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Review and Measurements of PS Audio PerfectWave DirectStream DAC

Miska

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We don't know if they meet it. We would need to verify it.

I have one of those devices and at least my unit exceeds the spec... Very useful tool for developing DACs, so many DAC designers have it (I know quite many).

It fits neatly in the middle between my audio analyzer and 200 MHz scope/spectrum analyzer (1 GS/s which has only 8-bit resolution).
 

Frank Dernie

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The best answer you can provide is that below a certain threshold that is hard to pinpoint and varies, the measurements may indicate artifacts that are audible with no measure of how audible. Correlation is not the right word for it.
Quite so.
We don't know what the threshold for audibly indistinguishable is, and we don't have a threshold for audibly acceptable, either.
If I take the hairy-arsed approach to engineering I could point out that many audiophiles enjoy LPs and reel-to-reel tapes to they extent they confidently announce that they are superior to "digital", whatever that means.
This is demonstrably technically absurd so one is left with the question of whether the shortcomings of these media are simply inaudible or if the shortcomings are euphonic.
I have 4 turntables and they all sound different. I have more than 4 DACs and last time I did a careful level matched listening comparison (several years ago) they all sounded the same, or if there were differences they were difficult to be sure of, hence irrelevant.
So I would say, my personal view, is that CD is at least good enough to be in all intents and purposes perfect for listening to music. Anything "better" may be technically interesting, or admirable, but is IMO pointless.
If fairly high levels of distortion and noise ruined musical enjoyment nobody would ever say LP or R2R were superior.
I have done some experiments, about 20 years ago, which showed that adding a bit of noise gave the impression of a bigger stereo image, so for those people for whom spatiality is of importance a noisier source may well be preferred. FWIW the noise added was easily audible before the music started but certainly not percieved as noise once the music started.
 

Stephensank

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I appreciate that advice. I don't mind addressing any technical comment provided because it is another educational opportunity to explain things. I try to keep my answers informative. And any rate, I don't want any counter technical argument left unanswered. Audiophiles deserve to see answers when they exist.

I wish every designer in audio cared about excellence and faithfulness in sound reproduction so I did not have to do this work. But we have lost our way for so long that there has been mad gold rush to build products that no longer consider the word "high fidelity" to have any meaning. By having no third-party scrutiny of their design and execution, combined with false methods of subjective audio listening, they are going south when they should be going north. I don't know any other industry that is so left alone to actually go counter purpose to its stated goal.

I was servicing & selling McIntosh, Nakamichi & Yamaha gear in the early 80's, and would like to voice a concern about your *apparent*(my perception after just a few days of reading this forum) opinion that "measures great must mean sounds great".

Part of the reason that companies like ARC & c-j really gained traction in the 80's was that companies like Yamaha were seemingly of exactly the same bent, i.e., if we make our gear measure great, it must sound great. Anyone who followed Yamaha's model progression in the 1981-1990 period, especially those of us selling it, can tell you with 100% certainty & conviction- Each model year, as the measured performance got better in Yamaha's gear, especially their amps, the sound got proportionately *worse*! By 1985 or so, the prime example was the MX1000/800/600. It's test bench performance exceeded the capabilities of most analysis gear of the time, was flat to 100kHz, drew perfect squarewaves at any power level, but is one of the worst sounding amps of all time, especially if you had spkrs that had good response past 15kHz. In their blind, or more literally *deaf* pursuit of great numbers, and many other makers were doing the same thing with similar results, they had completely ignored considering what would happen with real music, i.e., non-repetitive, complex waveforms. In the MX1000/etc. case, they'd created amps that were so borderline unstable, that actual music at even modest levels, caused transient oscillations that never showed up with sine or squarewaves, but made undeniably irritating & repellant sound.

So, while I applaud your efforts to draw attention to poor measured performance & the possible sonic effects, I fear that you're causing people to fall down the same rabbit hole that Yamaha did in the 80's, assuming great specs means great sound, and buying purely on this basis, as long as they don't hear overtly bad sound from a given thus-selected unit. Add to this the seeming absence of any expert commentary on build quality & component choices relative to long term durability, and I fear you are unintentionally leading people down a path where they're ending up with systems that sound far from great and that require repair or replacement far too soon or often.

