Review and Measurements of PS Audio PerfectWave DirectStream DAC

[617]

How good is your storytelling?

DMM? Direct metal mastering?

Digital Multimeter. I'm no Paul McGowan but I went to art school which helps.

 

[AudioSceptic]

I can't really advise on that - neither I know what DMM is nor I know how old are you to estimate the risks of switching the career.

I have one too, but it's a cheap one, not a Fluke or Keysight (clue!).

 

[Blumlein 88]

Digital Multimeter. I'm no Paul McGowan but I went to art school which helps.

Yep digital multi meter. You can even buy one which includes a scope.

For the old school the sales pitch might work better if you go with a VTVM (Vacuum Tube Volt-ohm Meter).

 

[Krunok]

Digital Multimeter. I'm no Paul McGowan but I went to art school which helps.

Oh, I have a Fluke DMM but I mostly use it to repair some home devices, like washing machine etc.

 

[HammerSandwich]

Only if you crank horns to 120dB+ (which you won't) and you have less than 30dB of noise in your room (which you don't).

I think you've assumed well-matched components with good gain staging, etc. That's not always the case.

Suppose a system with DAC -> power amp -> speakers. There is no analog attenuation in the system. The DAC has 4Vrms output & -90dBFS noise. Amp has insignificant noise but 29dB gain. Speakers give 104dB @ 0dBW. What's the SPL of amplified DAC noise at 1M?

I'm not claiming this scenario is common. Nor ideal. Nor impossible to resolve without replacing the DAC. But I'm pretty sure it is possible for someone to assemble such a system. And that person probably would have been happier with a DAC that has an H2-limited, 90dB SINAD but -120dBFS noise.

 

[Krunok]

I think you've assumed well-matched components with good gain staging, etc. That's not always the case.

Suppose a system with DAC -> power amp -> speakers. There is no analog attenuation in the system. The DAC has 4Vrms output & -90dBFS noise. Amp has insignificant noise but 29dB gain. Speakers give 104dB @ 0dBW. What's the SPL of amplified DAC noise at 1M?

I'm not claiming this scenario is common. Nor ideal. Nor impossible to resolve without replacing the DAC. But I'm pretty sure it is possible for someone to assemble such a system. And that person probably would have been happier with a DAC that has an H2-limited, 90dB SINAD but -120dBFS noise.

You won't hear that DAC's noise while your speakers are shouting 104dB at your ears - it will be masked by the music and burried in the room noise, as well as speaker's THD.

 

[AudioSceptic]

Weeeeellllllll Thomas, what a great comment...waffle waffle waffle...…..gibberish gibberish...…..burble burble....and that's why the DS DAC is such a terrific product, be good y'all

A snippet from there

It seems apparent that the unit wasn’t burned in by the original owner or himself.

Yes, really!

Amir, if you still have it, could you leave it running for a few days and then see if any crucial measurements change? This is, after all a common claim made by the reality-challenged.

 

[617]

Question for people slightly older than me - in the 80s and 90s how were CD players marketed? Were any specifications commonly given? Was the jump in fidelity from tape and vinyl so sudden that most consumers thought they all sounded the same? Or were they marketed on the basis of features not contributing to sound quality?

 

[AudioSceptic]

You won't hear that DAC's noise while your speakers are shouting 104dB at your ears - it will be masked by the music and burried in the room noise, as well as speaker's THD.

But would you hear it between tracks or movements?

 

[BDWoody]

Question for people slightly older than me - in the 80s and 90s how were CD players marketed? Were any specifications commonly given? Was the jump in fidelity from tape and vinyl so sudden that most consumers thought they all sounded the same? Or were they marketed on the basis of features not contributing to sound quality?

Most audio consumers didn't start worrying about it until someone told them they were supposed to. Then suddenly the differences are clear and obvious...

The 'High End' always claimed sonic differences in everything...what else would they have to talk about?

 

[graz_lag]

Question for people slightly older than me - in the 80s and 90s how were CD players marketed? Were any specifications commonly given? Was the jump in fidelity from tape and vinyl so sudden that most consumers thought they all sounded the same? Or were they marketed on the basis of features not contributing to sound quality?

