2xEL34 vs. 4xEL84 vs. 2x6L6 vs. 4x6V6

[rbruss82]

I am about to begin designing a custom tube amp for a musician in my town. He pretty much knows what he wants, he is a minimalist, and he wants to use the highest quality components available. Pretty much an amp builder's dream!

The thing he doesn't have an opinion on is the selection of the output tubes. He wants something in the 30-40 watt range. Any of the output tube setups mentioned in the subject would get us there. I was just wondering if I could get some different opinions on how these different setups affect the operation of the amp (headroom, clarity, tone, etc.)

BTW, the customer plays blues with a lot of slide. He is looking for early breakup.

[aletheian-alex]

El84's will break up at a much lower driving voltage than EL34's. 4 of one vs 2 of the other will break up at relatively the same output volume, but with the same splitter/driver setup, you'll have more power amp distortion avaliable from the same input voltage swing from the preamp with the EL84's.

[mac1amps]

I would also vote EL84's. The inherent characteristics of those tubes are universally liked by virtually all players (including COUNTRY players). I especially like their tendency for high end roll-off when they're driven into saturation, especially when used with a Strat or Tele. It amazes me how decent these tubes can sound, even in amps that are very cheapley (i.e. poorly) made (like Trace-Elliot's for example, which have quickly become one of my LEAST favorite amp lines to have to service)

[Casey4s]

What type / style of music is your friend going to use this amp for?

What basic design are you going for? Is it to be an off shoot of a Marshall type design, Fender, Vox or something else? A ground up original design?

I think either question would make a difference in the selection of output tubes in your design.

Personaly I like a 4x6v6 design, but it seems the 4xEL84 is a popular choice here.

[Bruce / Mission Amps]

EL84s for a real blues amp? BAH HUMBUG!!
.... always was a goofy proposition in my book.

Any 4x6V6 amp would be very cool!
Fixed bias hot around >10watts each and a good 4K 40-50 watt output tranny with a 300vac@200ma PT... an easy 35watts output.
Single GZ34 rectifier tube.
Build him a 4x6V6, single channel BF Princeton with no reverb or trem and watch him drool.

[scole]

wich tubes

i agree with bruce, the fact that he wants earky breakup pretty much rules out el34's and 6l6's. however he would probably love a 5f4, i know i do. using 2 10 inch speakers and setting the bias just right will put him right in the pocket.

[soundmasterg]

You could also try a 7591 pair. With JJ and EH making them now, the cost isn't through the roof, and they sound good.

[Dutch]

You could also try a 7591 pair. With JJ and EH making them now, the cost isn't through the roof, and they sound good.

+1 on the 7591s! My favorite output tube, just edging out 6V6es....

HTH!

C ya,
Dutch