My kid wants a Jerry Cantrell amp...

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cstenger5
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My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

So my assignment is to find a layout for a high gain 18 watter. I'm sure it doesn't need to be quite an Uberschall or an Ecstasy, but probably something in the jcm800 range would do. Any recommendations from the crew for an 18 watt something or other like that?
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Re: My kid wants a Jerry Cantrell amp...

Post by Riffmonster »

Hi,

You could build this one here: https://www.tube-town.net/cms/userfiles ... -schem.pdf

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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

I would start with the section labeled "High Gainers" in the downloads: viewtopic.php?f=25&t=24426
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

Any thoughts on the Ceriatone TMBEF?

Looks kinda perfect to me, feature wise. I'm assuming I can take the power section from the latest stuff from Josh, and use the Ceriatone preamp?

http://www.ceriatone.com/ceriatone/wp-c ... iatone.jpg
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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

cstenger5 wrote:
Sun 10/03/21 12:02 pm
Any thoughts on the Ceriatone TMBEF?

Looks kinda perfect to me, feature wise. I'm assuming I can take the power section from the latest stuff from Josh, and use the Ceriatone preamp?

http://www.ceriatone.com/ceriatone/wp-c ... iatone.jpg
I'm not sure what you're looking for feature-wise, but there's not much going on there with that amp. That's basically like any of the 2 channel TMB amps, with an EF86 in the non-TMB channel. The tone knob is interesting, but I don't know why you would want that if you haven't specifically heard an example that you like.

If you want a 2 channel amp with an EF86, check out the EF86 Modern Classic (not a TMB amp though): viewtopic.php?f=25&t=25606

Hmm, I guess I haven't drawn one of the standard TMBs. Maybe I'll get around to that if I even find some free time. 🤣

If you want high gain, you should look at the EF86 Xtra (that's the same circuit as the head I sent you a link to). I am considering eventually releasing my Xtra TMB circuit, though I dunno if/when that will happen. That can also be made to work with the EF86, as it's similar to the EF86 Xtra, but has a TMB tone stack.

Thanks,
Josh
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

Criteria are high gain, TMB, 2 channels, and the bonus with the Ceriatone is getting to mess with an EF86 in amp that probably won't be a worry if there are some microphonics from a channel that doesn't get used a whole lot. He's never once used the low gain channel on the Mojotone18 watt I built. The EF86 channel and rotary is based on the Matchless DC30 high gain channel. I don't know how it'll sound with the 18watt Marshall power section, bit it's pretty amazing in the Matchless.
I played the Mojotone next to a JCM800, and it wasn't too far off, in terms of gain from the JCM. Much fatter and chimier though. He can get close enough to Facelift and Dirt tones with it, but not like the newer Bogner branded stuff. So we're going for higher gain than the mojo.
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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

cstenger5 wrote:
Sun 10/03/21 7:52 pm
Criteria are high gain, TMB, 2 channels, and the bonus with the Ceriatone is getting to mess with an EF86 in amp that probably won't be a worry if there are some microphonics from a channel that doesn't get used a whole lot. He's never once used the low gain channel on the Mojotone18 watt I built. The EF86 channel and rotary is based on the Matchless DC30 high gain channel. I don't know how it'll sound with the 18watt Marshall power section, bit it's pretty amazing in the Matchless.
I played the Mojotone next to a JCM800, and it wasn't too far off, in terms of gain from the JCM. Much fatter and chimier though. He can get close enough to Facelift and Dirt tones with it, but not like the newer Bogner branded stuff. So we're going for higher gain than the mojo.
I dunno if it will be high gain enough for him, but it sounds like it's pretty close otherwise. If you don't love the EF86 channel on it, try the EF86 version I designed for the EF86 Xtra. I found the distortion a lot more pleasing, and the tube was less microphonic than the common EF86 implementations.
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

I wonder if I could use that second triode in the Xtra as a cathode follower driving a tone stack, since he's definitely going to have a desire to tweak low/mid/high. Although I'm assuming I'd be forfeiting the gain from that v2b to do that. I think your xtra is an awesome concept, based on the stuff I've played with EF86s. The touch sensitivity in that channel on those DC30s is insane.

ef86 plate -> gain pot -> v2a grid -> v2a plate -> v2b grid -> v2b cathode -> tone stack.

I'm going to assume I'd need to experiment with different value components and voltages, which means I need to read up (a lot) more :)
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

Or hell, what about replacing the v1a stage and associated components with from the TMB tremolo circuit with the Xtra ef86 stage and associated components, removing the tremolo. I'm assuming it's naïve of me to assume it's just that simple, but maybe a starting point?
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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

cstenger5 wrote:
Mon 10/04/21 12:33 pm
Or hell, what about replacing the v1a stage and associated components with from the TMB tremolo circuit with the Xtra ef86 stage and associated components, removing the tremolo. I'm assuming it's naïve of me to assume it's just that simple, but maybe a starting point?
Actually, it probably is that easy, except replace all of V1, not just half. V2 is parallel to smooth out V1's gain, and drive the TMB. So with an EF86 in V1, that's pretty close to how I would do it to turn the EF86 Xtra into an EF86 Xtra TMB. There would likely be some tweaking, and you'll want to keep the "gain" pot and the resistor leading to it. At least in the beginning when you're figuring out how the gain and such works out.

