The high and low side FETs are being driven by a square wave with a 50% duty cycle. The amplitude is about 10v generally which makes a meter read about 1/2 of that amplitude. That's about 5v. Placing the black probe on the source leg and the red on the gate leg will give you about 5v for high and low side.
I was hoping that someone with a diagram would help. I'm working from generic knowledge so I can't be of much help.
The DC on the op-amps in the preamp section is odd. The output of IC4 seems to agree with the input so the op-amp looks OK. The high voltage on IC5 is odd. I'd expect it to be near 0v on all inputs and outputs (not referring to thew PS pins).
The DC on the op-amps in the preamp section is odd. The output of IC4 seems to agree with the input so the op-amp looks OK. The high voltage on IC5 is odd. I'd expect it to be near 0v on all inputs and outputs (not referring to thew PS pins).
Hi,
about IC4 and IC5, as you can see from the diagram, IC5 is a buffer (pin6 and 7 together), so it is impossible that pin7 has a voltage other than pin6
Regarding IC4, if the problem is IC5 or 'before' IC5, the defect propagates to all opamps, including IC4.
My advice is to check the indicated resistors, close to RCA J3 and then remove IC10 and IC6 (input opamp) and check again the voltages on IC5 and IC4
about IC4 and IC5, as you can see from the diagram, IC5 is a buffer (pin6 and 7 together), so it is impossible that pin7 has a voltage other than pin6
Regarding IC4, if the problem is IC5 or 'before' IC5, the defect propagates to all opamps, including IC4.
My advice is to check the indicated resistors, close to RCA J3 and then remove IC10 and IC6 (input opamp) and check again the voltages on IC5 and IC4
Ppalli thanks so much for the feed back and diagram. But the amp seems to be up and running fine I changed all the op amps and the hissing was because I had a 6×9 on the output but after switching to a subwoofer there's no hissing at all and sounds clear as can be. So I think the 6x9 was picking up on switching noise but it's been fine on my sub clean and strong! But I will check those resistors suggested to be on safe side.
Please don't post in a repair thread that was started by someone else unless you are trying to help them.
Start a new thread if you need help with a repair of your own.
http://www.bcae1.com/temp/newthreaddiy01.png
Start a new thread if you need help with a repair of your own.
http://www.bcae1.com/temp/newthreaddiy01.png
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