PS Audio DirectStream DAC

[matthias]

I am getting the MA Purestream DAC which is specifically optimized for DSD256. I will know more and can compare. As far as PCM goes, I have Schiit Yggy and both Yggy and DS has there strengths and weaknesses.

 

Please post your experiences with the three DACs.

 

Matt

[Dev]

I would like to have a direct path for DSD with the least processing inside the DAC, like the direct DSD path in the new AKM chips or T+A 8 DSD or Lampi.

 

Matt

 

Its known that DS doesn't provide direct path and so does many other DSD DACs. You could post this request in the DS forum but I doubt it would make it.

[Dev]

Please post your experiences with the three DACs.

 

Matt

 

I will.

[barrows]

Wow, lots of speculation and misinformation here. OK, a few things:

 

1. After the FPGA, the DS presents a DSD 128 signal to the filter stage, and indeed, the filter stage is a low pass filter made up of both capacitor/resistor elements, and the transformer. It is a multi stage filter, as a transformer alone would not be adequate to filter the DSD stream into an analog signal.

 

2. The DS oversamples (in the FPGA) every incoming sample rate, whether DSD or PCM, to 10x DSD, then down converts to 2x DSD before outputting to the filter stage. Additionally, yes, when it oversamples it also applies digital filtering, as a matter of fact, it is required to apply digital filtering whenever one oversamples, if you do not, you will get tons of audible alias products.

 

3. Almost all DACs have some kind of (analog) low pass filter before their output, but this is very different from using an analog filter as a D to A conversion for a DSD stream. The filtering required to convert DSD to analog is about ten times stronger than what is required at the output of most DAC chips, hence it is quite difficult to do it well, without audible consequences in the audio band.

[Dev]

Wow, lots of speculation and misinformation here. OK, a few things:

 

1. After the FPGA, the DS presents a DSD 128 signal to the filter stage, and indeed, the filter stage is a low pass filter made up of both capacitor/resistor elements, and the transformer. It is a multi stage filter, as a transformer alone would not be adequate to filter the DSD stream into an analog signal.

 

2. The DS oversamples (in the FPGA) every incoming sample rate, whether DSD or PCM, to 10x DSD, then down converts to 2x DSD before outputting to the filter stage. Additionally, yes, when it oversamples it also applies digital filtering, as a matter of fact, it is required to apply digital filtering whenever one oversamples, if you do not, you will get tons of audible alias products.

 

3. Almost all DACs have some kind of (analog) low pass filter before their output, but this is very different from using an analog filter as a D to A conversion for a DSD stream. The filtering required to convert DSD to analog is about ten times stronger than what is required at the output of most DAC chips, hence it is quite difficult to do it well, without audible consequences in the audio band.

 

Very nice and informative posts barrows.

[ALRAINBOW]

I did not say PCM sounds better than DSD with this DAC. What I meant is that it is a DAC for PCM lovers.

A DSD lover should look elsewhere. This is the same that Al meant in his posts.

 

Matt

 

Thanks i asked a few times of a bypass for the dsd in the ds dac. I was told no in the ps audio forums. It was my last hope for good dsd

I figured as it does s filter at the end it could bypass the whole fpga thing. Maybe it needs it for other reasons but TED replied it could not. He also stated it will not play native Nor Higher than dsd 128 either. Clearly there is more to this. Now I do not want to trash the dsd sound it's nice just not what I like. As some firmwares clearly sounded better in pcm or dsd I even asked for multiple formare loads from the screen or even a setup for one over the other for each format. None was accepted . The concept of firmware rolling was also not liked either. I guess it's about improving and old is not as good as the new. While I disagree with this it does have some value as well

[kennyb123]

Very nice and informative posts barrows.

 

+1

[mikey8811]

Torrys has better Midrange richness and bloom than does either Yale or Pikes Peak. 1.21 might be a smidge better in that single regard, but it is inferior in most other ways, plus it doesn't support their streaming card.

 

FWIW: I was a version 1.21 die hard until Torrys.

 

 

I tried Firmware 1.2.1. At the same time I added a Cardas Clear Beyond Power cord to my power amp.

The result was added weight and midrange richness. Slight but enough to make it musical for me. The openness and space between instruments diminished somewhat but I preferred what I heard overall.

