Rocket with normal & ef86 channel and tremolo?

[Dingleberry]

Hi.

I'm in a mood for "wreck" building.
I have a donor head chassis and a set of transformers that would be just fine for a two channel Rocket type project.
One with ef86, RT66 type preamp and one regular rocket preamp.
The donor chassis has two channels with independent volume treble and bass controls. Also common speed, depth and reverb.
I thought about ditching the reverb but fitting a cut pot there instead.
I can use the tank for my other projects.
Tremolo would be a nice feature and pot holes and markings are already there in the chassis so why not.
What kind of tremolo would fit the rocket?

I did the search and found Jackie Treehorn drawn bias wiggle circuit that actually looked was a fender princeton reverb oscillator.
What I've heard it should be very good sounding oscillator.
Is it really that simple add on to the rocket circuit?

Also I was thinking that I should use the whole 12ax7 wired in parallel as the first stage of the rocket channel. Someone must have tried that here so opinions of that are also welcome.

Then I could also use whole tube for the trem oscillator. Any
Ideas for the oscillator or should I just go with bias wiggle circuit?

And whichis the proper or best or smartest way to combine the channels?
Feed on channel to the each input of the P.I or use mixing resistors and feed both channels at the same P.I input?

-T

[Zippy]

And whichis the proper or best or smartest way to combine the channels?
Feed on channel to the each input of the P.I or use mixing resistors and feed both channels at the same P.I input?

If the two channels are out of phase, use opposite sides of the PI. If in phase, mix.

[Dingleberry]

And whichis the proper or best or smartest way to combine the channels?
Feed on channel to the each input of the P.I or use mixing resistors and feed both channels at the same P.I input?

If the two channels are out of phase, use opposite sides of the PI. If in phase, mix.

Well it looks to me that the channels are opposite phased.
If I understood the schematics correctly the Rocket preamp is in phase with the incoming signal.
And the RT66 preamp is out of phase with the incoming signal. Just one gain stage and signal taken from the plate.

I might then be able hook up the channels using both P.I. inputs.
Someone correct me if my conclusion seems to be wrong.

-T

[Darkbluemurder]

Well it looks to me that the channels are opposite phased.
If I understood the schematics correctly the Rocket preamp is in phase with the incoming signal.
And the RT66 preamp is out of phase with the incoming signal. Just one gain stage and signal taken from the plate.

I might then be able hook up the channels using both P.I. inputs.
Someone correct me if my conclusion seems to be wrong.

-T

All correct. It's the same as in the Matchless DC-30.

Cheers Stephan

[Dingleberry]

Thank you Stephan, or shoud I say Ein herzliches Dankeschön!
I should have remembered that DC30 it's actually an amp with the same basic topology that I'm planning to do. Took a closer look at the Matchless DC30 schematic and found out that it will be helpful on the way.
My amp is only on paper right now, this time I try to plan it good. I just scored a good PT for that project. It's from Russian Rigonda Bolshoi integrated stereo radio/record player/amp that had two 2xEL84 power amp sections. I also got the both OTs and chokes and the amp boards and chassis i.e basically the whole stripped down amp for 50€. Not bad.
Starting to have all the parts on hand. Gonna use those Rigonda OTs for some 2xEL84 or 2x6V6 amps sometimes in the future.
But first back to the drawing board.
I'll let you know how my project is making progress.

-T