Help needed on CCS from the PSU Guru's

[cbj591]

Good evening everyone,

I am in the process of building a 12B4 tube preamp which was changed from another design partially into the build.

The problem that I am looking at is the fact that my design/calculation knowledge is limited and I need to get the power down on the PSU that is already built without either a major tear-down or scrapping it all together.

I have attached a schematic of the PSU and a picture.

Would someone be able to help guide me through what it would take to get the voltage down to 90v and 40ma (20 per tube)?

Is this something as simple as changing the resistors? or is there a better way?

One thing I have never had experience with is a CCS. Heck, the PSU could already be one and I wouldn't be able to tell you. The last project I completed had a simple PSU that needed a lot of work just to get rid of the hum.

Any guidance would be appreciated.

Thanks
Brian

[cbj591]

oops, forgot the schematic

[leadbelly]

Er, if you're talking about a preamp using a CCS for active load, that really doesn't have anything to do with the PSU, other than you may require an additional rail. Are you talking about a CCS loaded voltage reference? You should back up and say what you're trying to achieve, and your question probably should be in the Tube forum.

[cbj591]

Leadbelly - I posted in the tube forum as well like you suggested.

Would you clarify one thing. Is this forum for Bench-top type power supplies or any type of power supply?

I just want to make sure that I keep my questions directed to the correct forum.


Thanks
Brian

[leadbelly]

Originally Posted by cbj591

Would you clarify one thing. Is this forum for Bench-top type power supplies or any type of power supply?

Any type of PS.