Half Classic Power Supply/ Half Precision Power Supply

[nicosci]

Hi!

I'm planning to convert my Precision Power Supply to a Classic 4x 22uF supply (dropping stages).

Now I am starting to think "what if" I only convert the b4 and b5 nodes only? (reverb/mixing stages V2 & V4 and then V1) leaving the Plate & PI supply stock as 2 pairs of 47uf wired in series. What could the effects be?

Thanks to all your wisdom and kindness! Very much appreciated as always!
Cheers!
Nick

[ijedouglas]

Hi,

I don't think there is much difference between the 2 topologies. Precision has 4 pairs of 47uf in parallel to give you an effective 23.5uf whereas the classic has 4 individual 22ufs. I don't think there is any "current on tap" increase with precision. I honestly haven't A/Bd the 2 in the same amp but I think the only difference would maybe be a "feel" difference due to different caps/brands. Unless you are trying to replicate an amp, precision may be a better choice due to future parts availability.

[pompeiisneaks]

Hi,

I don't think there is much difference between the 2 topologies. Precision has 4 pairs of 47uf in parallel to give you an effective 23.5uf whereas the classic has 4 individual 22ufs. I don't think there is any "current on tap" increase with precision. I honestly haven't A/Bd the 2 in the same amp but I think the only difference would maybe be a "feel" difference due to different caps/brands. Unless you are trying to replicate an amp, precision may be a better choice due to future parts availability.

This was also my understanding, the point of the precision power supply was that readily available radial style caps were extremely high quality, smaller and much less expensive than the older style axials.

smaller, better, more of the same thing.

~Phil

[nicosci]

I respect that view, and I agree on why you'd choose PPS. Except there's that camp that hears that softer character that a low filtration classic ps gives.

It's been mentioned numerous times as well that a Series (parallel adds capacitance not half) config does provide more instant power. Now here's where " im not an expert" comes in i guess but when i research something I like to take that info into consideration. Plus I actually had my V1 node low on current/ +-a few volts and I actually achieved the sound I want. Just not the correct way lol.

So still I wonder if its at least safe to do a combination of the topologies.

[ijedouglas]

(parallel adds capacitance not half)

Thought series and wrote parallel I'm not sure how it could provide more power.. I'm always open to learn if you have a link handy.

I would go with what you feel is a better option. I don't think there is any issue with combining them

[nicosci]

(parallel adds capacitance not half)

Thought series and wrote parallel I'm not sure how it could provide more power.. I'm always open to learn if you have a link handy.

I would go with what you feel is a better option. I don't think there is any issue with combining them

Sure I'll be happy to link em up as I find them in my bookmarks and what not. There's a thread as well I think.

Anyway I really appreciate your ideas thank you. Good to know. I like to discuss things before I do anything Cheers

[talbany]

Here is one that is sort of a hybrid. Plate caps are series/Parallel (Double the caps)For a total of 100uF. both Axial (screen V1-V2) and radial (PI). This is a Music Man 700v ODS style P.S/ Precision (High surge)

192_82k_annotated.jpg

Tony

[nicosci]

Wow very interesting intense stuff , thanks Tony. Good to see these kinds of power supplies. Oh mahn 700 volts

Also to add, the reason I wanna keep the series/ parallel config on the rest of the stages (Pi, Plate) is that I wanna keep the headroom and dynamics but still get that softer clean up front in preamp, plus I don't want to deal with a lot of re solders unecessarily lol, less invasive, the better.

[talbany]

Wow very interesting intense stuff , thanks Tony. Good to see these kinds of power supplies. Oh mahn 700 volts

Also to add, the reason I wanna keep the series/ parallel config on the rest of the stages (Pi, Plate) is that I wanna keep the headroom and dynamics but still get that softer clean up front in preamp, plus I don't want to deal with a lot of re solders unecessarily lol, less invasive, the better.

For me personally I prefer the older larger "Classic" Axial style P.S. and moved away from using the new stacked Radials. Here is an interesting paper on Filter caps performance in a 5F6 Bassman

CONCLUSIONS
The WILDCAT team concludes that AC ripple present in the power
stage represents much more than just noise. Its modulation of the
output appears to have a significant effect on the Bassman's sonic
character.

Bassman Experiment Copy.pdf

Tony

[nicosci]

Here's an example of why I said two series caps "gives more instant power" per googling:
"two small capacitors with a total equivalent capacitance to one large capacitor have a faster response time than a single capacitor."

[ijedouglas]

I have no doubt that there will be a different feel to the amp and I am certainly no electronics expert but I think the cap construction (brand/model) will have more influence on the sound/feel than the topology. I have amps with both topologies but I have not swapped them between these amps to test differences in feel/tone. I have done a lot of testing with caps/brands/models and there is a huge difference in tone and feel. At the end of the day you probably won't know whether you like it until you try it

[nicosci]

That's good to know! In fact I have F&T caps on the way, so I'm excited that they're better perhaps than my oem ceriatone ones, also they're 22uF so not far from the capacitance I have right now which is 47uF divided by 2.

Funny thing, I should've included the actual link in my post above ^ https://ampgarage.com/forum/viewtopic.php?f=4&t=20344
So sorry for the confusion.