QED A240 - DC Offset too high one the right channel - Diagnosis?

[corneliusrodes]

I have a QED A240CD integrated amplifier that I’ve owned since new. I recently replaced all the electrolytic capacitors (except main filter caps) for quality ones and also the 911/912 and 140 transistors. Also replaced the Omron G2E-182P-M relay and the RS403L bridge rectifier. All this with the intention to check the bias settings to ensure all running nicely. DC offset on the left channel is fine but the right channel is returning 80mV when amp initially turned on (I’m aware this would change once amp warmed up). The heatsink does get quite warm (approaching hot but not so much that I can’t touch). Can anyone advise where my problem might be. Many Thanks, Andy

 

[JonSnell Electronic]

The parts cannon just wasted your time and effort, not to mention your money.
Research and test. Transistors are either noisy, short circuit, open circuit or perfectly working. Don't change them for no reason!
Check C1, C2, C6 & C7. The AC coupling to the matched input pair.
If one is leaky, there will be a DC offset which is not required.

PS, if you get lost, I repair these. Send a pm to my email address; info@jonsnell.co.uk and we can see what can be done to help you.

 

[corneliusrodes]

Hi JonSnell and thanks for the input 👍. Do you mean the ones shown in this image i.e. the small red capacitors (C1 & C2 brand new) and the 2 blue filter caps (C7 & C8 the only ones i have not replaced).

 

[CSandrelli]

If those blue caps are LCR brand they will probably be at a loss. I say this because I had some from 1982 and now they are kaputt

 

[corneliusrodes]

Hi CSandrelli and thank you for the input. I'm looking to swap out the existing LCR brand. Any suggestions for replacements that will fit the A240CD?