A bit of history :

Why 44.1kHz?
The choice of audio format for CD was a mixture of available technology and what was possible at the time. CD needed a format capable of covering the audible frequency spectrum – 20Hz-20kHz – and that meant a sampling rate of at least twice 20kHz would be required.
Fortunately a solution was at hand, in the form of a technology used to store audio, for example for transfer between studios and so on: Sony's U-matic video tape.
Originally made for professional video applications, this could be used with a PCM adaptor to store six audio samples per video line – ie three samples for each stereo channel.
And given the 245 usable lines per field and just under 60 fields per second of NTSC video, and the 294 lines/60 fields of PAL video, this gave a sampling rate of 44.056 samples per second for each stereo channel on NTSC format, or 44.1kHz on PAL. Not surprisingly, given that Japan was an NTSC territory, that standard was the one the Sony engineers were working to.

Why 16-bit?
The system could store 16-bit samples, but needed error correction to do so accurately, or could store 14-bit with no correction, and for a while the Philips engineers proposed 14-bit with a 44kHz sampling rate, while the Sony team pushed for – well actually insisted on – 16-bit with either 44.056kHz or 44.1kHz sampling.
The difference? Well, the greater the number of bits, the more 'steps' can be used to describe each sample, and more steps means greater resolution.
16-bit provides 65,536 voltage values (or steps) for each sample, while 14-bit gives 16,384 – or in other words a quarter as many as 16-bit.
Going into the CD age, Philips already had a 14-bit digital to analogue converter, but the Sony engineers prevailed, and 16-bit/44.1kHz it was.
For their machines, the Philips team made the 14-bit system deliver the same quality by using four times oversampling – running the converter at four times the 44.1kHz sampling rate – and thus improving resolution while reducing noise.

 

[Krunok]

But would you hear it between tracks or movements?

Even if you have your ears 10cm from the speakers (which you won't have) you won't hear the noise between the tracks as your ears sensitivity would be to low after listening at 104dB for a while. And again, thre's the room noise..

 

[PierreV]

Question for people slightly older than me - in the 80s and 90s how were CD players marketed? Were any specifications commonly given? Was the jump in fidelity from tape and vinyl so sudden that most consumers thought they all sounded the same? Or were they marketed on the basis of features not contributing to sound quality?

There was a lot of marketing against Philips 14 bits with a bunch of now gone niche players claiming 16 real bits. And the usual stuff...

To be honest, for most people, the CD arrival was a stunning improvement. It wasn't even progressive like the arrival of digital photography, just sudden, and quite a shock. Also, since Sony and Philips were the drivers and volume ramped up quickly, prices fell drastically in a year or so. I'd say that, in a way, this was the first time consumers saw a huge improvement compared to what they had and an amazing price drop in a bit more than a year.

I feel that this is also the time high-end audiophile boutique as we know it was born, partly in reaction...

 

[AudioSceptic]

Picosope is not a problem - designing a well performing DAC is about the skill of an engineer, not about a top class measurement instrument.

You still need to test the result, no matter how good you think the design is, and if you are chasing SOTA, you need SOTA measuring gear, or at least arrange to have it tested by someone with same.

 

[Rja4000]

if you use a low noise interface like the Autoranger, you can hit that with ease.

I purchased one. Still have to assemble it though.

 

[Krunok]

You still need to test the result, no matter how good you think the design is, and if you are chasing SOTA, you need SOTA measuring gear, or at least arrange to have it tested by someone with same.

As @scott wurcer explained, Picosope can do many things if used properly by a hands of a skilfull engineer.

 

[scott wurcer]

As @scott wurcer explained, Picosope can do many things if used properly by a hands of a skilfull engineer.

In fact when Bruce Hofer visited ADI he asked to see me and I showed him how I verified op-amp THD without an AP and he said yes that's about what we do to verify the AP.

 

[SIY]

I purchased one. Still have to assemble it though.

It challenged the APx555 for measurement.

 

[Rja4000]

It challenged the APx555 for measurement.

You're speaking about Linear audio autoranger, right?

 

[Juhazi]

But would you hear it between tracks or movements?

No, if the fridge is cooling in the kitchen, or the desktop computer's fan is running.
https://www.audiosciencereview.com/...ting-thd-in-the-perspective.9085/#post-232214