Article: Reality Quest: Power and Digital Audio with the Sean Jacobs DC4 and Sound Application PGI TT-7 (Part 1 of 2)

[ray-dude]

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[The Computer Audiophile]

So neat to read about all this Ray and follow the journey. Thanks so much for Part 1, I can't wait for everyone to see Part 2 :~)

[austinpop]

Excellent as always, Ray! A riveting read.

 

I’ve long been an advocate of modularity in DACs, especially when it comes to power supplies. This is an emphatic case in point.

[ray-dude]

100% agreed Rajiv.  There are very practical constraints (BOM, room in case, etc) with any piece of equipment, which I appreciate and respect.  That being said, modularity (especially for modular components) enables customers to calibrate their investment to their own objectives/constraints. 

[ASRMichael]

I love reading your reviews! It’s like going on an amazing scenic train journey! 

[kennyb123]

Superb job on this @ray-dude!  I especially liked the walkthrough of the two power supplies.  The DC4 sure is a beauty.    

[ALLDIGITAL]

Ray, thanks for sharing your journey with everyone. This was so well written and insightful, that it was like reading a "who done it" thriller that is leaving me at the edge of my seat waiting for the next chapter. Well done!  All Digital

[ted_b]

Great storytelling Ray, and great overall writing.  This part one was a quite a teaser, too.  BTW, what does Rob say (I love Rob too) when you explain to him the differences you hear with Sean's power supplies?  Also, what/where will the Hynes fit in this architecture?  Replace the DC4?

[MarkusBarkus]

Although I had studied the pics before the conversion, it was still sobering to see the little CNC-ed chamber and aluminum billet walls created to isolate the stock PS. 
 

I suspect just pulling the stock SMPS out of its coffin and putting it in an external box would improve sound, for those without a DC4 budget. I think that would be do-able.

 

And great call-out on the connector. I used blue tape to index the orientation in case I lost my mind and my nerve reconnecting it!

 

Great article, Ray. Mark

[ray-dude]

6 hours ago, ted_b said:

Great storytelling Ray, and great overall writing.  This part one was a quite a teaser, too.  BTW, what does Rob say (I love Rob too) when you explain to him the differences you hear with Sean's power supplies?  Also, what/where will the Hynes fit in this architecture?  Replace the DC4?

 

Ted, Rob is pretty clear that he thinks other power supplies are not only not helpful, but detrimental.  That being said, him voicing that opinion was (generally) a couple years ago, and there has been huge progress in upsampling (mScaler), digital servers, power, etc. since then.  Alas, with Covid restrictions, it is very difficult to be gathering in the same space to hear the same things.  Hopefully soon (and again, there is literally no one in digital audio I respect more than Rob Watts).

 

I am continuing work to experiment with different power sources, build on the findings with the DC4.  A DR SR7 for the three rails may be a winner over the DC4, it may not (but it would be a replacement).  With Paul building custom SR7's again, hopefully there are some in the wild soon to test this (alas, my build is well down the queue)

 

[ray-dude]

4 hours ago, MarkusBarkus said:

Although I had studied the pics before the conversion, it was still sobering to see the little CNC-ed chamber and aluminum billet walls created to isolate the stock PS. 
 

I suspect just pulling the stock SMPS out of its coffin and putting it in an external box would improve sound, for those without a DC4 budget. I think that would be do-able.

 

And great call-out on the connector. I used blue tape to index the orientation in case I lost my mind and my nerve reconnecting it!

 

Great article, Ray. Mark

 

Mark, FWIW, the DAVE SMPS vs DC3 test I wrote up in listening tests had the stock SMPS outside the DAVE case in a cardboard box ;)

[Archimago]

Interesting read. Glad you liked the results...

 

Just to state the obvious. I think it would be really nice to have a quick look at the noise level coming out of the DAVE with its stock SMPS vs. the others.

 

The reason I bring this up is that in the past I have found at least one example where the power supply can clearly affect noise level and it was in fact a linear power supply that was problematic for the DAC. Sometimes the noise is ultrasonic so you won't necessarily hear the issue but nonetheless is being fed to the amp and speakers. Furthermore, you might find situations where as the power supply warms up, the noise will fluctuate over time.

 

Considering the price of the DAVE, effort to open it up, warranty exceptions, etc... it would be nice to go that extra mile and ensure there are no issues with measurements.

[ray-dude]

Measurements would be very helpful Archimago.  I'm seeing different trends with 5V line vs ±15V lines, but I would love to map that to measurements to see what the correlations are.  Right now, I'm having to indirectly ascertain stuff, but I do feel like a naturalist in an EE world (as an EE, not an easy thing to say).  Subjectively, the impact is very clear, but objectively, why?  I'd love to know to more directly optimize the subjective outcomes.

[The Computer Audiophile]

11 minutes ago, Archimago said:

Interesting read. Glad you liked the results...

 

Just to state the obvious. I think it would be really nice to have a quick look at the noise level coming out of the DAVE with its stock SMPS vs. the others.

 

The reason I bring this up is that in the past I have found at least one example where the power supply can clearly affect noise level and it was in fact a linear power supply that was problematic for the DAC. Sometimes the noise is ultrasonic so you won't necessarily hear the issue but nonetheless is being fed to the amp and speakers. Furthermore, you might find situations where as the power supply warms up, the noise will fluctuate over time.

 

Considering the price of the DAVE, effort to open it up, warranty exceptions, etc... it would be nice to go that extra mile and ensure there are no issues with measurements.

I wish all people who want measurements would say it this way. Bravo @Archimago . 

[ray-dude]

1 minute ago, The Computer Audiophile said:

I wish all people who want measurements would say it this way. Bravo @Archimago . 

