Review and Measurements of PS Audio PerfectWave DirectStream DAC

[JBNY]

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We have the low frequency spikes that we saw in the noise floor analysis. Outside of that, the spectrum is very clean and just compromises of noise. That noise floor is high due to poor dynamic range of the unit. I worried that it was hiding something. I increased FFT depth and averaging but nothing came out of that.

Next, I hooked up Toslink from my APx555 analyzer. It too showed identical output to above. I then turned on jitter on Toslink and no matter what I did with sine wave jitter, nothing would disturb the DAC's output. Or its ability to lock on it. So this claim regarding input independence and ignoring input jitter is correct. Nicely done.

Why is -130db considered a "high noise floor". -150db is as low as you can measure. Even at -85db we are not going to be able to hear anything.

 

[amirm]

Amir, can you provide any guidance on the value of PS Audio's signature AC generator on audio quality of downstream equipment (especially but not only amps)? @amirm

I have one of their first generation units that I plan to test "one of these days."

For now, I did some limited testing using a high-performance headphone amp. I used my lab AC generator and dialed its distortion way up and it made no difference whatsoever on measured performance of the amplifier.

 

[amirm]

Why is -130db considered a "high noise floor". -150db is as low as you can measure. Even at -85db we are not going to be able to hear anything.

There is 55 dB of "FFT gain" in that graph. So real noise level is 130-55 = 75 dB or so. The only values you can read accurately in those graphs are the actual spikes, not the noise floor

 

[MediumRare]

I have one of their first generation units that I plan to test "one of these days."

For now, I did some limited testing using a high-performance headphone amp. I used my lab AC generator and dialed its distortion way up and it made no difference whatsoever on measured performance of the amplifier.

I'd be fascinated to see you try to damage the power curve (frequency, clipping, amplitude, etc.) and then see 1. The measured effect on output of an amp and 2. The ability of the PerfectWave to deal with the same problem.

I suppose that, just like your USB cable test, your testing on different amps (or CD players, whatever) might show a poorly designed unit might even benefit.

 

[pozz]

Thank you Amir, kind of expected poor results but this was far worse than expected, and kudos to the owner sending it in. Would really like to see tests of other costly DACs from DCS, Bricasti, Berkeley and so on. But I guess the upside for an owner of an expensive DAC is negligible and the downside massive (value-and pride of ownership wise)

There's a review from last year of the Berkeley Alpha DAC 1.

 

[amirm]

I'd be fascinated to see you try to damage the power curve (frequency, clipping, amplitude, etc.) and then see 1. The measured effect on output of an amp and 2. The ability of the PerfectWave to deal with the same problem.

You mean do it with this DAC? If so, I don't think it will impact it. By itself it has such a high noise floor that won't be revealing. But sure, I can try it.

 

[majingotan]

This makes Schiit multibit look like they engineer better though obviously still schiity

 

[amirm]

Thank you Amir, kind of expected poor results but this was far worse than expected, and kudos to the owner sending it in. Would really like to see tests of other costly DACs from DCS, Bricasti, Berkeley and so on. But I guess the upside for an owner of an expensive DAC is negligible and the downside massive (value-and pride of ownership wise)

I am trying to get more expensive DACs. So far we have tested TotalDAC and Berkeley. A Naim DAC is coming from europe. So we are getting some coverage.

 

[MediumRare]

You mean do it with this DAC? If so, I don't think it will impact it. By itself it has such a high noise floor that won't be revealing. But sure, I can try it.

Actually, I was thinking more with respect to the benefit of the PerfectWave Power plant (like this one https://www.psaudio.com/perfectwave-p5-power-plant/) on other equipment you have tested (your reference amps for example), but with an intentionally damaged AC source. Did that clarify what I meant?

 

[daftcombo]

Measuring a dCS would definitely be nice.
By the way, aren't there shops where you can rent hi-end or pro audio devices for a day? I know it exists in Canada. That would perhaps be cheaper than shipping such machines.

 

[daftcombo]

For headphone I used DROP + MRSPEAKERS ETHER CX with its XLR connection to THX 887 amp.

OT: could you tell us more about these phones?

 

[Matias]

Wow, and that is running the latest firmware version after several updates since it was released.

 

[majingotan]

I am trying to get more expensive DACs. So far we have tested TotalDAC and Berkeley. A Naim DAC is coming from europe. So we are getting some coverage.

Really curious to see how Chord DAVE measures as well as the Linn Klimax DSM that uses an off-the-shelf AK4497EQ DAC chip

 

[VintageFlanker]

Dear @amirm ,

Would you please stop destroying every audiophile myths and reputation of such respectable companies?!...
Schiit, Audio-GD, Totaldac...and now PS Audio... Looks like people will somehow talk a bit about this.

Oh, wait... Being crazy, I changed my mind. Please never stop doing this!

 

[Cortes]

Paul's smooth talking, story telling, grandfatherly demeanor can't save him now...

I think the opposite. Paul won't lose many feathers in this fight because:

1. Amir is not using the latest firmware. That's enough ammunition to let old fox Paul to kill the review.
2. Much of the audiophile community is immune to these scientific reviews. I saw that when I put some links
in audiogon about the horrible performance of a Ayre dac, and people laughed at me.

 

[Cortes]

ah, BTW this is another 'pivotal' review of ASR. It has the potential to reach the influence of epical failures, like the Shiit or TotalDaC dacs.

 

[speedy]

I think the opposite. Paul won't lose many feathers in this fight because:

1. Amir is not using the latest firmware. That's enough ammunition to let old fox Paul to kill the review.

What firmware is currently available that is newer than what Amir is using?

 

[w1000i]

Really curious to see how Chord DAVE measures as well as the Linn Klimax DSM that uses an off-the-shelf AK4497EQ DAC chip

DAVE could reach APx555 limit.

 

[w1000i]

I think the opposite. Paul won't lose many feathers in this fight because:

1. Amir is not using the latest firmware. That's enough ammunition to let old fox Paul to kill the review.
2. Much of the audiophile community is immune to these scientific reviews. I saw that when I put some links
in audiogon about the horrible performance of a Ayre dac, and people laughed at me.

If you like the sound is something else but performance wise seems off. I hope @amirm double check the firmware but even if not the latest why it perform so bad.

 

[Cortes]

What firmware is currently available that is newer than what Amir is using?

I believe is not mentioned (so enough...).

The firmware thing is clompletely key in the business model of DirectStream DAC. They have been able to sell the same hardare during many, many years through giving away for free continuous updates of the firmware. Every time there is a new firmware the general comment in all the audophile forums is that now we have a brand new DAC much better than the previous and for free. So, really it's a key part on their way the make money.