Kerry

Best wishes Birgir. Stay safe!

You should use a higher Hfe. What you have is ok, but if lower R39 to around 40k to 50k. Highest value that is stable.

Depending on the Hfe of Q23, you might need to lower R39. This could cause instability / oscillations in that area. If you can hear the amp without the headphones in, then it's oscillating. I agree that most multimeters should be able to pick this up (though maybe not accurately). If the amp is wildly oscillating and has very high voltage swings it could possibly damage the amp.

Happy Birthday, Todd

Happy Birthday! Enjoy

Happy (very) belated birthday, Jose

I had some of these made up. PM me. They are a drop-in replacement for the Keystone part, but with a 6mm opening

Happy belated birthday, Chris. Just saw this now, but wanted to wish you well

Happy (very) belated birthday, Rob

Happy Birthday Antonio! Enjoy

Happy belated birthday!!

Happy Birthday, Birgir!!! I hope you had a wonderful day

Congrats! Awesome news

Thanks everyone. Very much appreciated. I spent the day with my family including my granddaughter who just turned 5. What a delightful day

Thanks Mark. I'm going to check them out.