 

I wish all of us that can't (currently) do measurements lived close enough to @Archimago so we could take our toys over and cross map measurements to subjective experience! (over an appropriate beverage (or three) of course)

 

 

[The Computer Audiophile]

1 hour ago, ray-dude said:

 

I wish all of us that can't (currently) do measurements lived close enough to @Archimago so we could take our toys over and cross map measurements to subjective experience! (over an appropriate beverage (or three) of course)

 

 

Totally! 
 

It would be enjoyable and enlightening. 

[Archimago]

4 hours ago, ray-dude said:

 

I wish all of us that can't (currently) do measurements lived close enough to @Archimago so we could take our toys over and cross map measurements to subjective experience! (over an appropriate beverage (or three) of course)

 

 

 

Absolutely. Wish you were closer! You've got some great gear there @ray-dude!

 

The DAVE's output would be an interesting one to examine because of the very clean, strong "ideal" filter it implements. Changes to things like dynamic range, noise floor and variations in harmonic distortion could show quite clearly with a DAC like that. Would be a nice documentation of the effect that the power supply has.

[asdf1000]

6 hours ago, ray-dude said:

Ted, Rob is pretty clear that he thinks other power supplies are not only not helpful, but detrimental.

 

Actually Rob has not said this - he says other power supplies MAY be detrimental.

 

There is no way Rob has measured everything single power supply on earth, so there's no way he could make any claim about all other power supplies.

 

What he's said is that well designed SMPS's like he chose to use in DAVE  performed better (objectively) than linear PSU's he measured. He's said many linear PSU's have terrible RF filtering. SMPS's can have very good RF filtering.

 

So there are great SMPS's, there are great linear PSU's. And there are bad SMPS's (very high leakage current output for example) and there are badly performing linear PSU's (no RF filtering for example).

There's no way to generalise and Rob is careful about this. He only talks about what he's measured himself.

 

The only way to know is to measure the particular PSU in question.

 

 

[ecwl]

I have often wondered how much of the sonic improvement is due to a switch from SMPS to LPS thus reducing high impedance leakage current coming from the PC and how much of the sonic improvement is due to actual improvements to the power supply (noise in the DC current, impedance, etc.) Theoretically, one can test it out by feeding DAVE via Toslink using stock SMPS vs DC4 to compare.

As someone who switched back to Toslink to avoid high impedance leakage current for DAVE, I have to admit it's a bit inconvenient.

So at the end of the day, I think the system we want to have is the system we want to have. So if the DC4 upgrade is superior to the stock SMPS in @ray-dude's system sounds better, that's awesome. And it is great to be able to read about the experience and find out more about DC4. Very neat.

[The Computer Audiophile]

1 minute ago, ecwl said:

I have often wondered how much of the sonic improvement is due to a switch from SMPS to LPS thus reducing high impedance leakage current coming from the PC and how much of the sonic improvement is due to actual improvements to the power supply (noise in the DC current, impedance, etc.) Theoretically, one can test it out by feeding DAVE via Toslink using stock SMPS vs DC4 to compare.

As someone who switched back to Toslink to avoid high impedance leakage current for DAVE, I have to admit it's a bit inconvenient.

So at the end of the day, I think the system we want to have is the system we want to have. So if the DC4 upgrade is superior to the stock SMPS in @ray-dude's system sounds better, that's awesome. And it is great to be able to read about the experience and find out more about DC4. Very neat.

Well said.

[jeffhenning]

John Siau, who's the chief designer & CTO at Benchmark Media, said it best when, in an interview, stated that if you need a power conditioner for your system to sound its best, your equipment has really terrible power supplies in them.

 

Here would be my thought: rather than waste money on a 3rd party power supply, buy a better DAC.

 

From what I can tell, all of these products are garbage. 

[The Computer Audiophile]

1 minute ago, jeffhenning said:

John Siau, who's the chief designer & CTO at Benchmark Media, said it best when, in an interview, stated that if you need a power conditioner for your system to sound its best, your equipment has really terrible power supplies in them.

 

Here would be my thought: rather than waste money on a 3rd party power supply, buy a better DAC.

 

From what I can tell, all of these products are garbage. 

Wow. You’ve chosen to believe John as opposed to others. Can you say why you appeal to this authority?

[PeterG]

Great piece!  Let's hope this evolves into a plug and play solution for those faint of heart

[ray-dude]

52 minutes ago, PeterG said:

Great piece!  Let's hope this evolves into a plug and play solution for those faint of heart

 

Way back in the day, I got one the very first DC3's for DAVE. It was a very scary experience to crack the case and figure out stuff (and still is). I do know several people who've sent in their DAVE's to have the umbilical installed and their DAC tested with their supply, so there are options to make things more plug and play.

 

That being said, the more DAC manufacturers move to separate modular power schemes, the easier it will be to have true plug and play. Separating out the power supply from the core DAC is inconvenient from a manufacturing and sales experience, but for folks that are buying/selling modular components (particularly at the high end) I think it very necessary and potentially very impactful on SQ.

 

Modular isn't ideal for everyone though. There will always be a market for all in one type systems (streamer+DAC etc) where the convenience of one box will win out.

[ray-dude]

1 hour ago, jeffhenning said:

John Siau, who's the chief designer & CTO at Benchmark Media, said it best when, in an interview, stated that if you need a power conditioner for your system to sound its best, your equipment has really terrible power supplies in them.

 

This may be a better conversation after part 2 is posted (re the Sound Application PGI TT-7 power line conditioners)  It had a pretty stunning impact for me across all my components (and my TV).  Diving into the details of the TT-7, it would be a very steep ask for component level power supplies to do similar filtering (although of course it is in the ear of the beholder whether than level of filtering has value)