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

[Middy]

A great read, thank you... another good article for 2021 AStyle

Never imagined i'd ever have a Dave and more than content to have a Qutest but i finally get to see a Pimp my ride version of 'Dave'.

I am glad it worked so well and giving you pleasure Ray.

Every bit of nice is need in these times..

Really looking forward to part 2.0

As so many questions with a TOTL upgrade now its  in the MOLA MOLA and Bartok territory.

Already you can see the magnifying of every detail people want to see. Just in the above comments.

 Objective subjective... a literal power struggle of PSUs... 

I cant wait. 

Thank you ever so much for taking the time @ray-dude to document and post this artlcle.

 

Happy 2021 to you and all.

 

A non upgraded..

Dave😁

 

Another tick in the box for well regulated power...

 

 

 

[Middy]

A great read, thank you... another good article for 2021 AStyle

Never imagined i'd ever have a Dave and more than content to have a Qutest but i finally get to see a Pimp my ride version of 'Dave'.

I am glad it worked so well and giving you pleasure Ray.

Every bit of nice is need in these times..

Really looking forward to part 2.0

As so many questions with a TOTL upgrade now its a in MOLA MOLA and Bartok territory.

Already you can see the magnifying of every detail people want to see. Objective subjective... a literal power struggle of PSUs...

I cant wait. 

Thank you ever so much for taking the time @ray-dude to document and post this artlcle.

 

Happy 2021 to you and all.

 

A non upgraded..

Dave😁

 

 

 

 

 

[fas42]

4 hours ago, ray-dude said:

 

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)

 

The behaviour with audio follows the lines of, the closer one is to the best that the components can deliver, the more fussing about every last detail is worthwhile ... IME. That is, many subtleties of how the setup performs in various circumstances is masked, unless a certain of playback quality is reached - if the SQ is already at a Wow!! level, then the real benefits of being adventurous with further tweaking are so obvious ...

[ray-dude]

4 hours ago, Middy said:

Never imagined i'd ever have a Dave and more than content to have a Qutest but i finally get to see a Pimp my ride version of 'Dave'.

 

 

I don't have a Qutest, but I'm 99.9999% certain that the Qutest would be significantly elevated with better power.  Even with my Hugo TT2, better energizer power to the super caps has a surprisingly significant upside.  For something like the Qutest (or bypassing the battery on a Hugo2) I think it is definitely worth exploring if power makes an impact for you.

 

Re the objective/subjective topic that @Archimagoraised, unlike a lot in audio, quality and attributes of power sources are VERY measurable.  In the case of these experiments, I suspect output impedance and transient current capacity are more impactful than any noise on the output, but the experiment with and without the CX noise filter on the output regulator of the DC4 (and what I highlight in part 2 when it gets posted), noise does have a material impact on sound stage and imaging.  I'd love to quantitatively characterize these power sources under normal operating conditions, then use subjective impressions to correlate to objective power supply measurements to see what attributes and performance measures move different SQ needles.

 

 

[asdf1000]

17 hours 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

 

The way I read this , it reads like a switch from SMPS to LPS will result in reduction of leakage current...

 

But if you ask Mr Leakage @JohnSwenson - this is not a guarantee . 

 

There are SMPS's with more leakage than LPS and there are LPS with more leakage current than SMPS .

 

Can't generalise this stuff - can only measure the particular power supply in question.

 

Important note: I would never criticise or question anyone's subjective impressions here... that's not my style. I'm only talking in the objective domain

[MarkusBarkus]

12 hours ago, ray-dude said:

I don't have a Qutest, but I'm 99.9999% certain that the Qutest would be significantly elevated with better power.

Briefly OT: I had a Qutest to evaluate "Chord Sound" before purchasing DAVE. Qutest sounded better with Farad3. Smooth and mellow. Musical. Very nice. 

[Middy]

13 hours ago, ray-dude said:

17 hours ago, Middy said:

Never imagined i'd ever have a Dave and more than content to have a Qutest but i finally get to see a Pimp my ride version of 'Dave'.

 

 

I don't have a Qutest, but I'm 99.9999% certain that the Qutest would be significantly elevated with better power.

I have tried and been lucky with so many great sources Like John S et al and the members here.

My Qutest is on a UPS sinewave 230v out into a balanced isolation transformer. Into an older LPS1 7V into a dual reg Ldovr 5v and IFI DC IPURIFIER..

The delta wasnt as much as we always hope but that extra refinement does stand out.

Blood from a stone at the bottom of the Chord ladder..

Cost conscious small spends.

Why its so nice reading about someones end game efforts turning the great into something above and beyond.  I mentioned this superb article on the Chord owners club on FB. 

A Nick Bacon said he had the  mod done and was one of the best things he has done in his system.