I am reverting to Torreys again to try it out just in case it is the contribution of the Cardas Clear Beyond that is giving the sound the much needed midrange bump rather than the firmware. Hopefully, I can get both the midrange richness and the airiness back again but somehow am skeptical.

 

From what I have read here and elsewhere, 1.2.1 is the firmware with the “best” midrange richness. I understand that both Pikes Peak and Yale are inferior to Torreys as far as this midrange attribute is concerned so it is a waste of time to try those. Is this correct?

[ALRAINBOW]

For me 1.21 had weight but was too warm

all the ones after that had less weight and more details closer to neutral

while some did dsd or pcm better never both

I never got to use the new one before is sold it.

[barrows]

Thanks i asked a few times of a bypass for the dsd in the ds dac. I was told no in the ps audio forums. It was my last hope for good dsd

I figured as it does s filter at the end it could bypass the whole fpga thing. Maybe it needs it for other reasons but TED replied it could not. He also stated it will not play native Nor Higher than dsd 128 either. Clearly there is more to this. Now I do not want to trash the dsd sound it's nice just not what I like. As some firmwares clearly sounded better in pcm or dsd I even asked for multiple formare loads from the screen or even a setup for one over the other for each format. None was accepted . The concept of firmware rolling was also not liked either. I guess it's about improving and old is not as good as the new. While I disagree with this it does have some value as well

 

AL: you are probably asking for the impossible, I am speculating a bit here, but I suspect there are reasons why what you asked for are not possible:

 

!. The FPGA is responsible for clocking/aligning the data stream, hence it cannot be "bypassed", additionally, there would be no volume control without the FPGA.

 

2. The FPGA has limited resources, and PS Audio is already asking it to do a whole lot of processing. It is very likely that it would not be able to accommodate two entire firmware versions at once.

 

3. The D to A stage (or filter if you prefer) requires to be fed DSD 128, so even if one could bypass the FPGA, then one could only send through DSD 128. Since the filter is optimized for DSD 128, it is very likely there would be way too much noise if one sent DSD 64 through to it.

 

Clearly you want, and prefer, a different DAC, and you have one; nothing wrong with that. There are many good reasons for the choices Ted made with the DS, it is just not the DAC for you.

[Dev]

AL: you are probably asking for the impossible, I am speculating a bit here, but I suspect there are reasons why what you asked for are not possible:

 

!. The FPGA is responsible for clocking/aligning the data stream, hence it cannot be "bypassed", additionally, there would be no volume control without the FPGA.

 

2. The FPGA has limited resources, and PS Audio is already asking it to do a whole lot of processing. It is very likely that it would not be able to accommodate two entire firmware versions at once.

 

3. The D to A stage (or filter if you prefer) requires to be fed DSD 128, so even if one could bypass the FPGA, then one could only send through DSD 128. Since the filter is optimized for DSD 128, it is very likely there would be way too much noise if one sent DSD 64 through to it.

 

Clearly you want, and prefer, a different DAC, and you have one; nothing wrong with that. There are many good reasons for the choices Ted made with the DS, it is just not the DAC for you.

 

 

Excellent post. Whole heatedly agree Barrows.

[mikey8811]

I tried Torreys again and then Yale.

 

I still preferred 1.2.1 and went back to that. I liked the additional weight. It's not as airy sounding and there isn't as much space between the notes and instruments but it has a more musical flow.

[TarnishedEars]

From what I have read here and elsewhere, 1.2.1 is the firmware with the “best” midrange richness. I understand that both Pikes Peak and Yale are inferior to Torreys as far as this midrange attribute is concerned so it is a waste of time to try those. Is this correct?

I'd agree with that assessment. However the idea of not trying the other builds just because somebody said something on the internet seems silly to me. But I like to roll tubes to get the perfect sound. So rolling firmwares can be pretty cool in my book.

[TarnishedEars]

I tried Torreys again and then Yale.

 

I still preferred 1.2.1 and went back to that. I liked the additional weight. It's not as airy sounding and there isn't as much space between the notes and instruments but it has a more musical flow.

I'm torn between the two, but I slightly prefer Torrys because it is more honest, resolving and has slightly better PRaT than does 1.21. 1.21, by contrast seems to have a more romantic quality to it which I really enjoy, as well as a slightly wider soundstage when compared to torrys. But other than those two attributes, Torrys now gets the overall nod overall on my system.

