to do, but you should do it anyway, then put on our favourite Shelby Lynne track, I think you know which one I mean.

So there you have it.

Cheers, Joe


Thanks for sharing, Joe!

I really hope the forum members also can get a glimpse into what was done here, eventually. You certainly made me curious, at least :)


Welcome Joe. Oh man, your killin’ me, but I understand that you’re approaching this with integrity. I’ll bet that, based upon your experience, it’s not magic pebbles!4_gif


Could this be the Schumann Resonator!!!


I have contacted him as requested. Since he’s down under I am guessing he’s asleep. We shall see.


Thanks, Paul

I am intrigued.


Curious indeed. Sometimes another person can see what we are blind to, often because we “know better”. I look forward to Paul’s take on this twist, good or bad.



I’m a cynic - I expect something is going to be for sale and we all need to run out and buy it, or maybe it has to do with a Nigerian Prince. :)

I’m happy to be wrong though.


I share the cynicism.

But I always love the story. :)

gocubs42 said Could this be the Schumann Resonator!!!!!
No its not. I have seen Joe's prototype but not had a listen to it yet. Joe has considerable expertise modifying OPPO players. I have an OPPO 105 modified by him and it performs well. It will be interesting to hear the potential outcome of Joe's endeavours with the DS.


assisi said
gocubs42 said Could this be the Schumann Resonator!!!!!

No its not. I have seen Joe’s prototype but not had a listen to it yet. Joe has considerable expertise modifying OPPO players. I have an OPPO 105 modified by him and it performs well. It will be interesting to hear the potential outcome of Joe’s endeavours with the DS.


Hi John. That made me smile when I saw that - no, when something comes down to passive components I hardly think so. Nothing resonating in this instance. I am in the middle of preparing an email to Paul - he will confirm that it is something different and not totally outlandish.


Lonely Raven said I'm a cynic - I expect something is going to be for sale and we all need to run out and buy it, or maybe it has to do with a Nigerian Prince. :)

I’m happy to be wrong though.

In that case I hope make you happy - I would rather that than see your dollars.

I have been around for a long long time, and I can be as cynical as anybody else, I certainly could tell a story or two, in fact many… like a loudspeaker salesman who preached the gospel of “high frequency dispersion” and repeated it nauseatingly - he was selling Yamaha loudspeakers at a Hi-Fi Show at the old Sydney Showgrounds, now the very soundstage of Fox Studios where the last two Star Wars movies and the Matrix movies were made. Went there one time, due to work and ran into Obi-Wan Kenobi (Ewan McGregor) coming outside for a smoke. Wonder if he has since given it up? confused

Cheers, Joe


Here is my guess - they put a magnet over the transformers.


My guess is ted S has tried this or some thing simaler. But Paul would not allow it for reasons he knows and maybe right.

I have a dac that for dsd is better or at least it I think it is. It’s dsd is very good some thing much better than a DS.

Of courser this is my opinion and not bad junking the ds that I love. The point is bypassing the dsd internally for dsd is along a great idea path. But I wonder why it was not done in the DS.

One consequence comes to mind no firmware to roll or change in sound after the mod for dsd.

Paul I do look forward to you sharing something about this.

Just a thought



Cmon the suspense is killing us…What did Joe R. do?


He proposed a Zobel network on the output. For those wondering what this is, it’s a simple resistor and capacitor in series, placed in shunt across the output transformer of DirectStream. The idea is simple and can be effective as transformers mirror that which is on their output back into their inputs, thus terminating the output of DirectStream and providing a type of rolloff.

We’ve tried this in the beginning of work with DirectStream and did not like the results. In our experience, DirectStream likes as little rolloff as possible and as light a load as is available. Your mileage, as well as his, may vary.


Interesting, Joe’s group all thought it was an improvement, but the PS Audio group thought it was a degradation. Sort of sounds like the PP discussion! Or, perhaps, their little grey cells are swirling in reverse down under causing a shift in the perception of the sound (my apologies to everyone else in the southern hemisphere). And, yes, once again Al got it right!


Dare I ask, what the values in the Zobel were? I understand them in the context of dampening a resonance in a tweeter by upping the impedance associated with this frequency. I’m not sure what the goal was here.


In general a Zobel network is a network that’s added across an output to balance a load so that the source only sees a resistive load. Speakers are often a inductive load so the Zobel includes a capacitor whose value is chosen to match the effective inductance of the speaker making the Zobel network/speaker an easier load to drive for an amp. (In general speakers present a much more complicated load so the ideal Zobel network for a given speaker is much more complicated.)

This can’t be what the Zobel was being used for in this case - a cap/resistor would be canceling an inductive load, but interconnects are a capacitive load. Conversely if the attempt is to cancel the transformer’s leakage inductance, it wouldn’t be welcome. That inductance is a part of the lowpass filter design in the DS.

What’s left is using the “Zobel” network as an empirical filter added to the output of the DS. People are free to add any filter they desire, but in general at best it will be adjusting for interactions between the DS and the user’s system or, more typically I suspect, purely as a tone control. In either case there’s no reason to think that adding the same network to every DS would be welcome by all users.


I certainly wouldn’t entertain filtering the DS and hence buggering up the DACs stunning performance…

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