SE + PP amp

[joshdfrazier]

I really do love the sound of a SE 5-6w amp, but of course, they aren't loud enough for gigging unless you are playing a venue with a legit PA, which isn't always the case on tour. Got me thinking, has anyone tried to build, say, a SE using just a 12ax7 and el84/6v6, then used a step down xfmr to bring it down to line level into a 50-100w poweramp? There would be alot of iron in this amp to be sure, but is it possible?

[Scumback Speakers]

I'm not sure if doing that would work but my solution is this...

Single Ended dual 6V6 Class A amp into a BadCat Unleash. The amp is a 1958 Gibson Gibsonette. One 12AX7, the 6V6's are running in parallel single ended (on for the full cycle of the power tubes), and one GZ34 rectifier tube. I've put in a Hammond SE output transformer and Fender Deluxe Reverb power tranny. Somewhere around 360-375 on the plates using JJ power tubes, although good NOS or ANOS is a little nicer sounding.

[img568]http://www.scumbackspeakers.com/jimspic ... eashed.jpg[/img]

With the Unleash I set the amp at 8 ohms, feed the speaker output to input of the Unleash. That creates 100w of Class D solid state power that reamps the signal.

If you go 16 ohms you get 50w, at 4 ohms it's 180w. This was my solution to what I think you're trying to get accomplished.

I can tell you one thing...set to the 4 ohm tap, and hooked up to two of my 4x12 cabs loaded with M75-PVC 65w is the bomb.

[joshdfrazier]

Yeah, that is a good idea, and what I was aiming for. I guess in the end you would just be building a preamp, two power amps and an attenuator. If I do decide to attempt this build, an SS poweramp might not be a bad idea...

[xtian]

I built a 25w SE bass amp for a client, using a line-out to 300w ss power amp when big volume is needed. Amp came out great as a standalone guitar amp, and happens to sound great with bass!

https://tubeamparchive.com/viewtopic.php?t=22434

[LeeMo]

This:http://www.guytron.com/#!our-desgin/cjg9

and this:http://www.badcatamps.com/unleash.html

[Stevem]

I`ve had a notion to build a duel KT120 SE amp for too long now.In fact all I need is the OT.

[didit]

... anyone tried to build, say, a SE using just a 12ax7 and el84/6v6 ...

The Garnet Herzog from mid '60s was essentially this. A "Champ" head with a dummy load plus a line-out. One could plug into an external speaker. There have been a few versions over the years. Schematics are around via search and there are even a few build threads here on TAG.

Best .. Ian

[Firestorm]

I`ve had a notion to build a duel KT120 SE amp for too long now.In fact all I need is the OT.

That OT will probably weigh as much as the whole rest of the amp

[Scumback Speakers]

The OT's for single ended amps are HUGE.

The one used in my 25w quad 6V6 design is the same size as a Marshall 50w 1987.

If you were to get one to handle 120w, it's going to be Godzilla sized.

[teemuk]

If it's going to be reamped then personally I don't see why the need for power tubes, pentodes, yes, transformers yes, especially in a SE design, but why power tubes? There are small signal pentodes too, ones that don't generate output power in order of watts but milliwatts. If you don't build a high-ish power amp reamped by a high power amp you can go easier with the loading requirements, component sizes, costs, weights, and all.

And as always, this isn't really first time the re-amping idea is brought out. Your major obstacle is not going to be how to reamp something that is essentially a gain stage but convincing that gain stage that it is driving a real speaker load, as that will have major effect on its tone and realism as a "tube power amp". If you want it to interact with the speakers you are actually using then you need to go the extra mile.

And after that I'm not overly sure why you would want to reamp it with something that is probably going to change the tone alltogether, or most likely is designed from principles of doing so. The decision to use a class-D, and most importantly transparent, power amp in that light seems rather on point.

And once you overcome the said issues you probably figure out Korg did it with the Valve Reactor line already more than 10 years ago.