Low wattage, tube based *power* amp?

So looking at the whole Randall/Egnator thing, it seems like a very practical and flexible solution for the project studio guy for a lot of guitar tones at a reasonable price, combined with something like a Grendal iso cab. But there seems to be a dearth of low wattage, like 5 watt'ish power amp sections to use with them. I could buy an amp of course with a send/return but space is at a premium, and I'd prefer something in a box or a rack mountable box if such a thing exists.

I really don't see anything out there catering to what I would think would be a fairly growing market (the project studio market.) Randall only sells a 50 watt stereo thingie. You have things like the Boogie 20/20 which is still massive overkill for something like this, and stereo which isn't needed.

I can't imagine why Randall doesn't have an option for a 5 watt power section in their RM4. That would make it a no-brainer flexible project studio device.

Anyway, any ideas on this front? I'd like good quality, but relative to someone who's buying a Randall RM4 instead of a room full of Marshalls and Bogners and whatnot. So maybe $250'ish range or less?

It's a lot more than your $250, but here's probably the ideal solution for you; the Rockmod Brick:

http://www.kashaamplifiers.com/index.htm

Going into the effects loop, you can bypass the preamp. You have your choice of running one or two EL84s or 6V6s.

It's nice to see John back in business. I used a Rockmod II as my preamp for seven years; the longest I've stayed with any preamp/amp.

ew

I think you have to order it as one or the other.

One of each?

That's revolutionary! (or at least the first time I have heard of this technique)

What do they do about the crossover distortion when running both type tubes?




edit to add:

Why do they use aircraft aluminum to get a precise fit?

What is aircraft aluminum?

Is aluminum a good material to use while designing a faraday cage?


I thought aluminum was for making early Marshall prototype clones... and for making sure the chassis gets relic'ed (a.k.a. warped) when the cartage truck hits a bump and the tranformers practices the fine art of inertia.

:-)

Yes those are pairs... or more precisely even numbers.

Is this a push pull amp using two different tubes?

That's the part I would consider unusual.


edit to add:

The Egnater seemingly uses a parallel power circuit... which is pretty unorthodox... I'm fascinated and will try to learn more.

best,
mike

ORIGINAL: mike_mccue


edit to add:

The Egnater seemingly uses a parallel power circuit... which is pretty unorthodox... I'm fascinated and will try to learn more.

best,
mike

Boogies have done that for years; that's the whole routine behind their Simul-Class amps. You have one pair of tubes running in a Class AB circuit and the other pair running in a Class A circuit.

ew

I HAD....
a Peavey JSX mini colossal amp....

5 watts.
class A.

with a recording out.

it was a nice amp, especially for the money.

now, i could get great clean tones with it....

but very, very quietly.

if this is all you need, i'd say, forego all the expense of channel switching this and that....

and go for simplicity.

if you are going to mic a speaker, the excursion of the speaker, and the way it interacts with the amp, is very important to both the feel, and the sound.

if you want stellar recorded sound, you've got to understand, that a iso box, will always sound like 'the box'.

you also have to understand, that the reason for higher wattages, is for CLEAN HEAEDROOM.

low watts, will not get you super clean tones at anything but bedroom volume.
not very useful, unless THAT is all you need.

i have a vintage 60 watt tube amp, that i now use in conjunction with a WEBER MASS LITE attenutator.

it works like a charm.

i also use combinations of mic, and the PALMER PDI-09 DI/cab sim box.
it sounds great.

so i can mic up when i want to be loud, or run strictly direct, using the attenutator to give me bedroom volume, and the palmer ties in BEFORE the attenuator, and it gets the full output sound of the amp.

this to me, is the best solution, for the compromise between controlled environment, and making use of the gear i really like.

by the way, 5 watts (like with the little peavey tube amp) is ALMOST loud enough, when fully driven, to play with a band.

so "low watts", is only really relevent to your gain structure.

low watts, will not get you super clean tones at anything but bedroom volume. not very useful, unless THAT is all you need.

