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Review and Measurements of PS Audio PerfectWave DirectStream DAC

I still struggle to understand why anyone would pay 6k for a DAC and try and pretend it was about SQ. I can get why you might buy such a product if it offers drop dead gorgeous design or as a statement (even if it's not what I'd do) but in terms of SQ why would you spend that much on a part of the audio chain where fully transparent performance costs peanuts? If you want to colour the sound then use EQ or DSP.

And how can anyone claim that developing a product in a big box with transformers costing thousands of dollars is good engineering? Good engineering is making a $9 DAC dongle with superb performance.
these are snake oil vendors. i struggle to understand how a former RSDE could, in good faith, say that he can change how a media streamer sounds by mucking around with ethernet switching. frankly, i suspect he is either knowingly lying through his teeth to separate the gullible from their money, or he really believes that this is true. in the former, this is criminal. in the latter case, he needs help.

i have no idea why i suddenly feel so strongly about this, but the above is, i believe, quite true.
 
By the way, I wrote a much more detailed article on my measurements for Widescreen Review Magazine. I suspect it is published by now so when I get a chance, I will upload it here (have to reformat the pictures for web).
Will you update your page with measurement description?
Quite a few tests are new or modified and you have the new AP...
 
I still struggle to understand why anyone would pay 6k for a DAC and try and pretend it was about SQ. I can get why you might buy such a product if it offers drop dead gorgeous design or as a statement (even if it's not what I'd do) but in terms of SQ why would you spend that much on a part of the audio chain where fully transparent performance costs peanuts? If you want to colour the sound then use EQ or DSP.

And how can anyone claim that developing a product in a big box with transformers costing thousands of dollars is good engineering? Good engineering is making a $9 DAC dongle with superb performance.
And don't forget that $6k is low-end compared with a lot of stuff out there. Who is buying it, and why?
 
There is but again, I am confident they mean THD+N. Measuring them separately is much harder (requires spectrum analysis).
Thanks.

Edit: isn't N just random noise in the absence of signal and you just have to decide which frequency to measure at?
 
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Multitone.
I thought dashboard was 48kHz.
And do you apply averaging?
The multitone is 192 kHz sampling as I stated. Just shut down the machine so don't remember the FFT. I suspect it too is 256k Points.

Dashboard averaging is 3. J-test is 8. Multitone is probably similar. Filter tests use 16 times averaging since the test signal is noise.
 
The multitone is 192 kHz sampling as I stated. Just shut down the machine so don't remember the FFT. I suspect it too is 256k Points.

Dashboard averaging is 3. J-test is 8. Multitone is probably similar. Filter tests use 16 times averaging since the test signal is noise.
And IMD vs level?
 
Dashboard sampling rate is usually 44.1 and is indicated in green at the bottom of those measurements. When I change output devices, AP software changes that to 48 kHz sometimes as is the case here. It usually makes next to no difference unless a DAC only has a good clock for 44.1 or 48 which is rare.
 
Dashboard sampling rate is usually 44.1 and is indicated in green at the bottom of those measurements. When I change output devices, AP software changes that to 48 kHz sometimes as is the case here. It usually makes next to no difference unless a DAC only has a good clock for 44.1 or 48 which is rare.
I remember once you explained that some DACs are optimized for 44k and therefore you did most tests at 48k
 
There is no FFT there. Sample rate is 48 kHz from memory. I just shut down my machine so can't look....
? No FFT ?
There should be one behind the scene?

Thanks for explanations!
Would be great if you could publish those details.
Being able to reproduce results is important (for us learning) :)
 
I remember once you explained that some DACs are optimized for 44k and therefore you did most tests at 48k
Correct. That was early days when were testing dirt cheap, ebay special DACs. I have not seen that since. Still, I am leaving my tests as a mix of 44 and 48 kHz to catch it if it happens.
 
? No FFT ?
There should be one behind the scene?
The analyzer hardware and software has a dedicated IMD and THD+N analyzer. I am pretty sure neither uses FFT but instead, a bandpass filter. Fundamental frequencies are dialed out and what is left is THD+N or IMD.

There is an FFT based THD analyzer too which I have post occasionally (e.g. in Benchmark tests). But that is not the standard meter.
 
The analyzer hardware and software has a dedicated IMD and THD+N analyzer. I am pretty sure neither uses FFT but instead, a bandpass filter. Fundamental frequencies are dialed out and what is left is THD+N or IMD.

There is an FFT based THD analyzer too which I have post occasionally (e.g. in Benchmark tests). But that is not the standard meter.
IMD is actually IMD+N, for sure.
So analog notch + amp to raise level + SOTA ADC
It's easier to understand the price of this beast...
 
I owned one of these for over a year and I hated the sound. It was very bright sounding. I spoke with the company and they kept telling me it needed more "burn in" time. Load of crapola. In the end, I had to get ride of it.
 
