Low wattage Tremolo TMB reverb

[Bieworm]

Hey Josh... I would like to build a low wattage 3-5 watts tremolo TMB. Maybe ECL80 power tubes. Any ideas to pull this off?

[JMPGuitars]

Hey Josh... I would like to build a low wattage 3-5 watts tremolo TMB. Maybe ECL80 power tubes. Any ideas to pull this off?

Yeah, convert the power amp section and adjust the LTP to suit.

Thanks,
Josh

[Bieworm]

Jack, is the ECL80 a good way to go? Is the 125A a useable OT for that application? Any opinions? Jukeboxrevival sells these dirt cheap...
https://www.jukebox-revival.eu/catalogs ... t/?q=Ecl80

[JMPGuitars]

I don't really have an opinion of my own on the ECL80, I've never tried them. But from what I read of other opinions on the interwebs, it's not a great tube for guitar amps. Not great for getting good distortion, and there are stability issues people think an NFB helps with, which would obviously be a big no no for the TTMBR. I also get the impression it wouldn't give you the dirt you want either.

Thanks,
Josh

[Bieworm]

I don't really have an opinion of my own on the ECL80, I've never tried them. But from what I read of other opinions on the interwebs, it's not a great tube for guitar amps. Not great for getting good distortion, and there are stability issues people think an NFB helps with, which would obviously be a big no no for the TTMBR. I also get the impression it wouldn't give you the dirt you want either.

Thanks,
Josh

You're probably right. The moreI read about them, the less desireable they become.
VVR...that's the way to go me guesses

[JMPGuitars]

You're probably right. The moreI read about them, the less desireable they become.
VVR...that's the way to go me guesses

There's certainly other options out there. I've also toyed with the idea of doing an SE EL84 version, but that eliminates the PI, which obviously changes the sound of the amp a bit. I've also been curious about 6K6 or EL91, but I haven't bothered to look for or listen to any amps with them yet. Another option that might sound good, is to use two 12AU7s. Each one can be wired in parallel.

[Bieworm]

You're probably right. The moreI read about them, the less desireable they become.
VVR...that's the way to go me guesses

There's certainly other options out there. I've also toyed with the idea of doing an SE EL84 version, but that eliminates the PI, which obviously changes the sound of the amp a bit. I've also been curious about 6K6 or EL91, but I haven't bothered to look for or listen to any amps with them yet. Another option that might sound good, is to use two 12AU7s. Each one can be wired in parallel.

Now you mention it.. those 12AU7 tubes sound very good IMHO. It's just getting the PI to match the tremolo TMB. If I parallel them I need a 10k OT primary, right? That 125A has multiple taps.. so that's a good option..

[Bieworm]

Crap.. I should have not opted the VVR.. now he wants that. Best from both worlds...18 watt and less on tap. I Hope the VVR is gonna work out on the tremolo TMB reverb.. surely just scale down the PI and power amp to ensure tremolo to operate well?

[JMPGuitars]

Crap.. I should have not opted the VVR.. now he wants that. Best from both worlds...18 watt and less on tap. I Hope the VVR is gonna work out on the tremolo TMB reverb.. surely just scale down the PI and power amp to ensure tremolo to operate well?

I'm not a VVR guy, I can't offer any help with that. I'm sure somebody else can chime in. I would also be concerned with the trem. They should just get a standard TTMBR and use a good attenuator.

[Bieworm]

Crap.. I should have not opted the VVR.. now he wants that. Best from both worlds...18 watt and less on tap. I Hope the VVR is gonna work out on the tremolo TMB reverb.. surely just scale down the PI and power amp to ensure tremolo to operate well?

I'm not a VVR guy, I can't offer any help with that. I'm sure somebody else can chime in. I would also be concerned with the trem. They should just get a standard TTMBR and use a good attenuator.

I know...

[Daviedawg]

Yes you are right. The VVR will have to be PI and PA only as the tremolo will not work on lower voltage to its half of the preamp valve. Even small voltage changes can stop it starting up.

Dd

[Bieworm]

I thought so.. but I have been looking up amp schematics with VVR. I stumbled upon the 18W TBM SIII VVR and took that with a bit of tweaking into Josh's Tramolo TMB Reverb.
This is what I came up with... worth a shot? No offence Josh, but manipulating your schematic was the easiest way for me to clarify what I'm thinking of. Not meaning to hijack your work...

18 watt tremolo TMB reverb VVR mod.png

[Bieworm]

Tube Town sells a VVR kit. They appear to put it on the power tube screens. Is that effective compared to the usual way it's done?
https://www.tube-town.net/cms/?DIY/Amp- ... Control-EN

[Bieworm]

I have another idea.. suppose I use the primarywindings.uk 20W PTX. It has a HT secondary with an extra tap. 190V and 275V. I could look into making that switchable.. 3 way: 0-190 / 0-275 and 190-275
Suppose I can do the switching simultaneously with the cathode resistor.. wouldn't that he something to look into further? Ampmaker advertises the TX for those applications...

[geoff 1965]

That VoCo on the screen voltage looks interesting,have’nt seen any feedback though from anyone who has used it.