Please comment my pcb P3a - Page 6

dexter · 25th January 2007, 12:31 AM

I;m not quite sure about the oscilation, I don't have a scope to check it.

I'll change the driver tr from BD 139/140 to SA968/SC2335
hopefully in this coming weekend.

any other suggestions are welcome

beboni · 17th February 2007, 01:14 PM

[QUOTE]Originally posted by dexter
[B]I;m not quite sure about the oscilation, I don't have a scope to check it.

I'll change the driver tr from BD 139/140 to SA968/SC2335
hopefully in this coming weekend.

any other suggestions are welcome

greetings dexter,i have just built p3a amp with that pcb layout and bd139/140 drivers and mjl4281/mjl4302, and i could say that i am preety disapointed because the sound is the same as you described.

no bas,no dinamic{flat/not interesting}muudy or no details,iam sure the problem lies in bd139/140.did you changed these driver tranies,any changes in sound?

tcpip · 18th February 2007, 02:45 PM

Quote:

Originally posted by beboni
greetings dexter,i have just built p3a amp with that pcb layout and bd139/140 drivers and mjl4281/mjl4302, and i could say that i am preety disapointed because the sound is the same as you described.

no bas,no dinamic{flat/not interesting}muudy or no details,iam sure the problem lies in bd139/140.did you changed these driver tranies,any changes in sound?

I have built the P3A on Rod Elliott's PCB (a friend had bought a couple from Rod) and using the parts Rod had listed in his notes for the P3A. I am using 1943/5200 OPS devices. The rest of the devices are all as per his notes. I am most certainly using BD139/140, and I'm happy with the sound.

On a related note, it's a bit difficult to understand what "I'm happy" or "the sound is muddy" means.... it's all subjective opinion. I don't know how to tackle this problem, however. We all just have words to interact with, on these forums.

BTW, if I remember right, your input cap is a little smaller than what Rod had recommended, and your quiescent current is a lot higher than what he recommends. So, maybe you could try fixing those before replacing devices?

adey · 8th June 2012, 08:36 PM

Can anybody tell me the value of C8 and C9 of ESP P3a?

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25th January 2007, 12:31 AM	#51
dexter diyAudio Member Join Date: Apr 2001	I;m not quite sure about the oscilation, I don't have a scope to check it. I'll change the driver tr from BD 139/140 to SA968/SC2335 hopefully in this coming weekend. any other suggestions are welcome

17th February 2007, 01:14 PM	#52
beboni diyAudio Member Join Date: Oct 2005	[QUOTE]Originally posted by dexter [B]I;m not quite sure about the oscilation, I don't have a scope to check it. I'll change the driver tr from BD 139/140 to SA968/SC2335 hopefully in this coming weekend. any other suggestions are welcome greetings dexter,i have just built p3a amp with that pcb layout and bd139/140 drivers and mjl4281/mjl4302, and i could say that i am preety disapointed because the sound is the same as you described. no bas,no dinamic{flat/not interesting}muudy or no details,iam sure the problem lies in bd139/140.did you changed these driver tranies,any changes in sound?

8th June 2012, 08:36 PM	#54
adey diyAudio Member Join Date: Dec 2009	Can anybody tell me the value of C8 and C9 of ESP P3a?