Chops54
Junior Member
I wonder if anyone can advise me. I own a pair of Transcendent Sound Grounded Grid preamps which I'm very happy with but after my son asked if he could have one of them I decided to build myself a replacement in two boxes using tag strip and point to point wiring. The power supply is a bit unusual in that it's a balanced supply using a pair of small transformers to give +200 volts and -200 volts. Each psu uses a doubler circuit to achieve around 240 volts which is regulated to 200 volts by a pair of 100 volt zeners. There's a 5k shunt on the psu output for the zeners. My problem is the shunt is getting too hot and I thought maybe the zeners were causing an issue so I lifted one leg of each zener pair and I now have something like 560 volts after each shunt. Obviously the shunts are getting hot because the zeners are having to ditch so much voltage but I don't understand why I have so much voltage in the first place. I can post a circuit diagram if a mod will allow it but I don't want to take liberties even though it is already in the public domain. Any help will be appreciated.