AC15 transformers

[jim]

I want to build Sluckey's AC15. I have sitting around a 272FX power transformer that provides 600V CT...a bit more than the spec 270FX with 550V CT.  I have never build an amp with EL84's--will this over voltage still be OK?  I also have a little tweed style OT from a Blues Jr. and a OT from a Deluxe Reverb--which would sound more authentic? Or should I just suck it up and buy the correct iron?  Jim

[vampwizzard]

272FX is good for a pair of 6L6's.. or 30Watts. Youd be closer to AC-30 territory vs AC-15. the deluxe reverb OT would be better than the blues jr OT.. but idk if having such overpowered iron would persuade you to change what amp you'd like to build.

[kagliostro]

People that want or must use a PT with a Hig Voltage a bit in excess for EL84 tubes can use russian 6P14P (6P14P-EV better) without be disappointed

http://www.tubes.ru/techinfo/HiFiAudio/6p14p.html

Franco

[jim]

Thanks for the suggestions.   Jim

[st]

People that want or must use a PT with a Hig Voltage a bit in excess for EL84 tubes can use russian 6P14P (6P14P-EV better) without be disappointed

+1 on the 6P14P-EV. Great tube. Milspec is of superior quality and easy to find, not too expensive either (at least in Europe). Takes up to 500V.

[vampwizzard]

duly noted on the higher voltage el84's. Gonna take a look at them myself for my el84 hammond conversions which seem to cook a little bit.

The problem here is more likely that undercurrent will raise the voltage even higher. Preamp wise youll be more than fine with any of the AC style circuits, youll run into more problems when you get into output tubes. Unfortunately, if you change the output impedance and power handling you may need to get a better suited output transformer.

With that PT you could make an AC15 style amp but with two EL34s. Go wild with your imagination. thats thalf the fun.

[jim]

I will try some E84Ls which I found a bit harsh in other amps.  I could use a 5Y3 or 5U4 to drop it a bit more.  I also have a 25W 30V zener that I might try on the center tap to mellow the voltage a little further for regular  EL84's.  I am going for small and low power this time.  Thanks, Jim

[pdf64]

...I am going for small and low power this time...

Definitely best to get the right iron for the job then, even with a 5Y3, the 272FX is probably going to be way too much for EL84 type tubes in hot AB cathode bias.