But that's all I need, since this is for a studio, and it'll be close mic'd, so it doesn't have to be loud at all. The Nanohead is something I was seriously considering, 1/2 watt, but the RM4 would provide a lot more flexibility. If I could find a good quality 2 or 1 or 1/2 watt power amp section, I'd be plenty happy with that.

I'm in an apartment. I MIGHT be able to get away with a 1/2 watt power amp without an ISO box, but even that can be pretty loud. If I do need the ISO box, then I might as well get a somewhat higher output one for a little more headroom.

The Grendel doesn't sound terribly boxy. It has like 6" of insulation in the lid (the speaker fires into the lid.) It does cut down on low end, but generally that's not a bad thing for recording, since it'll be close mic'd.

Biasing doesn't even come into the question when you're talking low wattage like you are. All the amps putting out low wattage like that are Class A; there isn't any crossover, hence nothing to bias.

Hmmm... So why do so many of these low wattage amps brag about being auto-biasing, and allowing you to plop in many different types of tubes?

I don't think that's fair to say.

A class A amp like the Fender Champ has a Cathode biased circuit. Cathode bias has been called a self biasing design since the 1930's... way before push pull came along.

I believe the critical reason to bias a push pull amp's tubes is to balance the output of each tube... it's also noteworthy that AB push pull designs are intended to push the tubes harder (thats why they switch on and off to prevent overheating) so the bias sweet spot is much narrower than when working with a low output circuit.

Some amps have balance circuits and fixed bias... the bias is fixed but you can balance the two sides with a potentiometer.

The idea behind mix and match tubes in a small class A amp is that it's just not critical and definitely can provide a wide range of sound.

best regards,
mike

well, my point of having a super low wattage amp, and putting it thru a speaker, was more about the fact that if you don't move any air at all (speaker excursion), it's gonna sound pretty wimpy.

that's why you don't see pros using that type of setup very often.

character of sound (when live micing) comes as much from the room sound, as from the amp and speaker itself.


inside of a box, has almost zero character.

the magic 'MOJO' of tone, typically comes from all factors:
the cabinet
the choice of speaker(s)
the head
whether you're running the head hard and loud enough, to be in the 'sweet spot'
the interaction of the room acoustics


then, the 2ndary things, like the guitar, the player, the cables/pedals, etc.....


the idea behind getting 'mojo' out of a low watt class A amp, still revolves around pushing a speaker properly, typically at a still loud volume, and choosing a speaker that is at it's optimum working level, to actually get a 'tone' out of it.

look at the Emery BABY for this kind of multi tube, multi tone setup....

but really, these types of amps really only have one sound, and that's the sound that's inherent in your guitar.

purist love these types of amps that react to each guitar in your collection.

the amps themselves, do not have a wide range of sound, and that is their forte.

i say there are no CHEAP 5 watts amps...
that's not true.

the epiphone amp fits that bill.

but i can't stand the sound of it.

so, i wouldn't own one......

ORIGINAL: mike_mccue

I don't think that's fair to say.

A class A amp like the Fender Champ has a Cathode biased circuit. Cathode bias has been called a self biasing design since the 1930's... way before push pull came along.

But- that's my point, Mike. All your cathode biased amps are self biasing- they don't need traditional crossover biasing. To use that as a sales pitch when it's inherent in any amp design of that size is self-serving IMO...

ew

Eric does Simul class have dual speaker outputs... the part I'm not understanding is how the two parrallel circuits could drive a single speaker simultaneously.

I'm at the Mesa site and have not found the info about that yet.

Ahh, so we do agree... that's not revolutionary.

But this idea of placing two different type tubes in a single push pull circuit, as I infer the Kasha does, (after reading all the info I could find at the site) and providing a single speaker output does seem revolutionary to me.

Maybe someone did it on a Williamson in the fifties ;-) but I never heard of this idea... so it really caught my attention.

When you said the Kasha was similar to the SimulClass I thought maybe I had never understood how the SimulClass worked.

best regards,
mike

I thought you just said the Simulclass doesn't sum but rather is dual core with seperate output channels?

Now I'm confused again? :-)

I've posted a question about the possibility of summing on another forum that I get help at on occasions.

best regards,
mike