EL844 Amp Based on 5f6a?

[The New Steve H]

I hope this doesn't mean I'm trying to design an amp I already hate.

[sliberty]

I don't know exactly what you are looking for, but I can tell you that I love my Rockets. I've built two: one is a traditional head in a wooden cab, and the other is a 4x12 combo in a Peavey Classic 50 cabinet. The Rocket has fabulous cleans, glorious edgy "almost" cleans, and a wonderful smooth break up. I prefer the head/closed back cabinet combination, but the 4x10 combo rocks too. If you install a VVR, you won't need to deal with half power switches, etc. It is very effective and quite transparent in a Rocket.

[Zippy]

I hope this doesn't mean I'm trying to design an amp I already hate.

I'm already hating your next amp.

But I'm an engineer...

[The New Steve H]

I'm wondering why I hate the AC30, when it's so similar to what I want to build. The Rocket clips I've heard sound good.

[sliberty]

Sorry if this is covered at the beginning of this thread, but you have the AC30's at church and they are too loud or something like that, right? But I don't remember you mentioning that you don't like them, or why. Can you put it into words?

[Zippy]

I'm wondering why I hate the AC30, when it's so similar to what I want to build. The Rocket clips I've heard sound good.

Take a look the the circuits, determine the differences, and "tweak" one of the AC30s into a Rocket. I did the exercise a few years ago comparing AC30, Fender Bassman, Marshall... and there aren't that many differences. All can be good amps.

or...

You may not like it because of who's playing 'em.

[The New Steve H]

I played one of the AC30s at home. I think this is an AC30CC2; I may have the number wrong. It's Chinese.

Anyway, it seemed like there was a big fluffy sweater between me and the sound, and it had no warmth and no edge to it.

I'm not fooling with the AC30s any more, apart from making them function again when they quit.

I don't know what gives the Voxes that sound. I just skimmed an Aiken Amps thing about the AC30 not being a true Class A amp, so I guess it can't be because they're single-ended.

All I really wanted to do was create a 5F6A, with all the inputs and controls, but I wanted a lower output so I could turn it up a little more, and I wanted to try EL84s or EL844s. Now that I'm getting deeper into it, I'm inclined to forget about lower output (since the 5F6A sounds good on "1") and just make a Bassman with the desired output tubes. I guess it would come in at around 35 watts. I would use that weird PT I found, plus a regular Bassman OT. I like the PT because it gives me so many options if I hate the original effort.

I like the Little Wing, but it lacks some of the doodads the 5F6A has, and it has 6MB8 tubes. I have heard EL84 amps that I really liked, so I wanted to give them a try.

[Zippy]

I don't know what gives the Voxes that sound. I just skimmed an Aiken Amps thing about the AC30 not being a true Class A amp, so I guess it can't be because they're single-ended.

Say what? You need to slow down if you hope to learn anything - the Aiken article is worth reading slowly a couple more times.

The AC30 is not single-ended. It's a push-pull amp that is running too high B+ to operate in Class A mode.

Arghhhhhhhhhhhh... I gave away the punch line.

[sliberty]

OK, that helps. So let me say "this about that"

Rockets are bright, responsive, chimey, and lively. You will NEVER perceive that a blanket is covering the amp unless it is not wokring correctly. It will sound VERY different from the AC30 experience you have described.

There may very well be something wrong with AC30CC that you tried, but regadless, a Rocket won't sound like that.

[The New Steve H]

The AC30 is not single-ended.

That's what I said. "It can't be because they're single-ended," because they're NOT single-ended. I wasn't too clear, but that's what I meant.

Rockets are bright, responsive, chimey, and lively.

Let me ask you this: can you get a good sound on "1" the way you can with a Bassman? If so, I'm sold. I don't gig, so if it's only useful in a big venue, I won't get much use from it. I also like the way the Bassman responds to pick pressure, and I like the generous bass.

I appreciate all the help. I think I'm getting a clue here.

[sliberty]

I find that the Rocket sounds best above 3 on the volume pot. However, if you are thinking that this will be too loud, that is why I install a VVR on my Rocket builds. With the amp set to 4-5, I get wonderful cleans, and I turn the overall level down with the VVR.

As for bass response, the Rocket can sound pretty beefy, especially with a 2x12 or 4x12 closed back cab. But even my 1x12 closed back has great big bass response. I'[ve never owned or played through a 5f6a, but I did build a JTM45 (very similar circuits), and found that the amount of bass available was just silly. I had to keep the bass pot on 1 or zero most of the time. The Rocket is not as bass heavy, but that is a good thing. Yet tehre is plenty of bass on tap.

[Zippy]

Build an octal Rocket (octal outputs) and run cathode bias so you can swap in/out 6V6, 6L6, etc.

Deja vu all over again...

[sliberty]

By the way - that 6BM8 based Bassman looks interesting, and I might uld one at some point But I love my Rockets.

[The New Steve H]

Okay, so I guess I can go three ways?

1. Rocket with VVR.
2. Rocket with PPIMV.
3. Bassman preamp/Rocket output

I would really like to keep the normal/bright inputs.

At least now I have some idea what hardware I'll need.

[ToneMerc]

All I really wanted to do was create a 5F6A, with all the inputs and controls, but I wanted a lower output so I could turn it up a little more

Brotha, you love to reinvent the wheel. Why don't you just build a 5F6A and use two JJ 6V6's?

TM