 

FWIW: Toeing my speakers out just smidge with Torrys really helped improve the image on my system.

[TarnishedEars]

FYI - Here is a trick which I highly recommend that other DS users should try with your DS's. Try throwing one of those $1.50 ground lifters on your DS's power cord, and just take a listen. I find that isolating the DS from the utility earth ground really opened-up my soundstage on my DS. Frankly I was lukewarm about the sound of my DS before I stumbled upon this discovery. But now I LOVE it!

 

Now this is probably entirely system dependent. But the noisier your earth ground is, the better than this will work. And since so many power line filters shunt their noise to ground, this can be a means of isolating your DS from all of that noise that your filters have injected into your earth ground.

 

I keep meaning to post this tweak on PS Audio's website, but I've decided to do it here first. There is a bit more to it though since if other it is getting re-grounded via other components, that can sometimes re-inject the noise, and keep this from working. But I have developed a super cheap mod which makes this all unnecessary. However I'm not going to say anything more about it unless some of you also hear this same improvement on your own systems. On mine doing this is like night and day for the DS. And no, I have no hum issues whatsoever, so this is not a ground-loop problem on my system.

 

I also suspect that the biggest reason why the PS Audio regen helps with the sound of the DS is simply because it may add a small degree of ground isolation at RF frequencies. But this method is dirt cheap, and it works like a charm on my setup.

[mikey8811]

Can you provide a link to these ground lifters?

 

Thanks

[audio.bill]

This is an example of what I believe he is referring to: GE Grounding Adapter

[mikey8811]

This is an example of what I believe he is referring to: GE Grounding Adapter

 

 

That's a cheater plug right? Isn't that frowned upon if you are using a good power cord and is there any danger if plugging into a 3 prong outlet?

[audio.bill]

Yes, it's called a cheater plug, 3-wire to 2-wire adapter, or grounding adapter. It effectively disconnects the ground connection at the AC wall plug end of the cord. Ground currents can still be carried between components over other interconnecting cables. It is often debated about the long term safety of such arrangements, so it should be specified that you 'use it at your own risk'. Some say that if you had an electrical fire in such a setup insurance may not cover it since it's not strictly up to code. It's generally believed that there's no significant harm in briefly trying it to see how it sounds or to help diagnose grounding problems, and then you might decide to come up with a more safe long term wiring solution. YMMV applies.

[TarnishedEars]

Yes, I was indeed referring to the so-called "cheater plug" above for purposes of testing whether my idea works in your system or not.

 

I'm not saying that this is necessarily a safe long term arrangement. But since your DS should be grounded via its connection to your preamp or amp anyways, this really shouldn't be terribly unsafe.

 

However I have developed a mod which provides the same sonic improvements as this grounding arrangement, but while still being 100% UL approved. But I'm interested in seeing how many other people hear as big of an improvement from doing this as I do before I take the time to show everyone how to potentially void the warranties on your DS's.

 

The disclaimer: AC voltages can be lethal. So try this at your own risk and expense!!! I warranty nothing, and I take no responsibly if you should somehow manage to electrocute yourself in the process, or fry your DS.

[TarnishedEars]

So am I to take it that none of the other DS owners on this forum are brave enough to try this ultra simple trick and report back as to whether you hear a difference or not in your system?

[westy]

So am I to take it that none of the other DS owners on this forum are brave enough to try this ultra simple trick and report back as to whether you hear a difference or not in your system?

 

I'm using a Synergistic Research Grounding block with all of my components and that includes my PS Direct Stream.

With this item I have noticed a definite improvement in sound quality. Tonight, I will try a cheater plug with just my PS Direct Stream and report back.

[westy]

TarnishedEars,

 

Ok, I lifted the ground and I do think there is a clearer soundstage with a deeper truer bass quality. However, I need to keep testing this before I agree that it does sound better without the ground, but...it just may.

[TarnishedEars]

Thanks Westy.

 

Are any other DS owners willing to try inserting a cheater plug on your DS's and report back? Don't let the ridiculously low price of this tweak fool you into thinking that it can be any good.

[mikey8811]

Is anyone using the TotalDac D1 USB cable with the DS?

 

Was wondering about the nature of the cable compared to a Cardas Clear High Speed which I am currently using.