OT - Fender 50W Blackface Poweramp

[jimmy]

i found this one in my schem library and i thought it might make an interesting project in the future. i was wondering how you would set up the power supply part if you were to use the back-to-back transformers method.

thanks
Jim

[jrc4558]

I think you wouldn't get away with less than 400V B+ for plates for typical Blackface kinda PAmp.

[Jim Jones]

Hi Jimmy,

You'd need a lot more current than two little filament transformers could provide to power a pair of 6L6's or EL34's.  There are a ton of replacement Fender/Marshall transformers available as well as a whack of aftermarket models.  And don't forget Hammond for great quality-to-price ratio.

Jim

[jimmy]

ahhhh thanks. what kind of transformer would that be? im a little unclear, as it isnt marked on the schem.

thanks
Jim

[Peter Snowberg]

It's a custom transformer so if you search for something like "Fender replacement transformer", you'll find your options there.

You want something like this unit from http://www.tubesandmore.com/ (Note: This unit has a U.S. mains voltage primary)

The Super Reverb runs the tubes at very high voltage.... I wouldn't go over 325-0-325V if you're using a tube rectifier, or 300-0-300V if you're using a solid state rectifier. Of course if you're using a solid state rectifier you won't need the 5V winding on the secondary side.

If you want to use an off-the-shelf Hammond transformer, look at the 370HX or 372JX (universal primaries). I like http://www.angela.com for things like this.

Because of the weight, I would imagine you're better off going with a local source.

Take care,
-Peter

[jrc4558]

Hey, use a Hammond!
It's Canadian  generally chaper and very reliable. As for the particular model - you can ask at www.18watt.com or at www.firebottle.com

Take care!

[jimmy]

thanks guys!!

im sure ill update you if i ever decide to give this one a go, which im sure i will.

cheers
Jim

[puretube]

http://www.turnstyle.com/nsc/catalog.asp?raster=F663.0x73D89A05C778831C.0B99.0.43FC&category=transformers