Hello Guys
I've build a P68, the sub woofer amp form Rod Ellitot, i had purchased the pcb and it's verry easy to assemble
but i have three problems:
1- very low output power, nowhere near the 250w, barely make my subwoofer move
2-the driver transistors (Q4,Q5,Q6) doesn't heat, this is a class A driver, they should heat even with no signal
3- the Quiescent Current, mesurring R16/R17 i get 200mv = 50ma, this should be 30=mv to 80mv =16ma
i already checked all the board with a magnifier glass, replace Q1 to Q6 3 times, checked all the resistors, desoldered all output transistor and checked, re-done all the soldering
i have no ideia what more to do, here the schematic
I would apreciate any help
Thanks
Pedro
[IMGDEAD]http://sound.westhost.com/p68-f1.gif[/IMGDEAD]
(if it could help e have pictures of the amp here, just let me know if it will help and i post them)
I've build a P68, the sub woofer amp form Rod Ellitot, i had purchased the pcb and it's verry easy to assemble
but i have three problems:
1- very low output power, nowhere near the 250w, barely make my subwoofer move
2-the driver transistors (Q4,Q5,Q6) doesn't heat, this is a class A driver, they should heat even with no signal
3- the Quiescent Current, mesurring R16/R17 i get 200mv = 50ma, this should be 30=mv to 80mv =16ma
i already checked all the board with a magnifier glass, replace Q1 to Q6 3 times, checked all the resistors, desoldered all output transistor and checked, re-done all the soldering
i have no ideia what more to do, here the schematic
I would apreciate any help
Thanks
Pedro
[IMGDEAD]http://sound.westhost.com/p68-f1.gif[/IMGDEAD]
(if it could help e have pictures of the amp here, just let me know if it will help and i post them)