The other point is this- People like McGowan are a by-product of the same era I decribed above, and built their "empires" largely as a result of design engineers like those at Yamaha who devoted themselves to the "if it measures perfect, it *must* sound perfect" philosophy, and created gear that sounded mediocre to downright awful. So, how about not repeating the same mistakes, and avoid creating a whole new generation of snake-oil audio salesmen.

It's fine to use measurements to find problems in a design & to find audible issues you might otherwise have missed, but devotion to measurements without balancing it via willingness to do open-minded & thorough *listening* comparisons to gear that is highly praised but measures imperfect is as bad as not measuring at all.
 

solderdude

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It's fine to use measurements to find problems in a design & to find audible issues you might otherwise have missed, but devotion to measurements without balancing it via willingness to do open-minded & thorough *listening* comparisons to gear that is highly praised but measures imperfect is as bad as not measuring at all.

I would endorse listening tests but under controlled and equal conditions.
This is something I have never, ever seen one single sales person do over the last 35 years or so.
 

Stephensank

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I would endorse listening tests but under controlled and equal conditions.
This is something I have never, ever seen one single sales person do over the last 35 years or so.
In the 80's thru mid 90's, when I was still in retail environments, we, as a "high end" dealer(mac, nak, yamaha, c-j, apogee, nothing crazy exotic) in Philadelphia, we did our best to provide every customer as thorough a/b testing between two or more pieces as we were able to in the circumstances.
But I was more referring to, as a design engineer myself, we designers comparing our designs to the best *sounding* competitors' gear we can get hold of, and spending lots of time going back & forth, blind or not, with whole tracks or even a single phrase of a track, a/b'ing our design with theirs, and making damn sure that we're not fooling ourselves with measurements, and getting as many of our friends and, if we can afford it, staff to do the same. It's what I do, every single time, whether it's a ribbon mic, dac, amp or cable.
Could be why I'm so damn tired all the time.
 

BillG

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It's fine to use measurements to find problems in a design & to find audible issues you might otherwise have missed, but devotion to measurements without balancing it via willingness to do open-minded & thorough *listening* comparisons to gear that is highly praised but measures imperfect is as bad as not measuring at all.

On nearly every review I've read here Amir gives his listening impressions. As for something more rigorous, I'd support controlled, double blind, listening tests, but that's it... :oops:
 

AudioSceptic

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It's worse in my house. AC running 6 months a year, forced air hear for 3. Nearby rail and truck traffic. Crazy wife.

The real question is why can a "respected manufacturer" make a $6k dac that measures like a motherboard Realtek chip and get glowing reviews for it?
Because it costs $6k! If it cost $600 with identical performance they would say it's no good.
 

AudioSceptic

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Plenty of love, but I find their aesthetic and machining skills to be a distant second to AR's. Plus small 2" VU vs full 15" wide edge-lit VU on glass... no comparison.

Exactly. To me it's akin to buying a guitar that Jimi Hendrix lit on fire. You could refinish it and repair it back to new... destroying the very reason for having it in the first place - or you could put it in a nice wall mount enclosure and look at it while playing a $500 guitar which would sound much better. I am not at all embarrassed about my gear fetishism - I embrace it entirely. Just because I'm perfectly happy listening to ugly gear, doesn't diminish my desire to look at and potentially own beautiful gear as well. They're completely separate (but still related) interests. I use computers and digital cameras, but I own a number of vintage (1930's era) typewriters and cameras. They're all visually appealing to me, but I wouldn't want to have to actually use them for their original intended purpose. ;)


I do think those look pretty good. I particularly like the fact that they have HIFI versions which are exactly the same except for this critical difference:

That's what I call "knowing your customer." If you don't want pointless audiophile accoutrements then we've got your speaker, if you want to pay us extra to say that you have them... we've got your speaker too. :D
The Tim de P involvement I get, as he's got a serious rep, but using AQ cables actually puts me off.
 

pozz

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Anyone who followed Yamaha's model progression in the 1981-1990 period, especially those of us selling it, can tell you with 100% certainty & conviction- Each model year, as the measured performance got better in Yamaha's gear, especially their amps, the sound got proportionately *worse*! By 1985 or so, the prime example was the MX1000/800/600. It's test bench performance exceeded the capabilities of most analysis gear of the time, was flat to 100kHz, drew perfect squarewaves at any power level, but is one of the worst sounding amps of all time, especially if you had spkrs that had good response past 15kHz. In their blind, or more literally *deaf* pursuit of great numbers, and many other makers were doing the same thing with similar results, they had completely ignored considering what would happen with real music, i.e., non-repetitive, complex waveforms. In the MX1000/etc. case, they'd created amps that were so borderline unstable, that actual music at even modest levels, caused transient oscillations that never showed up with sine or squarewaves, but made undeniably irritating & repellant sound.
Sounds like we should get hold of one. Instability is something that would show in Amir's amp tests.
 

