PS Audio DirectStream DAC Mk.2 measurements

[amirm]

Thanks for posting that. We an infer SINAD easily from that graph:

The third harmonic is at -68 dB. So that easily sets SINAD's base case value at that (noise and other harmonics would derate it more). The previous version actually had lower distortion:

The highest peak was second harmonic in that at around -78 dB. In other words, distortion has jumped some 10 dB with the new firmware!

Noise in the old version seems to be rising above 30 kHz. So they lowered what you had zero chance of hearing, and traded it for in-band distortion that could be audible.

Amazing that they are looking at measurements but not paying attention to what is important: non-linearities of this DAC.

 

[Ricardus]

In the video announcing the update Paul actually shows some AP results:

Of course they aren't real screen grabs but rather a shaky video filming a computer monitor screen. Also love how the y-axis on the "improved" measurements is not shown.

I've come to the conclusion that Ted Smith really doesn't know what he is doing. It is possible to design a well performing DAC that uses a FPGA, even one that upsamples to high rate DSD like the Ted Smith's PS Audio DACs. See below for some examples.

Meitner MA3 Integrated D/A processor

www.stereophile.com

EMM Labs DV2 D/A processor

For years, I've attended audio shows at which the Canadian company EMM Labs, either on its own or in conjunction with Kimber Kable and IsoMike, has displayed some of the grandest, most impressive-sounding multichannel systems I've ever heard. When everything was aligned properly, as it was at...

www.stereophile.com

Clearly Ted is not capable of doing the same.

Michael

This video is of course a promotional propaganda piece, but he's basically lying by omission in the video. He's showing you the left part of the noise band, which certainly looks more like this (see attached DSD pic) if you were to expand the frequency axis for more bandwidth. And then he's showing the noise no longer existing in the bandwidth shown. Fair enough. That's all true. And noise shaping it WAY out to higher frequencies is fine in the case of a DAC. As opposed to DSD files he sells, which are gigantic and mostly storing the ultrasonic noise.

I also wonder how he's measuring that noise and coming up with the 30dB number. I'm sure there's some obfuscation involved.

But why do any of this in the first place? So he can continue to push the lie that DSD "sounds better" and try to sell more of his DSD recordings from his record label.

 

[jkr]

We have been upgrading the transformers in both the MK1 and MK2 to custom built nickel core units. The stock MK2 transformers actually roll off the high frequency a good bit and do not output the claimed 4v. It's down -0.7dB at 20khz. and only puts out 3.79v.
Anyway over the last month we have upgraded many MK2's. The build quality is horrendous. One even had the mini ribbon connector glued shut.
We ended up having to offer to fix these defects as we don’t like sending units back half baked.
We re-route the WiFi antenna Cable, Repair the input chassis grounding and fix any hardware issues (stripped wrong screws etc). We even found PC board standoffs 1 turn out loose

I wonder if they have a production manager?


This defect shows that the i2s inputs chassis grounding spring is stuck behind the plastic insulator making it inoperable. The inputs end up with no chassis ground.

Top view

This shows the mis-aligned paint mask keeping all inputs from being chassis grounded. Note the grounding springs are insulated by the paint. The only way to fix this is to scrape the paint away.

This show the RF shielding fingers not install properly. Most all units had most of them missing or none at all.

This shows how we fix the i2s grounding issue. Note now the chassis grounding spring can make contact with the chassis.

We remove the insulator and cut the right side down so the grounding spring will clear. Note the cut line.

After the cut

We made PS Audio aware of these issues back in March. They still have been building them this way.
I think there are allot of unhappy owners now that I exposed these issues on their forum where they were deleted the next day and then suspended my account.

 

[voodooless]

I really don't understand why anyone would bother? Just send the junk back. It's not that the thing will suddenly perform better than a $90 DAC even after all these painstaking mods...

 

[Galliardist]

Thanks for posting that. We an infer SINAD easily from that graph:

View attachment 304034

The third harmonic is at -68 dB. So that easily sets SINAD's base case value at that (noise and other harmonics would derate it more). The previous version actually had lower distortion:

View attachment 304038

The highest peak was second harmonic in that at around -78 dB. In other words, distortion has jumped some 10 dB with the new firmware!

Noise in the old version seems to be rising above 30 kHz. So they lowered what you had zero chance of hearing, and traded it for in-band distortion that could be audible.

Amazing that they are looking at measurements but not paying attention to what is important: non-linearities of this DAC.

What needs to be remembered is that the different firmware versions for this DAC can be stored and switched between, what they meant by
"STORE AND INSTALL UP TO 10 FIRMWARE MOUNTAINTOPS" in the promotional blurb
... whatever a "mountaintop" means. But it implies that you'll want to switch between the different versions they release, so they expect each to sound different, I guess, and that updates are not about fixing issues at all.

 

[mdsimon2]

I think there are allot of unhappy owners now that I exposed these issues on their forum where they were deleted the next day and then suspended my account.

You definitely flew too close to the sun. Although I am not sure I fully understand the logic of starting drama with the company when you have a business modifying PS Audio DACs. Still, I personally appreciate the honesty.

Michael

 

[jkr]

You definitely flew too close to the sun. Although I am not sure I fully understand the logic of starting drama with the company when you have a business modifying PS Audio DACs. Still, I personally appreciate the honesty.

