help with power supply

[ppppenguin]

Had a quick look at it. As far as I can tell from a quick look, there's the following from the mains TX:

350-0-350V to a B9A rectifier. There's a TL783 high voltage regulator which may or may not regulate the entire HT supply.

6.3V. For the rectifier heater and possible other things.

13V to silicon bridge. Probably feeds LM317 regulator. Could be a 12V or 12.6V supplly for ECC83 heaters.

Another 13V winding

[Nick]

Don't think that this is a PSU.

Suspect its a class-A headphone amplifier with FET outputs and a 12AU7/12AX7 input.

Look at the cabling underneath - that's screened cable in, stereo. Similar on the output.

Lot on Rock Grotto about modding the base design (the Bravo) - see http://rockgrotto.proboards.com/thread/5...ion-thread

The Bravo, in turn, is based on an original Sijosae idea (the MHHA - http://www.headphoneamp.co.kr/diy_sijosae) - been around for a while (2005) and very well regarded...

[tiv48]

Some interesting circuits on the second link.
Rob T

[unrealdave]

I've had a good look for the circuit diagram now but no luck. I might just put this aside for the time being, got far to much to play with.

[ppppenguin]

Having seen it in person I don't recall anything resembling an audio amplifier in it. It all looked very much like a PSU as I said in post #11.

[unrealdave]

Having seen it in person I don't recall anything resembling an audio amplifier in it. It all looked very much like a PSU as I said in post #11.

Yup - agreed - I think it is just a psu

[Dick.1]

A very common mod in guitar amps is the facility to have valve or silicon rectification switchable for differing "sounds".

Valve recto gives that "sag" so many rave on about as opposed to the silicon recto's more "dynamic" approach

My vote would be for a P.S.U.

Dick.