Rja4000

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Each model year, as the measured performance got better in Yamaha's gear, especially their amps, the sound got proportionately *worse*!
I remember those times, and, indeed, I had a similar experience (although not with Yamaha).
Most pristine-speched Japanese integrated were indeed sounding dull compared to some UK brands (or even US or other Japenese).
I suspect power amps specs based on SNR, THD and crosstalk @1kHz and, even, standard SMPTE or DIN IMD with a resistive load don't give a clear (or full) picture of the sonic performance. More things are related to the load, probably, as well as stability and other things (a multitone test seems more relevant, as an example).

That doesn't mean that measurements are irrelevant. Just that it's important to always challenge what's measured and to cross-relate that with proper listening tests.

The later is a bit controversial here, just because it currently involves only one person (without raising any doubt about Amir's ability and honesty in those!)
How could we improve that?

As an example: is there a way to record some relevant output material, share it and ABX it by the community?
Can also be selected few.

Just want to add: as far as I can share doubts about measurement of things as complex as a power amp -which has to face very variable and complex loads and where, due to costs, compromises usually have to be made-, I'm pretty sure that doesn't apply to DAC, ADC, line-level pre-amps or even headphone amps.
 
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AudioSceptic

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I think that many of those who lived through the vinyl and tape (8 track, cassette, R2R) era recognized greatness when digital music arrived, first as DAT followed by LaserDisc, CD and lossless digital.
Actually, DAT came after CD and CD after LaserDisc. CD and DAT were always lossless.
LaserDisc 1978
CD 1982
DAT 1987
Or by DAT did you mean digital tape recording in general?
 

greenpsycho

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I have a bit of an odd question pertaining to the PS Audio DS DAC - I have the Junior, and I always liked it, while at the same time I realize it may not be "hi fidelity" but at the time I purchased it, it was one of few out there with networked roon integration and all the other features I needed.

Anyways, after this review, I picked up a balanced Grace SDAC for comparison. I volume matched them and am using an XLR switcher fed into my headamp (bryston BHA-1). This allowed me to seamlessly switch between the two to really call out the differences. The one odd thing I noticed is that the PS Audio dac is slow. Yes, its delayed compared to the grace dac (not much, but some), but its also playing at a slightly slower speed. Its not always apparent, but I noticed it on a track by Daft Punk and I'm honestly a bit stumped. It was slight, but definitely there and noticeable in parts with fast beats. I wish I had a way to measure or record what I'm hearing, but I don't

Does anyone have any thoughts or clues as to why this might happen?
 

Krunok

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Each model year, as the measured performance got better in Yamaha's gear, especially their amps, the sound got proportionately *worse*! By 1985 or so, the prime example was the MX1000/800/600. It's test bench performance exceeded the capabilities of most analysis gear of the time, was flat to 100kHz, drew perfect squarewaves at any power level, but is one of the worst sounding amps of all time, especially if you had spkrs that had good response past 15kHz. In their blind, or more literally *deaf* pursuit of great numbers, and many other makers were doing the same thing with similar results, they had completely ignored considering what would happen with real music, i.e., non-repetitive, complex waveforms. In the MX1000/etc. case, they'd created amps that were so borderline unstable, that actual music at even modest levels, caused transient oscillations that never showed up with sine or squarewaves, but made undeniably irritating & repellant sound.

Sure, those things happened, but I don't remember a single example of unstability in amps designed in last 20 years, so I don't think that is the reason to claim that measurement are not giving the full picture. Btw, I believe 20 tone IMD test (or something similar) would reveal unstability issue.
 

solderdude

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Yes, its delayed compared to the grace dac (not much, but some)

A bit more latency is possible. You won't notice this in normal usage. It will only be obvious when both DACs are playing the exact same signal.
It is probably because of the PCM to DSD conversion (needs buffering) and who knows how much data is buffered.

but its also playing at a slightly slower speed.

That would mean it would need a lot of memory and for a long song grace DAC would have finished and the PS later, later than the latency.

Judging from the 1kHz being extremely close to 1kHz (999.97Hz) it only plays 0.03% too slow. I don't think that such would be audible.

