Bogan DB-110

[Chuck H]

Nope. There's something hinky going on. Is that 490V measured with tubes in place and drawing current?

[mike60510]

I purchased a Bogan DB-110 PA for parts; however, I thought I would give it a try and see if I could get it to work. I’ve replaced the electrolytic and put in a set tubes with have no output, I’m not surprised. The source of my questions are about voltages at the transformer and out of the rectifier.

The amp has a 5Y3 rectifier. The schematic shows voltages into the rectifier should be 340 VAC and 375 VDC out. After replacing the electronics and new tubes, I measure actual voltages of 370 VAC into the rectifier and 490 VDC out. With the difference in voltage from the power transformer into the rectifier, would that explain the higher DC voltage out too?

I’ve attached a copy of the schematic. Thanks for any thoughts/comment/help in advance