Hi, Malc

I'd suggest you to scope the 100 Hz 22v PP ... and see if it really reaches < 1.2 v level ...

In the "possibility" NOT, I'd suggest you to place a stupid 24 v 5 w bulb ( truck parts ...) just past the rectifier bridge.

You certainly noted there were no capacitors except the smoothing 22 µF ... there's an excellent reason to that !!! ... Hope you've respected it .

Ah ... last thing ... I did not see any pic in this design ...

Forum error ??? LOL

Alain