Flexible HT supply

The return of the Jedi

Time has come when breadboarding and HT is not longer an option. With a baby around, I was forced to remove most of the valve equipment. However, the return of the Jedi is closer than you expect. With very little time, albeit at continuous pace when I get a free 30min here or there every weekend, I keep very focused on my objective. The 814 SE monster amp is close to retirement (probably before Christmas) and although I have a fantastic LME amp already working, I need to get the valves back on the scene providing I can prove I’ve complied with “heath and safety” – as my wife well put it.

Well, I had a nice attempt of a wooden frame made out of pine wood. Yes, I’m really bad at woodworking but I’m getting better. The top plates are 4mm thick. I have added a nice set of 2 100mA meters at the front of the frame. A 300VA custom-wounded multi-tap HT transformer from JMS which gives me full flexibility from 100 to 500V in 25V steps. The supply is choke input (LL1638) and filtered with a set of nice 50uF oil caps and 20H chokes. Damper valves used with some nice SiC to form a hybrid rectifier.

Top plates are protected with paper before drilling!

This looks to be quite neat in my view!

The idea is to use this supply for my new 4P1L PSE, 300B and DHT Schade experiments with 6P21S/47 and 1624 valves. A lot planned and so little time for this unfortunately.

Cheers, Ale