Salutations! And a pic of my current SE amp project

[dividebytube]

hopefully no mistakes here:



A look at the signal schematic shows nothing too exciting. The feedback resistor for a 4-ohm output transformer is 6.8K. For an 8-ohm secondary, increase the value to 8.2K.



6L6GCs, KT66s, 807s, 5881, etc can be used if the voltage doubler circuit is skipped. 6J7 or 6SJ7 tube will be used instead.

[castellu]

Hello,

what a nice project !

What is the major sonic difference compare to your previous EL 156 SE ?
(what was the output power of this EL 156 ?)

Thanks
B r u n o

(from France...)

[dividebytube]

they actually sound quite familiar - same front end - though the EL156 had more power reserve on tap. It's a big pentode with a 50W plate dissipation, but with the Chinese quad I bought, two of them eventually developed shorts on the screens. After awhile the amp got changed to use 6550s. But at the voltage/current I ran the EL156s, maybe 15-18Ws of single-ended power? The original Telefunken 'spec sheet lists 25W in pentode single-ended, but I would only push that if I had original German-made tubes.

But the SE 1625 amp was about $500 less to build too - so I consider it the winner!