Genuine ESP PCBs are fine for this amp. Even biased to 1.5A (for ESP Project 3B Class-A version) they're fine. I have built two stereo P3 amps and both have been running without a glitch for 5 years+ already. Only issue is that if the PCBs are dissected for installation on opposite sides of a chassis, then a hack should be done to correct some bypass caps and if biased high (like for P3B) then a 10R ground lift ought to be installed at the signal input of each half PCB to address circulating chassis current issues (that I encountered anyway).
If I were building another stereo amp there would be no question - a single (non-dissected) stereo P3A PCB from Rod Elliott in standard A/B bias on a single heatsink.
BTW, Q6 and Q9 ought to be glued to each other. Original PCBs enable that!
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
If I were building another stereo amp there would be no question - a single (non-dissected) stereo P3A PCB from Rod Elliott in standard A/B bias on a single heatsink.
BTW, Q6 and Q9 ought to be glued to each other. Original PCBs enable that!
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Now it's corrected.....thanks you .
Regards,Alex
Hi Alex mm.
Very nice. Some thing to learn from you always. Can I fit a metal plate to the 3 to-126 transistors in the center as a heat sink? Have you had a chance to test it?. .
I know this....3 years ago ,reverse engineering.
http://www.diyaudio.com/forums/solid-state/164756-p3a-comparison-table-long-34.html
http://www.diyaudio.com/forums/solid-state/164756-p3a-comparison-table-long-34.html
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hi all,
i have made a layout for ESP P3 (not P3A), trying to minimize the size with mostly through hole components. the smd cap is optional as per the ESP website.
pl remove this post if this is not allowed.
prasi
My considerations for this design of P3 are as follows
1. R6, R5 T2 closely connected.
2. Feedback from center of o/p.
3. Decoupling close to o/p pins ( not nearly there).
4. Star grounding
The design does not require any heat sink for small signal transistors as per esp pages.
Bias servo works as designed in practice very well. This is again from esp pages...
So really appreciate some comments.
Not too sure regarding placement of zobel..is it correct?
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Hi Ian,
if your comment was meant for me,
1. there are no PCB's available for "P3". I agree "P3A" is current amp for which PCB's are available and there is no re-engineering required .
2. since P3 is a simple amp, the layout for P3 was meant as a learning exercise and for discussion. If this is not allowed, I wont post anything more here regarding ESP projects. This, I stated even in my first post of layout..
reg
prasi
Hi prasi. No I wasn't directing anything at any individual. I'm just a big fan of Rod Elliott's who has been to my house on several occasions and me to his! I contributed the Patents section to his site and respect his contribution to DIY very highly. He deserves the utmost of respect here IMO. I see the attempted redesign of his boards and the posting of layouts as a big insult to him. That said, I am not speaking for him and I'm certainly not the "Thought Police".
To prove I am no troll, here is my P3B made from a bisected P3A PCB. It's "all PSU":
I use it to drive tweeters only. It has a P39 soft start and P33 speaker protection all with original PCBs from Rod.
No agro. Just the utmost of repect for someone that I like.
No more to say.
To prove I am no troll, here is my P3B made from a bisected P3A PCB. It's "all PSU":
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I use it to drive tweeters only. It has a P39 soft start and P33 speaker protection all with original PCBs from Rod.
No agro. Just the utmost of repect for someone that I like.
No more to say.
Never i said about ESP projects reverce engineering.
Reverse engineering is about alex mm PCB.
I can't see any problem, circuit diagram published at Elliot's site for free.
My layout it's not the same as ESP ,it's not a copy /pasteNever i said about ESP projects reverce engineering.
Reverse engineering is about alex mm PCB.
Regards,Alex
I know this,your pcb is quite different and you haven't post this pcb for home etching. This is the reason for reverse engineeringMy layout it's not the same as ESP ,it's not a copy /paste
Regards,Alex
Is it something wrong
Why you are
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keep your cool people,
Rod Elliotts P3A design is always a controversial one and it sounds very good too, the way I see things, files that are being uploaded via the worldwide web community, will always be copied and reproduced (be it for product advertising or just for share). Even if you restrict these files by means of password protection nor copyrights, some people will just ignore these matter while others has the skill to get through this wall of protection and steal/copy your files. This is inevitable and theres no stopping them. The web is a harmful tool for harmful people, a harmless tool for harmless people.
I built the P3A and created my own PCB lay out as a personal preference and not meant to rival ESPs works nor create discomfort to Rod Elliott. I see my work as a "curiosity" to the P3A, the design of course is owned by Rod Elliott.
Rod Elliotts P3A design is always a controversial one and it sounds very good too, the way I see things, files that are being uploaded via the worldwide web community, will always be copied and reproduced (be it for product advertising or just for share). Even if you restrict these files by means of password protection nor copyrights, some people will just ignore these matter while others has the skill to get through this wall of protection and steal/copy your files. This is inevitable and theres no stopping them. The web is a harmful tool for harmful people, a harmless tool for harmless people.
I built the P3A and created my own PCB lay out as a personal preference and not meant to rival ESPs works nor create discomfort to Rod Elliott. I see my work as a "curiosity" to the P3A, the design of course is owned by Rod Elliott.
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