Been way too long and missing many wonderful things happen in the forum
to busy sorry to say .
Most of you know that i currently construct P3A and allready produced 5231 different PCB implementing mods and different styles .
2026 will be 20 years ( man time flyies ) that i am doing that .....
So since i am having a brake from too much work ( had a really rough last year concidering volume of work ) i am willing to construct once more but this time with regulated rails or capacitance multiplier ....
Quad did in the past , Naim did in the past and soon (since classAB is a dead end ) we will see one of the big names of hi end comming with one machine ( range 50K ) that will be a typical hi end class AB ( includes extreme enclosure style and loads of transistors ) but this time with IGBT regulated rails .
Question is that if anyone thinks that is going to be any audible benefit from that ?
Question is that if this benefit will apply from low listening level till clip ?
Question is regulated rails or capacitance multiplier and why ?
My only previous expirience was with QUAD wich the all thing was single rail, capacitor coupled, sorry excuse of amplifier circuit .
BUT !!, people that used them actually as pro amps in small bars said that they sound very good , amplifier is indestructable and impossible to destroy a speaker with it ... ( probably this has not much to do with regulated rails , but mostly because is capacitor coupled )
Place your comments please
i will be more than happy to listen
thank you
to busy sorry to say .
Most of you know that i currently construct P3A and allready produced 5231 different PCB implementing mods and different styles .
2026 will be 20 years ( man time flyies ) that i am doing that .....
So since i am having a brake from too much work ( had a really rough last year concidering volume of work ) i am willing to construct once more but this time with regulated rails or capacitance multiplier ....
Quad did in the past , Naim did in the past and soon (since classAB is a dead end ) we will see one of the big names of hi end comming with one machine ( range 50K ) that will be a typical hi end class AB ( includes extreme enclosure style and loads of transistors ) but this time with IGBT regulated rails .
Question is that if anyone thinks that is going to be any audible benefit from that ?
Question is that if this benefit will apply from low listening level till clip ?
Question is regulated rails or capacitance multiplier and why ?
My only previous expirience was with QUAD wich the all thing was single rail, capacitor coupled, sorry excuse of amplifier circuit .
BUT !!, people that used them actually as pro amps in small bars said that they sound very good , amplifier is indestructable and impossible to destroy a speaker with it ... ( probably this has not much to do with regulated rails , but mostly because is capacitor coupled )
Place your comments please
i will be more than happy to listen
thank you
I'll jump in ...
There are some circuit configurations that benefit (much) more from regulated/cap-multiplied rails. I suppose p3a might not benefit that much - but I am no expert!
P3a will definitely like a clean dc source, low impedance off course, i just bought a qa403 , i will post som measurements today, 4 different measurements at different bias levels. Im thinking 50ma 100ma 150ma 200ma, see how it beshaves.. i do have som capacitance multipliere i could hook them up afterwards, and re test, see the differences..
Its a shame nobody is interested in p3a any more, its a very good amp, my speakers are 95db , and the love p3a..
Its a shame nobody is interested in p3a any more, its a very good amp, my speakers are 95db , and the love p3a..
What is P3A ? Rod Elliots P3A ?
Basic 2nd gain stage, which is where the H2 comes from.
" warm" distortion
Multiple outputs is a great idea.
Between the DC offset and Bootstrap it wont be easy to stabilize a CFP
output with multiple devices.
Negative rail will ring,
Driver degen is mandatory
needs a mirror and no boot strap
THD + Noise gets better if the noise part goes away.
Of course the THD part wont get any better.
So not much to work with if the rails are cleaned up.
Basic 2nd gain stage, which is where the H2 comes from.
" warm" distortion
Multiple outputs is a great idea.
Between the DC offset and Bootstrap it wont be easy to stabilize a CFP
output with multiple devices.
Negative rail will ring,
Driver degen is mandatory
needs a mirror and no boot strap
THD + Noise gets better if the noise part goes away.
Of course the THD part wont get any better.
So not much to work with if the rails are cleaned up.
I agree on most part, but i do love the little p3a, it sounds lovely on efficient speakers, all those changes will take away its charme.
