[soundray]

Hi, new subscriber here.
I’m looking for help on a Quad 405-2.

I occasionally do a little bit of tinkering on vintage amps, fitting new caps, etc, and agreed to look at a 405-2 for a friend. It has quite loud hiss on the left channel and hum on the right. Audio output from left seems normal level, albeit with hiss, output from the right is low level and gets very distorted when the preamp volume is raised a little. There is also a large splat when powered down.

I changed all the electrolytic capacitors, including the power caps, hoping that would cure the problems, it didn’t. My next guess was the main transistors TR9/10 so these were replaced on each board, still no change. I’m now out of ideas.

I’m very much an amateur with only a basic knowledge of electronics but I can use a soldering iron and read a digital meter, which is all I’ve needed so far. I’m hoping you guys with more knowledge and experience can offer advice on where to look next.

Many thanks
Ray