best 2 x 6L6 circuit?

[stephenhartley]

I'm looking to build a 2 x 6L6 amp and I want to use a simple circuit. I've already built a 5E3 with a brownface tone circuit - can I simply upgrade the transformers and the cathode resistor on this circuit or do I need to upgrade anything else? Is there a better circuit?

[Bruce / Mission Amps]

I'm looking to build a 2 x 6L6 amp and I want to use a simple circuit. I've already built a 5E3 with a brownface tone circuit - can I simply upgrade the transformers and the cathode resistor on this circuit or do I need to upgrade anything else? Is there a better circuit?

Yes. But a better choice and change with some muscle behind it... black face Princeton with cathode biased 6L6s....

[stephenhartley]

Thanks - the 5E3 I just built is the best sounding amp I've ever heard (used your grounding suggestions & it's very quiet) - keeps up with the loudest drummer ever and the second channel is fine for vocals at rehearsals - using a reconed 60s Goodman Audiom speaker which has a big heavy Alnico magnet.

Want to build a 2 x 6L6 with 4 X 8" speakers in order to handle the double bass that we've just bought - I remember you saying that you had built these before and called them 'bassboy' or something similar. I'm thinking that if I can switch to fixed bias for bass use and cathode bias for guitar use + a handy second channel for vocals or keyboards or whatever, then it's going to be pretty much the ultimate practical amp to rival a bassman or a vox AC30, but just a bit more compact and portable.

[Bruce / Mission Amps]

Thanks - the 5E3 I just built is the best sounding amp I've ever heard (used your grounding suggestions & it's very quiet) - keeps up with the loudest drummer ever and the second channel is fine for vocals at rehearsals - using a reconed 60s Goodman Audiom speaker which has a big heavy Alnico magnet.

Want to build a 2 x 6L6 with 4 X 8" speakers in order to handle the double bass that we've just bought - I remember you saying that you had built these before and called them 'bassboy' or something similar. I'm thinking that if I can switch to fixed bias for bass use and cathode bias for guitar use + a handy second channel for vocals or keyboards or whatever, then it's going to be pretty much the ultimate practical amp to rival a bassman or a vox AC30, but just a bit more compact and portable.

Correct, the Bassboy... it was like a 6V6GT version of a tweed Bassman with fixed bias, a NOS 5U4GB, I think used reissue Deluxe Reverb power and output transformers, four speakers wired series/parallel to get 8 ohms, a 12AY7 first preamp tube and the phase inverter was slightly reduced in gain so as not to pound the 6V6s too hard.

[soundmasterg]

Thanks - the 5E3 I just built is the best sounding amp I've ever heard (used your grounding suggestions & it's very quiet) - keeps up with the loudest drummer ever and the second channel is fine for vocals at rehearsals - using a reconed 60s Goodman Audiom speaker which has a big heavy Alnico magnet.

Want to build a 2 x 6L6 with 4 X 8" speakers in order to handle the double bass that we've just bought - I remember you saying that you had built these before and called them 'bassboy' or something similar. I'm thinking that if I can switch to fixed bias for bass use and cathode bias for guitar use + a handy second channel for vocals or keyboards or whatever, then it's going to be pretty much the ultimate practical amp to rival a bassman or a vox AC30, but just a bit more compact and portable.

Bass amps tend to need about three times the wattage of a guitar amp to get adequate clean tones at an appropriate volume. A paid of 6L6GC's won't be enough to get you more than about 30 watts....I would say a couple 6550/KT88's or an amp with four 6L6GC's would be good enough with a cabinet with efficient enough speakers, but anything less than that and you will not have much headroom or will get very dirty tones. If that is what you want though, go for it.....

Greg

[Bruce / Mission Amps]

I built a fixed bias 2x6L6GC with two 12AX7s, bass amp for the young son of a friend of mine.
A very simple "normal channel" Fender circuit... non reverb, etc.

Using generic Fender aftermarket power and output transformers from Magic Parts for a "Super Reverb".... it still made an amazing, dead clean 38-40 watts at <30Hz into a 4 or 8 ohm dummy load.

It sounded mediocre to OK with a 2x10 cabinet I had here, using some low cost generic Eminence bass amp speakers...
but the thing sounded really, really good using an older 8 ohm Eminence 15" PA speaker!!
So the moral... fixed bias, good transformers for more power, solid filter supply with lots of reserve and pick an efficient speaker in a good cabinet that can really get down in those low freqs with solid +98dB/W/M SPL ratings and it will be very special.

[stephenhartley]

Thanks for those suggestions. 35w or so should be plenty. I've got a bunch of Russian military 5U4GBs so will give one a try

I'm trying to get the most out the most compact lighweight setup - similar spec to a Bassman or AC30 but a bit lighter and more compact. Difficult I know, as the amount of 'umph' is proportional to the amount of iron in the transformers and speakers - hence trying 4 x 8" rather than 4 X 10". Using 4 Jensen 4 ohm P8Rs series parallel to get 4 ohm. They're the only readily available 8" alnico speakers in the UK.

I'm re-using the 4 X 8 cab that I used for my first 5E3 build and building a 2 x 6L6 chassis from scratch. I bought a sheet of 8 x 4 ft aluminium sheet from a local supplier and I've got a simple folding machine from Frosts auto so I can knock up my own chassis - bought some punches from the local tool shop for the tube bases - amazing what you can do with a few simple tools.