It does not produce very good figures , i see lots of harmonic distortion similar to tube amps, but they are ear friendly at modest levels.
My p3a uses
Bc550c on differential pair.
2sa1145 as vas .
Drivers are TTC004B TTA004B.
Outputs are 2SC2922 2SA1216.
100r on q1 q2 emitters.
It does not produce very good figures , i see lots of harmonic distortion similar to tube amps, but they are ear friendly at modest levels.
My p3a uses
Bc550c on differential pair.
2sa1145 as vas .
Drivers are TTC004B TTA004B.
Outputs are 2SC2922 2SA1216.
100r on q1 q2 emitters.
I may try that combination. As it stands my P3A keeps finding its way back into use.
A few months back I bought a Yamaha N600 amp and thought "wow, this is great and it has a remote". I put the P3A in the attic and thought I was done with it. As the weeks went on I found myself listening to music less and less and sometimes even being annoyed that it was on. I got the P3A down and all was right with the world again.
This is one reason I'm not a fan of quick A/B testing.
A few months back I bought a Yamaha N600 amp and thought "wow, this is great and it has a remote". I put the P3A in the attic and thought I was done with it. As the weeks went on I found myself listening to music less and less and sometimes even being annoyed that it was on. I got the P3A down and all was right with the world again.
This is one reason I'm not a fan of quick A/B testing.
I promised some screenshots from qa403, but im having issues with its current draw, if you notice the red box below, just a tad over 4v.
I should receive a better cable soon.
But heres one screenshot.. load is 8 ohm, 2.5v rms.
Thats roughly 0.0033% distortion.
I Dont trust the readings totally until the red box turns green.
Also im new to qu403 so i need to get to know better .
I should receive a better cable soon.
But heres one screenshot.. load is 8 ohm, 2.5v rms.
Thats roughly 0.0033% distortion.
I Dont trust the readings totally until the red box turns green.
Also im new to qu403 so i need to get to know better .
More trouble.. i tested p3a from a siglent lab psu, right before p3a i have two large epcos sicorel 10000uf... It seems my lab psu is not happy with running capacitve loads..
I need to make a old style power supply with transformer and capacitors instead, when i try push p3a the lab psu becomes unstable.
I finish my chores and bash together a stable clean dc source...
I need to make a old style power supply with transformer and capacitors instead, when i try push p3a the lab psu becomes unstable.
I finish my chores and bash together a stable clean dc source...
Noticed your post only now at the moment it had exactly 666 views. You should think of more descriptive thread title next time. 😆
My opinion is that you can’t have a very good power amplifier without the very good power supply. That doesn’t mean regulated supply and nothing else, but good regulated supplies are impossible to beat. There are some excellent amplifiers that wouldn’t benefit from the regulated supplies, except in some extreme measurements. IMO, P3A is not in that category.
Here is a real experience from one P3A owner, where he got better sound by using regulated power supplies:
https://www.diyaudio.com/community/...ower-supply-r21-ps-module.376003/post-7660721
Again, it depends on specific design but on most amplifiers with low PSRR, there will be very noticeable improvement in sound. On low listening levels, you’ll get dead silent background which will enable to hear low level details. On very high levels, amplifier will have less distortion (up to the clipping) and sound is usually perceived as less compressed or more dynamic.
Capacitance multipliers have no regulation. They are very efficient in removing ripple and are very suitable for low loads. Though, they have a high output impedance and are not so great with high dynamic load as is a power amplifier. You can partially improve performance by adding a large capacitor at the output of capacitance multiplier. Sounds contradictory, isn’t it:
https://www.diyaudio.com/community/...-at-the-capacitance-multiplier-output.389938/
So, regulated power supplies with low noise, high PSRR and excellent transient response are what is required. What power amplifier needs is a supply that keeps it output unchanged (except for uV range changes) under any musical load. Unfortunately, there is a lot of excellent power amplifiers, but very good regulated supplies for power amplifiers are rare as hen’s teeth.
https://www.diyaudio.com/community/...ilter-and-super-regulator.420933/post-7865921
Not really.. i used parts collected over many years.
You should check out the old p3a thread, there are many good suggestions
You should check out the old p3a thread, there are many good suggestions