 

Thanks again Ray keep up the good work

 

Dave

 

 

 

[Middy]

Nick Bacons post FB Chord users.

 

https://www.facebook.com/groups/236162336799519/permalink/952557981826614/?sfnsn=scwspmo

 

 

[ray-dude]

2 hours ago, Middy said:

I have tried and been lucky with so many great sources Like John S et al and the members here.

My Qutest is on a UPS sinewave 230v out into a balanced isolation transformer. Into an older LPS1 7V into a dual reg Ldovr 5v and IFI DC IPURIFIER..

The delta wasnt as much as we always hope but that extra refinement does stand out.

Blood from a stone at the bottom of the Chord ladder..

Cost conscious small spends.

Why its so nice reading about someones end game efforts turning the great into something above and beyond.  I mentioned this superb article on the Chord owners club on FB. 

A Nick Bacon said he had the  mod done and was one of the best things he has done in his system.

 

Thanks again Ray keep up the good work

 

Dave

 

 

 

 

The Qutest (esp. when fed with good power and upsampled content from things like HQPlayer) is some of the best bang for the buck in audio!  Very glad that @Fourlegshas been promoting this gem!

[bbosler]

2 hours ago, Middy said:

Nick Bacons post FB Chord users.

 

I don't have a FB account but it was interesting to see the person advocating for battery power as the better solution than linear supplies. I have no comment on which sounds better, but the idea that batteries are perfect reservoirs of energy with no noise is incorrect. They do produce noise, have limited current reserves, an output impedance that is frequency dependent, and their characteristics change as they age.  The ability of a lead acid battery to supply hundreds of amps to the starter in your car does not necessarily translate to the needs of an audio circuit. They are a viable solution in many cases, they just aren't the perfect supply that some envision.

[bobflood]

Power supplies no doubt matter much more than we realize. Both Holo Audio and Dennefrips have gone to great lengths to use linear power supplies and in both of their flagship models they are heroic in nature. What would really annoy me would be to pay the Dave price tag and then have to almost double it to upgrade the power supply. The flagship Holo is about one half the Dave price and comes with a separate linear power supply. My Holo Spring 2 has an internal linear power supply at about one third the Dave cost. I am not saying one is better than another just pointing out the obvious. 

 

BTW these articles should bear the sub-title "An Audiophile Odyssey". :)

[ray-dude]

It most definitely is a Quest Bob, with these write ups being more of a travelogue ;)  

 

I do think the state of the art has evolved a LOT since the DAVE was introduced back in 2015(!!). If/when a mythical DAVE2 gets released, things may be quite different.

 

I am delighted to see newer DACs taking power more seriously, supporting 32fs inputs, etc.  All these make me daydream even more about what a DAVE2 could actually do.

[TheAttorney]

An excellent review @ray-dude.

 

What was the length of cable that came with the DC4?

I ask because the Mundorf silver/gold is very expensive per foot. And the shorter the length the better the SQ.

So short is good - if fit can fit in with the individual rack layout.

 

When you post part 2, it would be good to compare the relative merits of power conditioner vs power supply.

In particular, does TT7 + stock DAVE p/s sound better than DC3 or 4 alone?

And does TT7 + DC3 sound better than DC4 alone?

 

As I've mentioned elsewhere, if I go down this route, I'd go for a bespoke DC3+ because of my downsizing objectives.

I.e. as many DC4 components that will fit inside the much smaller DC3 enclosure. In particular, the DC4 regulators  and TOTL caps. Judging from the photos, we should be able to squeeze in the same quality transformer, but maybe at reduced power rating and certainly not the extra damping and screening enclosure. And will probably have to reduce the amount of reservoir caps. The end result should be somewhere between the current big gulf between DC3 and 4 in both price and performance.

 

I have an elderly Audience TSSOX power conditioner, which seems to have very similar design objectives to the TT7:

A low impedance, passive filter, based on top Teflon caps, non-MOV spike protection and power-factor correction.

The fact that the already-expensive Audience costs so much less than the TT7 (and probably with much lower performance), shows that attention to details matters a lot here as in everywhere else.

 

 

[ray-dude]

The DC4 umbilical I have is ~3' long.  @Nenon and I have been chatting about giving a Mundorf silver/gold cable a try, but with holiday schedules, we haven't gotten around to that yet.  Given what Nenon and others have heard in other applications, I am enthusiastic about what an upgraded cable will bring to the party.

 

If you're willing to place your DAVE on top of the DC4, the umbilical length can be quite short (<1').  For vibration control reasons, I'd prefer to keep each on its own stack, so the minimum length for me would be at least 18" (assuming side by side like I have in the photos). If you have a robust rack, then options clearly open up for a vertical layout.

