What's a good 6L6 bass amp build?

[Randall]

I want to build a no frills, straight ahead 6L6 bass head for a deep blues duo. P bass with flats emulating an upright at gig volumes. Where should I look?

[bob p]

What kind of stage volumes are you talking about? I'm guessing that you might not be needing all that much.

A lot is going to be determined by the speaker/cabinet setup. With a pair of 6L6 you could end up with a Fender Bassman type of circuit at one end of the spectrum, or an Ampeg B-15 at the other end of the spectrum.

[Randall]

Yeah, not a lot of volume, just a bass and an acoustic guitar. I have a 300w SS rig for when I need power, but that is too much for this application, which is a pre-war blues duo. I actually have a real '65 B-15, but I'm not keen on gigging with it. Plus, my back prefers separate cabs and heads. And, I want it to look retro. One channel, one input, vol, treble, bass, one 8 ohm cab.

[big_teee]

I want to build a no frills, straight ahead 6L6 bass head for a deep blues duo. P bass with flats emulating an upright at gig volumes. Where should I look?

Marshall JCM800 1986 Circuit.
http://www.ceriatone.com/images/layo...sCeriatone.jpg
Put KT88s in it, and you would have 50+ Watts.
Put EL34s, or 6L6s in it.
Depending on the OT used tune it however you want.
T

[bob p]

Yeah, not a lot of volume, just a bass and an acoustic guitar...
I actually have a real '65 B-15, but I'm not keen on gigging with it. Plus, my back prefers separate cabs and heads. And, I want it to look retro. One channel, one input, vol, treble, bass, one 8 ohm cab.

Well, if you've got a real B-15 then you know what the B-15 tone sounds like. If you think that would fit the bill, then I'd just build a B-15 head and a separate cab.

Right now, I'm thinking about doing exactly that. That is to say, it's on my to-do list, behind a few other projects that are already in the queue. I'm thinking about building a B-15 head in a Marshall-type cabinet (chassis on bottom, tubes on top), and mating that with something like an Eminence Beta 15 in a porta-flex sized enclosure. That should get you real close to vintage B-15 tone without having to drag around vintage gear.

I'd forget about bigger tubes like 6650. I'm thinking that a small 6L6 head with high output impedance, putting out only 25-30W should be plenty of power for that type of application.

[Randall]

I think I want to do a single channel B-15N. Upright, Marshall style chassis with detachable wooden head cab. Is there a layout available for this? Or must I dive into my first layout attempt?

[loudthud]

Kevin O'Connors TUT 3 (I think) book has a layout for a single channel B15. He won't allow it to be posted here, naturally he wants to sell you a book. Do a search here for "B15 layout" and look through the threads.

[John_H]

If you want to go all octal, you could build a 5C5.

[Mick Bailey]

Or a Sunn 200S with 6L6 instead of KT88.

[bob p]

I think I want to do a single channel B-15N. Upright, Marshall style chassis with detachable wooden head cab. Is there a layout available for this? Or must I dive into my first layout attempt?

I haven't seen a specific layout diagram that adapts the B-15 layout into a Marshall style layout, though I don't think it would be significantly different from the original B-15 layout. I'm thinking that if you've got a genuine B15 specimen to copy, then doing a layout should be a no-brainer.