Full recap of the power supply and pre driver board. All new replacements for
TR603, TR606, TR605, TR625, TR626 and TR623 on the pre driver board. This has solved my popping issue that I posted in another post. Bit of a hand grenade to be sure.
My issue now is that the bias on the 2 variable resistors on the pre drive board has very little effect on the erratic behaviour of the DC voltage. The amp actually sound just fine. No distortion, not loss of signal. I am thinking that the problem is on the pre driver board. I don't think is the power supply. Perhaps the remaining transistors need to be yank.
Please jump in if any of you knowledgeable guys got a fix.
I have just got a Tek 2225 oscilloscope, but this will not be up and running until I get some recos on a signal generator. That's for another post:)
Thanks.
SCHEMATIC HERE!
Harman Kardon 930 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine
TR603, TR606, TR605, TR625, TR626 and TR623 on the pre driver board. This has solved my popping issue that I posted in another post. Bit of a hand grenade to be sure.
My issue now is that the bias on the 2 variable resistors on the pre drive board has very little effect on the erratic behaviour of the DC voltage. The amp actually sound just fine. No distortion, not loss of signal. I am thinking that the problem is on the pre driver board. I don't think is the power supply. Perhaps the remaining transistors need to be yank.
Please jump in if any of you knowledgeable guys got a fix.
I have just got a Tek 2225 oscilloscope, but this will not be up and running until I get some recos on a signal generator. That's for another post:)
Thanks.
SCHEMATIC HERE!
Harman Kardon 930 | Owners Manual, Service Manual, Schematics, Free Download | HiFi Engine