 

There are certainly many paths to power nirvana, and it continues to be interesting to compare the piece parts of DC3 and DC4. The 5V line is primarily digital, and the ±15V lines are primarily for the analog stage. Does it make sense to optimize these for different dynamic loads and noise sensitivities? Different wiring to reflect these loads/sensitivies? Different classes of filters? Being able to separate out the 5V line from the ±15V line is a boon for experimentation, and I continue to learn a heck of a lot about how different power aspects impact different aspects of sound (hence my longing to bring some object measurements to the party...with full measurements the optimization/tuning process would be a heck of a lot less empirical).

 

Certainly compared to my DC3, the DC4 has advanced the state of the art considerably (to say the least). I suspect the next frontier is individual tuning of the digital and analog lines for a bit extra synergy with the particulars of the DAC, but we're definitely at the point of diminishing returns.  Of course, when we do fully optimize power for the DAVE, the audio gods will conspire to have that be the same week Rob announces his next TOTL DAC, so the cycle can begin all over again....

 

 

[bbosler]

11 hours ago, ray-dude said:

The 5V line is primarily digital, and the ±15V lines are primarily for the analog stage.

 

so another opportunity to to pursue the ultimate. Pretty sure the display runs off of the higher voltage and assuming it is an off the shelf display must be running its own microprocessor and clock. Shouldn't be terribly difficult to isolate the DC feed to the display  since it has a ribbon cable running to it and power it with a supply separate from the analog circuits.

 

just in case you were running out of things to obsess about.. you are welcome 😆

 

 

[ray-dude]

Believe it or not, DAVE has a display mode where the display turns on when you change something, then turns off.  Rob did call out the SQ benefits of having the display off while playing music ;)

 

 

[bbosler]

6 minutes ago, ray-dude said:

has a display mode where the display turns on when you change something, then turns off.

 

DOAH !! I knew that, I used to own one. But you wonder how much it is actually off? Maybe just the lights and the rest is running in the background polluting the 15V line? 

 

I couldn't justify the incremental if at all increase in sound quality from DAVE over my Antelope Eclipse so sold it. Use HQPlayer for the upsampling. No doubt you hear something I didn't so I'm happy for you,  and even happier for me as I have that much more to invest in my analog front end. 

 

Reading your Extreme series I discovered driving my speakers from the headphone outputs of the Antelope and running it off of linear supplies (Keces in this case) so I thank you for that insight. 

[atmfrank]

https://www.bursonaudio.com/about-us/max-current-power-supply/

 

[Datka]

Hi Wonder if following would work

 

For Chord DAVE purchase 2X  Farad Super 3 power supplies :

 

1X Farad Super 3 for 5Volt digital related loads and 

1X Farad Super 3 for 15 Volt Analog related loads ?

 

its a 4 pin connector , so local Audio technician should have no problem connecting 4 wires?

 

So is my thought process off charts here or any issues with what i'm trying to explain here ?

 

Pricing for both Farad3 should be in 1000K area and Farad3 seems to be  very highly reviewed online....

 

Thank you for your input...  

 

[ray-dude]

Remember that you have -15V as well, so you would need three supplies.  These supplies have enough current for the job so they would work.  How they would compare to other options is TBD (I've tied multiple supplies on the 5V rail, but I did not have a Farad to test...they all have a different characteristic sound)

[bbosler]

I used Keces supplies. You can use a dual 15V supply as long as they are floating. 

[skatbelt]

6 hours ago, bbosler said:

I used Keces supplies. You can use a dual 15V supply as long as they are floating. 

 

So one JS-2 (both rails modded to deliver 15V) plus one LPS 1.2 would also work with this scheme.

[bbosler]

3 hours ago, skatbelt said:

 

So one JS-2 (both rails modded to deliver 15V) plus one LPS 1.2 would also work with this scheme.

 

no, the rails are on the JS-2 are not floating with respect to each other. It cannot be used to to provide plus/minus 15V. You would need 2 of them.

 

you could use an LPS 1.2 for the 5V but you would be working closer to its 1.1A max rating than I would be comfortable with

[ray-dude]

This is true.  DAVE 5V draws 0.7-1A (or so).  LPS 1.2 really shines at lower current draw.  That being said, LPS 1.2 5V >> DAVE SMPS 5V (at least in my living room).  A higher current capable device (ldovr, JS2, etc) could be higher performing still.  For example, I thought the ldovr 3A 5V supply to perform better than the LPS 1.2

[bbosler]

I just rearranged things in my system so I have 2 Keces power supplies for sale along with a harness to hook them up to a DAVE. I'll post in the for sale section and on Audio Mart. No longer have a DAVE or have any use for these supplies as I bought a Denafrips Terminator Plus..