Low wattage Tremolo TMB reverb

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Bieworm
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Low wattage Tremolo TMB reverb

Post by 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?
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Re: Low wattage Tremolo TMB reverb

Post by JMPGuitars »

Bieworm wrote:
Sat 06/26/21 12:43 pm
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
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Re: Low wattage Tremolo TMB reverb

Post by 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
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Re: Low wattage Tremolo TMB reverb

Post by 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.

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Josh
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Re: Low wattage Tremolo TMB reverb

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JMPGuitars wrote:
Sun 06/27/21 6:52 am
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
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Re: Low wattage Tremolo TMB reverb

Post by JMPGuitars »

Bieworm wrote:
Sun 06/27/21 7:16 am
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.
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Re: Low wattage Tremolo TMB reverb

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JMPGuitars wrote:
Sun 06/27/21 7:45 am
Bieworm wrote:
Sun 06/27/21 7:16 am
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..
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Re: Low wattage Tremolo TMB reverb

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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?
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Re: Low wattage Tremolo TMB reverb

Post by JMPGuitars »

Bieworm wrote:
Sun 06/27/21 10:54 am
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. ;)
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Re: Low wattage Tremolo TMB reverb

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JMPGuitars wrote:
Sun 06/27/21 11:55 am
Bieworm wrote:
Sun 06/27/21 10:54 am
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...
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Re: Low wattage Tremolo TMB reverb

Post by 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.

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Re: Low wattage Tremolo TMB reverb

Post by 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
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Re: Low wattage Tremolo TMB reverb

Post by 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
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Re: Low wattage Tremolo TMB reverb

Post by 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...
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Re: Low wattage Tremolo TMB reverb

Post by geoff 1965 »

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