P20 & P15 Regenerator Performance Tweaks and Digital Stream Enhancements, plus BHK Preamp

Power Components
805

I have been able to hear performance fluctuations due to issues with high incoming distortion though outgoing will read the same low distortion. Also disturbances from the sun or lunar will make music sound sub par. Then listening late at night at 3AM when demand on power grid taper in spring or fall when it is cooler the system will sound amazing when HVAC grid load is down. Full of 3D and floating images. Though the meter on P-20 doesn’t read differently. The human ear can be an amazing tool far more sensitive than one would think.

Most likely there is an explanation of power grid anomaly causing what you heard.

806

Interesting, indeed that was probably the case.
What’s disappointing is that the P20 is supposed to regenerate and be devoid of incoming power inconsistencies!
It was bad enough to make my system unlistenable.

I’ll continue to monitor it…

Not sure if this is related but where the renegeration case weakens is when incoming voltage < output voltage. Not sure how the unit adds voltage. It must be at the expense of THD and/or peak current delivery?

807

Could this be mitigated with ground plane reduction techniques? Do you think it’s ground plane noise?
What I noticed is that the background hiss is higher in frequency - it’s like there is an additional higher frequency hiss, on top of the “normal” background noise.

808

I know the power cord on P20 can make things quieter. Having tried many different ones. The presence of RF antenna ground drain and low impedance silver ground wire of low gauge can easily be heard as lower noise floor.

1 Like
809

Hi Folks,

Are you ready for some exercise, to lift and open your P20 and P15? :blush:

After my recent “upgrades” on my DS Sr. and Matrix SPDIF2 with the AB7050HF (Modding the DirectStream DAC - #4166 by nimitz), I started searching for @Vmax P20 – P15 topic, and I read it all.

I then focused, not only on @Vmax experience, but more specifically on @dchang05 and @2muchgear feedback and experience, since they both worked on their P15, which is what I have powering my system.

I had a big piece of AB7050HF left and two little ones (one of them 10cm x 4cm like the pieces used at the far right of the P15 folks).

I then started playing around. I placed the 10x4 on the right side, after the heat sink and when the P15 display ends. It seems I heard more clear vocals (maybe). I then put the other piece (uneven piece of 11x10cm more or less) at the center of P15 (align with the front and touching the other piece). Meh… something was off. I returned to just the little one. I then move it centered with the screen. More noticeable the clearer vocals and a little more “air”. I then tested a big piece (20x21cm) at the center of P15, at far right (P15 display side), and didn’t like the result.

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At first, I didn’t want to disconnect everything, and remove the P15 out of the rack to put the 3M inside, but then, I cross checked my findings with @dchang05 and @2muchgear results and pieces of AB7050HF placement and… I had to open it to take a close look. Before, I looked for some specific P15 photos I had (and others from other users).

I opened the P15 and voilá! Perhaps isn’t the display, perhaps isn’t the transformed, it must be the PIC/control processor/display processor!!! Again.

P15
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And my results with the 3M on the top of the lid are also supported by the P20 folks’ results (which as the PIC/control processor/display processor board and the center a little to the left), where the P15 has it at the right.

P20
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I went and compared the display/PIC board on my P15 and is exactly the same as the display/PIC board on my DS Sr. (both units from 2020).

As @tedsmith said a few years back “In Sr: The PIC/control processor/display processor on the back of the display board is the worst offender in the box. (80MHz plus all sort of impulses reading flash and ram, etc.)”

I then did on the P15 exactly what I did on my DS Sr. I didn’t put any other piece of 3M inside (not on lid and on any other place).

My P15 display/PIC board before:

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My P15 display/PIC board after:

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My DS Sr. display/PIC board after:

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The display/PIC board should be the same on the DS Sr, P15, P20. But here, someone from PS Audio could confirm.

The end result is more than noticeable!

It touches areas usually affected with power cables and power amps changes/upgrades. More strength, bigger soundstage, more “air”, more 3D, but with great refinement.

Thankfully I ended up removing the P15 from the rack and look inside!

Many thanks Vmax and all the other folks for sharing.

PS: If anyone try this, please share the results.

7 Likes
810

Thanks for the splendid work. I want to make sure I got this right. So, instead of placing the 3M absorbent on the lid, you place small 3M squares on top of the processors on PIC and control boards instead. This gives you better results, am I right?

1 Like
811

I believe he did lid and the PICC board ICs. I will try the ICs for Grins

812

Sounds like you’re ready for my absorber tuning rings on your power cables now with sorbothane under the tuning ring. You better strap in for that! Glad you’re enjoying these tweaks.

1 Like
813

I will wait for your feedbacks on the IC tweak before I start doing some heavy lifting!

2 Likes
814

My P20 is on top shelf.

1 Like
815

Mine is at bottom, but P15 is lighter than P20 and will not break my back (or hurt my golf game)! :smile:

3 Likes
816

Just on the board. No lid. :wink:

817

Still have to check the tuning ring tweak. :grin:

818

Same as mine, and without many clearence for the upper shelf.
It’s not the weight, but those heat sinks… :hocho::hocho::hocho::grimacing:

1 Like
819

Interesting no lid. The lid takes lots of adjustments for right spot. However everyone’s systems differ. The tuning ring is different on power cables dependent on their wire geometry. The DC power cable off LPS is a great place discovered by @Duncan_Taylor a half inch wide ring set back a inch or two from LPS. Duncan has great ears from his audio recording experience and makes great power cables.

1 Like
820

One of these days I may try this new 3M tweak from you. But I think this makes sense since it works on DS, so it should work here too. I need to check if I have enough 3M pieces left to try it.

@vmax will probably beat me to it. :slightly_smiling_face:

1 Like
821

I’ll check that.
Thanks.

822

The pieces sizes are:
14mm x 20mm
14mm x 14mm
11mm x 11mm
So very little 3M stuff.

Go for it! :wink:

1 Like
823

With the P15 open and on the “surgery” table, I had to make a decision, since I didn’t want another “exercise session” (specifically one of my fingers, :face_with_symbols_over_mouth: heat sinks!), and I was convinced it was the display/pic board (thinking that the lid placement was “only” taking care of the reflections and not the actual culprit).
So I just did the display/pic board.
After all settled, I did put the 10 x 4cm piece again on top lid centered with the display, and didn’t heard any distinguable change.

824

I do have enough 3M left so I will give it a try!

1 Like