PS Audio PerfectWave DirectStream DAC $ 6000

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Focusrite Solo Gen3 $ 110 or € 110

https://www.audiosciencereview.com/...nal-thoughts-of-the-focusrite-solo-gen3.9101/

thd.png
 
I have addressed all of that extensively in the past. There are entire threads on it. See: https://www.audiosciencereview.com/...ts-of-schiit-yggdrasil-dac-inconsistent.3812/

Remember, Schiit advertises on their site and they have built a reputation of saying Schiit is the best audio gear there is. So of course they try go create some doubt. But it is without merit. I have also caught Marv in the past using USB cleaners to hide jitter issues with Schiit gear without being clear about that.

BTW, the link referenced was with my old analyzer. All the measurements you see now and across the last 175+ DACs are with my new, state-of-the-art APx555 analyzer I purchased in June of 2018: https://www.audiosciencereview.com/...s-a-new-audio-precision-analyzer-apx555.3442/

They are using toy-level analyzers compared to what I use.

My analyzer just came out of warranty. Yet is accuracy is the same as my previous 20+ year old AP analyzer. These are precision electronic components and simply do not degrade with respect to their application. I asked AP how often I need to calibrate the new one and their answer was basically never unless there were legal liability in some measurement.

If you disagree, tell me how often you calibrate your DAC! The analyzer is nothing but a DAC/signal generator and Analog to Digital Converter.

Note that there should be no dispute whatsoever regarding the test results of PS Audio PerfectWave DirectStream DAC. The reason was in the review. They publish the distortion spec on their website:

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You see that line that says "THD&IM" that is less than 0.03%? This is what I got:
View attachment 34380

So my measurements actually show lower distortion than their own!

People did not pay attention because there was no comparative data. Here, we have that. We convert THD+N to dB which becomes SINAD. PS Audio's 0.03% THD+N would translate into SINAD of just 70 dB. That would have made the DS DAC the 7th worst DAC I have ever measured, behind a $20 phone dongle (VE)!!!

My measurements were also better than those conducted by stereophile.

And confirmed indirectly by showing distortions that even good transformers could create.

There just isn't an argument here regarding test results. I welcome PS Audio to show us Audio Precision analyzer test results that are different. As it is, we don't even know if they have a proper audio analyzer given the vague THD number above and no screenshots whatsoever.

Note that the pressure from my tests caused Schiit to purchase the same analyzer and start to build better products and release same kind of test documentation that I do. So whatever argument SBAF people had was just that: empty arguments.

I hope PS Audio does the same and doesn't just go by some unscientific impression of sound by a couple of people to build and sell $6000 DACs. You can't design seriously good audio gear without proper measurements. They are certainly big enough to be able to afford a proper analyzer.

If they never publish such measurements, then you know to stay away from them. That would be my recommendation.
Thank you for the clarification. You didn't needed to and you did. Very much appreciated.
 
One thing that I am thinking about. And mind that I don't even have a 10 'th of the knowledge you guys/girls have. Couldn't he have designed it with a purpose? Maybe he deliberately doesn't want good measurements. But they were looking for a kind of sound.
I have been listening months now with a Grace Design m902 to music on the computer through headphones. I thought let's switch again and connect the headphone to the computer. And the music was much more spacial, a bit more highs a lot less details and less clear what someone was singing. I let it hear to my mom a couple of months ago and she liked it more. And yes I agree that it suits some music better than my Grace Design (which costed me around 1700€ I think).
So maybe they designed this dac with a philosophy and for it to be perceived better to the ear than some better measurements dac for some people who like that sound.
Because after all measurements are just measurements. One thing is clear. Either my Dac measures better or either my computer. Both bring something else to the table.
I agree that the prices are ridiculous. But I don't know if it wasn't intentional to have a product with these measurements
 
You're right. I misread that: THD&IM. So each, separately, not together. That still excludes N, though. How do get THD + N? Is it simply the worst of the 2, or is there a formula for combining them?
You can have THD without N, though I agree with Amir they probably mean THD+N.

THD is adding together all the harmonics. Actually a RMS value of all harmonics compared to the input signal. To add N, the way it is done is taking the value of the input signal, notching out the input signal and measuring the value of what is left vs the input signal. So you are including all harmonics plus the noise. Sometimes noise is the biggest item, so THD is swamped. More commonly THD is the largest part with a little contribution by N.
 
This leads to a situation where I don't know what to believe anymore. Because I don't know all these technical stuff.

No problem. But this is high school science - i.e. the importance of the experiment procedure. The full details of setup and procedure can sometimes explain results and conclusions.

So without the full details of setup and procedure, there is always this question mark. As mentioned, the devil is usually in the details.

So it would be great if Amir would address these points.

Amir already said he cannot write a bible for every review and that is 100% understandable.

It is POSSIBLE that if Amir included details and photos of his setup of the DirectStream DAC measurements that it's designer could pick holes in his testing setup and method... in the same way holes have been shown by Amir's measurements in the DAC's performance...

And now imagine this was done for every DAC Amir has measured?
 
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