When you like how the PS sounds and works then I see no need to replace it.
The Jr doesn't have the transformers so may even perform better.
 

AudioSceptic

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Exactly! I for one would love to shop for gear in a world where the manufacturing cost was the sole variable - in other words, where I could reasonably expect that any piece of gear would perform near the optimum levels allowed. I think most consumers would like a product costing multiples of a cheaper device's price to be at least a small amount better in every way. Most would even understand that there would be diminishing returns in that pursuit.

There won't ever be a time where a $6000 DAC performs 20X better than a $300 DAC - especially if the $300 DAC is already at a level where it's audibly transparent to the source. However hopefully, along with the beautiful chassis, large, clear display panel, and great customer service - it is also engineered to have at least slightly better measurements. Even if we assume that the $300 version has attained such amazing levels that it simply can't be improved upon with current technologies - then at least make sure it measures 100% as well as the cheaper one. Let the consumer decide if the premium is worth it for appearance alone (you might be surprised at how many do)!

Companies like Matrix Audio, Okto Research and others have shown that it's possible to make objectively superior and subjectively appealing components. Similarly the SMSL, Topping, Khadas, etc. offerings show that by shedding the majority of the aesthetic bits (and trimming a few features)... fantastic performance is attainable within a very modest budget as well. All while leaving plenty of room for companies and individuals like @March Audio to provide products which reside somewhere in the middle.
Well said. Remember that the March DAC1 actually uses the Khadas, so the added value is mostly in the enclosure.
 

AudioSceptic

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You can never quote Peter Aczel too mant times! I still regularly read the old Audio Critic magazines and it is really both very sad and telling that his general observations could be written today and be just as true. And then audiophiles wonder why the hobby is dismissed as a bubble of snake oil by so many people.
For anyone who doesn't already know, you can download a number of 'Audio Critic' PDFs from <http://www.biline.ca/audio_critic/audio_critic_down.htm>
 

greenpsycho

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A bit more latency is possible. You won't notice this in normal usage. It will only be obvious when both DACs are playing the exact same signal.
It is probably because of the PCM to DSD conversion (needs buffering) and who knows how much data is buffered.



That would mean it would need a lot of memory and for a long song grace DAC would have finished and the PS later, later than the latency.

Judging from the 1kHz being extremely close to 1kHz (999.97Hz) it only plays 0.03% too slow. I don't think that such would be audible.

When you like how the PS sounds and works then I see no need to replace it.
The Jr doesn't have the transformers so may even perform better.
Right - to clarify, the same signal is being fed to both via grouped zones on Roon. Latency isn't super noticeable on vocal stuff, but with high tempo tracks (daft punk) its noticeable. However, the play rate (I need another term for this) is definitely slower - it doesn't seem to effect tonality as speeding up/down a track normally would, but the rate at which the drums hit is definitely there, as if the tempo of the song has changed. I might try to rig up an ADC to see if I can record what I'm hearing.
 

pozz

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The one odd thing I noticed is that the PS Audio dac is slow. Yes, its delayed compared to the grace dac (not much, but some), but its also playing at a slightly slower speed. Its not always apparent, but I noticed it on a track by Daft Punk and I'm honestly a bit stumped. It was slight, but definitely there and noticeable in parts with fast beats. I wish I had a way to measure or record what I'm hearing, but I don't.
That would show up even in a phone recording. If you can upload one of those it's easy to test.
 

Soniclife

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Right - to clarify, the same signal is being fed to both via grouped zones on Roon. Latency isn't super noticeable on vocal stuff, but with high tempo tracks (daft punk) its noticeable. However, the play rate (I need another term for this) is definitely slower - it doesn't seem to effect tonality as speeding up/down a track normally would, but the rate at which the drums hit is definitely there, as if the tempo of the song has changed. I might try to rig up an ADC to see if I can record what I'm hearing.
Try doing PCM to DSD conversion in roon and see what happens.
 

Timbo2

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Exactly, that's how it was for me after almost 40 years of wrestling with all the physical, technical, and convenience issues with vinyl. To this day I still can't understand the fad of vinyl resurgence. BLAH.. LOL

I know we've discussed this before, but I'm convinced part of it that vinyl doesn't play suffer from the "loudness wars" the way CD and streaming does. People hear actual dynamic range on vinyl or less compression and attribute it to the media and not the mastering.
 
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