Modded Tremolux

[johnnyreece]

So, I've been thinking for a while about building a 5E9-A Tremolux. However, I had a 5E3 for a while, and, while I liked it, it was pretty one-note. With the Tremolux having mostly the same front end, I was afraid of having that again, but with tremolo. I explored some different mods, and found some Tweedle Dee mods, as well as a cascading gain stage mod (among some other things) from Rob Robinette's site. In my finest Microsoft Paint work, I've cobbled a schematic together. My main questions on this will be, will the normal channel retain enough of the tweed sound? Will the lead/cascading channel be useful and significantly different? I appreciate any thoughts you all might have, and I'm very open to suggestions!

Edit: Added most up-to-date layout to top post. Will update schematic after it's built.
Edit 4-22-24: Most up-to-date layout and schematic substituted in top post.
Edit 5-6-24: Files updated to as-built versions.

[didit]

Hello —

I encourage this line of reasoning. Some long while back I built a Mission 5E3 kit, and quickly realized it was one thing only, and not my thing particularly. After research and some careful listening settled on modifications aligned with the 5E9a, however without the tremolo oscillator. It has a range of tones and dynamics that fulfills imaginations of an ideal Tweed. That kit gave robust transformers capable of swapping 6L6 and GZ34 for headroom. With 6V6 and 5Y3 it does the raw early warm break up. With GZ34 and 6V6 the tone palette is different again, similar but a bit edgy.

It did have adjustable cathode bias to make these swaps easy. I reluctantly sold it and to make it bulletproof fixed the bias resistance, which made less tweaking but minimized risk of losing a pair of 6V6 to redplate. The current owner runs only 6L6 and regularly comments on how pleasing the amp is across a range of guitars and styles of play.

Best .. Ian

[Colossal]

Johnny,

I have a big box 5E9 cab, chassis and PT waiting on deck for a Tremolux build as well. I just finished a 5E3 style build with some mods. I don't like the interactive controls of the 5E3 so did away with that. I have just a single channel voiced closer to the bright channel and used the extra Volume as a master in front of the phase inverter. That turned out to be very effective and useful. I used a choke in series with the 4k7 screen resistor. I changed the cathodyne a bit and a few coupling caps as well. It came out great and I have been playing it with a band. The voltages are lower, but I can pop in a GZ34 for standard 5E3 voltages. But I've been playing it with an NOS 5Y3GT and prefer that, so far.

The Tremolux will have a lower B+ Bandmaster PT. Still deciding on an OT as I may want to do something to allow for 5881s and/or 6L6s.

[johnnyreece]

Thanks for the encouragement, fellas. I guess at this point, I'll try to put together a proper schematic and layout. I'm also pretty sure I'm going to go for a 6SL7 for my tremolo tube. Any modifications needed for that, or should I be okay with stock values?

[didit]

I'm also pretty sure I'm going to go for a 6SL7 for my tremolo tube.

Any reasons for heading off the page?

..

[johnnyreece]

The chassis I have (Weber 6MX) has an octal socket there. I could always just get an adapter, I suppose. If it doesn’t end up strong enough, I just might.

[sluckey]

I have a 6SL7 tremolo circuit in my slightly modified Ampeg J12. Works fine.

http://sluckeyamps.com/RCA/Ampeg_J12B.pdf

[johnnyreece]

I have a 6SL7 tremolo circuit in my slightly modified Ampeg J12. Works fine.

http://sluckeyamps.com/RCA/Ampeg_J12B.pdf

I was secretly hoping you would chime in on this. You seem to be the expert on all things tremolo. I'm assuming I'll do the yellow LED cathode mod. I may even incorporate your speed switch, as it's pretty darn handy. Any other suggestions? I'm guessing this will be a "try it and see what works" amp, so I'll not get too hung up on minutiae yet. The plan is to get a layout together based on the current schematic, along with any planned mods. Then, create a final "as built" schematic/layout when it's all done.

[sluckey]

I'm certainly no tremolo expert but I do like to experiment a bit. I normally use a red LED but this amp is built in an old radio cabinet. The LED is behind the glass dial plate. Yellow matches the looks of the cab better than red. But red or yellow work equally well.

http://sluckeyamps.com/RCA/RCA.htm

[didit]

Hmmm --

All makes total sense now. I've an original 1960 Jet, and that tremolo is just fine. Glad to see you had the essential details well captured Steve.

What to do with that spare triode though?

Best .. Ian

[sluckey]

What to do with that spare triode though?

What spare triode?

[didit]

What to do with that spare triode though?

What spare triode?

Unless I misread this thread the plan is to put a 6SL7 into an extra octal socket spot. That’s two triodes. The Jet trem circuit will use but one, leaving a spare — no? Or did I lose the thread somehow?

..

[sluckey]

Unless I misread this thread the plan is to put a 6SL7 into an extra octal socket spot. That’s two triodes. The Jet trem circuit will use but one, leaving a spare — no? Or did I lose the thread somehow?

Sorry to mislead. I never intended to put the J12 circuit in the Tremolux. I was merely showing johnny that a 6SL7 could be successfully used as a trem oscillator. Just substitute the 6SL7 in place of the 12AX7 in the Tremolux circuit. Hopefully without having to change any circuit components.

[didit]

Unless I misread this thread the plan is to put a 6SL7 into an extra octal socket spot. That’s two triodes. The Jet trem circuit will use but one, leaving a spare — no? Or did I lose the thread somehow?

Sorry to mislead. I never intended to put the J12 circuit in the Tremolux. I was merely showing johnny that a 6SL7 could be successfully used as a trem oscillator. Just substitute the 6SL7 in place of the 12AX7 in the Tremolux circuit. Hopefully without having to change any circuit components.

Ah but your single triode Jet trem might’ve been the best answer.

..

[sluckey]

Ah but your single triode Jet trem might’ve been the best answer.

Maybe. But the Tremolux paraphase inverter might not get along with the J12 trem. I don't know. Looks like the trem would also couple through that 6800Ω to the lower PI grid. I have no idea what might happen with that. Could be a new discovery. Could also be a heartbreaker!