HD3S hum problem.

[Rhod]

Originally Posted by John Caswell

Hi Rhod,
Just as a silly, please measure the heater voltage on the valve base pins 4-5 and report back here.

John

Thanks John, will do.

[Rhod]

Richard, I'm wondering if I might have 'cooked' one of the diodes (C3D04060A X4) or caps due to lack of soldering experience. I'll check for dry joints as you suggest, then look at replacing those one at a time. Thanks everyone for your input, I'll do some homework and get back to you. Merry Christmas.

[bob orbell]

Rhod, the data sheet for the diodes may help you, it will state max heat and time for soldering that the component will withstand, if you are new to soldering avoid silver based solder and use flux past, not bakers acid flux, clean PCB and component legs with scotch bright before starting, done correctly you will see the solder get sucked into the joint, a blob is not good. Bob

[A Stuart]

A cousin of yours? (3.40 minutes in) https://www.youtube.com/watch?v=I1IM37OY0Kg