Michael

I feel the owners of this DAC should know the truth no matter the cost. They should have the option to have PS Audio fix it. After all it's not a cheap DAC.
Yes. I thought about the outcome however I feel better about doing the right thing regardless of the money involved. PS Audio never endorsed our upgrades anyway.

 

[Ricardus]

Unfortunately he deletes or blocks anyone who speaks truth to his BS. I can no longer comment under his youtube videos.

 

[kevin1969]

I feel the owners of this DAC should know the truth no matter the cost. They should have the option to have PS Audio fix it. After all it's not a cheap DAC.
Yes. I thought about the outcome however I feel better about doing the right thing regardless of the money involved. PS Audio never endorsed our upgrades anyway.

I've watched all of your posts over at the PS audio forum and found them very fascinating, but I could never understand why anybody would accept the quality and problems that come with the price tag of their products but good for you for offering people a solution.

 

[Billy Budapest]

Below, Another rave review for this dac, what are we missing??

PS Audio DirectStream DAC 2 USB DAC

It's arguable that the best high-end DACs all feature custom upsampling and conversion architectures – nothing 'off the shelf'! PS Audio has been part of the club for a decade... All good things come to an end, although in the world of digital hi-fi sometimes that end comes around pretty quickly.

www.hifinews.com

Advertising dollars, that’s what we are missing.

 

[Ricardus]

The test results get worse and the reviews get better!

 

[DonR]

The test results get worse and the reviews get better!

"The louder they talked about its musicality, the faster we counted the test results." - Apologies to Emerson

 

[mdsimon2]

The reports on the new "Massive" upgrade are hilarious -> https://forum.psaudio.com/t/directstream-dac-mk2-mountaintop-mount-massive/34549/202.

Michael

 

[kevin1969]

The reports on the new "Massive" upgrade are hilarious -> https://forum.psaudio.com/t/directstream-dac-mk2-mountaintop-mount-massive/34549/202.

Michael

Things are going downhill pretty fast over there with all the complaints about noise. I certainly wouldn't mind donating to the cause of getting one of their unhappy customers DACs into Amir's hands for testing and then have JKR perform updates to it and then remeasure it.

 

[Galliardist]

It just amazes me that they have a DAC guru with a decade's experience with DSD conversion software, that couldn't get the noise shaping right on this new DAC first time. Obviously, his equivalent at Marantz and Mola Mola, and others, got that bit right first go. Still, I'd guess that if manufacture is also bad, that no amount of new software is going to fix some of these.

The people in that forum also seem to be obsessed by fuses. I do hope they aren't breaking warranty by swapping goodness knows what into their new DACs, because they may just need it!

 

[kevin1969]

It just amazes me that they have a DAC guru with a decade's experience with DSD conversion software, that couldn't get the noise shaping right on this new DAC first time.

 

[jkr]

Things are going downhill pretty fast over there with all the complaints about noise. I certainly wouldn't mind donating to the cause of getting one of their unhappy customers DACs into Amir's hands for testing and then have JKR perform updates to it and then remeasure it.

Unfortunately, our custom nickel transformer upgrade did nothing to help the final measurements as the noise issue is caused by circuits / SDM / software before the transformers. Fixing the input grounding may help measurements if performed in a noisy environment. Fortunately, our transformers do make a difference in the overall sound quality as they get out of the way unlike the factory Edcor's wired in an unconventional way. The secondaries are wired in series using the junction as common. This gives them a 1:2 ratio (almost) to help give it more output gain however the resulting large winding results in early high frequency roll off, more output attenuation and a large phase error. Also, the iron core doesn't help in the distortion area.

 

[kevin1969]

Unfortunately, our custom nickel transformer upgrade did nothing to help the final measurements as the noise issue is caused by circuits / SDM / software before the transformers. Fixing the input grounding may help measurements if performed in a noisy environment. Fortunately, our transformers do make a difference in the overall sound quality as they get out of the way unlike the factory Edcor's wired in an unconventional way. The secondaries are wired in series using the junction as common. This gives them a 1:2 ratio (almost) to help give it more output gain however the resulting large winding results in early high frequency roll off, more output attenuation and a large phase error. Also, the iron core doesn't help in the distortion area.

I'll have to take your word for it because I have no idea what you just said But one thing I'm wondering is why people on the forum are reporting more issues with the DAC hooked directly up to an amp but not a preamp?

 

[Ricardus]

It just amazes me that they have a DAC guru with a decade's experience with DSD conversion software, that couldn't get the noise shaping right on this new DAC first time.

Did he get it wrong, or did he code it originally for a lower DSD bit rate? And in the updates for a higher bit rate? This way with the higher bit rates he could noise-shape the noise further out into the "newer" higher bandwidth.

Paul was very slippery in his update video. He doesn't like talking about the noise inherent to DSD, and in his pics he only showed the left hand part of the ultrasonic noise, and then showed how it was no longer in the 2nd pic by showing only a limited part of the frequency spectrum.

 

[amirm]

Things are going downhill pretty fast over there with all the complaints about noise. I certainly wouldn't mind donating to the cause of getting one of their unhappy customers DACs into Amir's hands for testing and then have JKR perform updates to it and then remeasure it.

They have money back guarantee. If you want to buy one, have me test it and return if it doesn't perform as well as our top of the line DACs, we can do it that way.