Frank's 6sn7 preamp

[losacco]

I’m looking for a tube rectified power supply for Frank,s 6sn7 preamp. I have done a search and have come up empty. Parts I have, Hammond 270BX(550V-50mA), 5u4gb rectifier. I would like to try designing one myself but don’t know where to begin.

Any help on a power supply for this preamp would be appreciated. Mean while I'll keep searching.
Thanks

 

[mikvous]

What's your B+ target? If I remember well it should be around 250 V.

 

[losacco]

yes, 250v b+

 

[mikvous]

So your trafo is 275V AC center tap @ 100 ma?

 

[losacco]

275V AC, 50mA

275V AC, 50mA

 

[mikvous]

Ok, I believe it's enough.What I've done is a simple CRC (220 uf-50 ohm-220 uf) and after that Salas HV shunt regulator @ 30-40 mA with amazing results.You must have at least 265 V before the regulator to regulate @250V.
Which version of the preamp are you building,the direct coupled or the cap coupled?
I prefer the direct coupled one.

 

[losacco]

direct coupled

direct coupled

 

[losacco]

schematic

mikvous, do you have schematic of this power supply?

 

[porkchop61]

Here's what I'm using:
http://webpages.charter.net/porkchop/tubeamp/6SN7_preamp_power_supply-Franks_ultimate.jpg
Only because it's a PT that I had on hand scavenged from an old HAM radio. Some of the cap and resistor values may have changed slightly, but it's basically the same circuit. I think I have a 100uF as the last cap now. I was trying to tune the output voltage to the 250V using the resistors. Probably a waste of power for the tranny as it was made to supply more tubes than I am now using, but again I already had it.
Mine's dead quiet with this power supply.

 

[mikvous]

Take a look at Power Supplies ,thread: Simplistic Mosfet HV Shunt Regs ,post: 1198