Hmm, maybe I should release the Xtra TMB, and make a quick EF86 version of it. 🤔

Thanks,
Josh
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

You should, you should! :)

Thanks for the insight!
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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

cstenger5 wrote:
Mon 10/04/21 5:22 pm
You should, you should! :)

Thanks for the insight!
I'm leaning that way. ;) But I've got other things to do first...so as soon as I want to procrastinate something, it will probably happen.
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

JMPGuitars wrote:
Mon 10/04/21 4:56 pm

Actually, it probably is that easy, except replace all of V1, not just half. V2 is parallel to smooth out V1's gain, and drive the TMB. So with an EF86 in V1, that's pretty close to how I would do it to turn the EF86 Xtra into an EF86 Xtra TMB. There would likely be some tweaking, and you'll want to keep the "gain" pot and the resistor leading to it. At least in the beginning when you're figuring out how the gain and such works out.

Thanks,
Josh
So would that be: Xtra V1 -> Tremolo TMB V1b (as V2) ->Tremolo TMB V2 (as V3), -> PI etc?
If that's the case, I'd be able to use the unused triode (Tremolo TMB V1a) for a low gain channel 2, unless my assumption above is wrong, or I'm missing something else.
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

cstenger5 wrote:
Tue 10/05/21 9:17 am
JMPGuitars wrote:
Mon 10/04/21 4:56 pm

Actually, it probably is that easy, except replace all of V1, not just half. V2 is parallel to smooth out V1's gain, and drive the TMB. So with an EF86 in V1, that's pretty close to how I would do it to turn the EF86 Xtra into an EF86 Xtra TMB. There would likely be some tweaking, and you'll want to keep the "gain" pot and the resistor leading to it. At least in the beginning when you're figuring out how the gain and such works out.

Thanks,
Josh
So would that be:
Xtra V1 (EF86) -> Tremolo TMB V1b (as V2 w/tremolo function) ->Tremolo TMB V2 (as V3 w/tone stack), -> PI (as V4) etc?

If that's the case, I'd be able to use the unused triode (Tremolo TMB V1a) for a low gain channel 2, unless my assumption above is wrong, or I'm missing something else (I probably am). He won't ever use tremolo from that V1b, so that's not a needed function, but if I'm understanding right you're saying I need that for the parallel thing.

Thanks again for all this insight. It means a lot.
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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

cstenger5 wrote:
Tue 10/05/21 9:17 am
So would that be: Xtra V1 -> Tremolo TMB V1b (as V2) ->Tremolo TMB V2 (as V3), -> PI etc?
If that's the case, I'd be able to use the unused triode (Tremolo TMB V1a) for a low gain channel 2, unless my assumption above is wrong, or I'm missing something else.
No, there's nothing extra. Ha, puns. Xtra V1 is a pentode, not a dual triode (think two tubes in one). TTMB V1a is your input, and V1b is the tremolo. You're eliminating the trem, and still need an input stage, which will be your EF86 from the Xtra.

So V1 (EF86 Xtra V1) -> Trem TMB gain pot/voltage divider -> V2 from Trem TMB etc... Literally just swap out V1 sections, then FAFO.
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

GOTCHA!

I was thinking you meant that I'd have to swap out the whole Tremolo TMB V1, which i interpreted as "since there's 2 triodes in V1 of the Tremolo TMB, that means I need to swap that out with the pentode *and* half of another 12ax7 for some reason I'm still too green to understand."
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Re: My kid wants a Jerry Cantrell amp...

Post by zaphod_phil »

There's a much simpler way that doesn't require messing with a pentode (although I actually like pentodes). Just build an 18W TMB amp with the Normal channel's output, taken from the wiper of the Normal channel's volume pot, cascaded into the TMB channel's input, via a 10nF cap. That will give you some huge gain! :D I once did this same mod, known as the "one wire mod", for a customer special order, while I was working with Trinity. Maybe it should have been called the "one cap" mod instead LOL.
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

Well that sounds awesome. I've already started on the EF86 one, but if that mod is as simple as that, I could probably add it to my Mojotone TMB and give that one to him.
Then I'd get to keep this one for myself...

Oh man.

That's got to be the plan.

:D :D :D

Do you have any drawings of that, so I can't accidentally destroy it all with my alternating over confidence and total lack of confidence?
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Re: My kid wants a Jerry Cantrell amp...

Post by cstenger5 »

Would that be normal channel vol wiper -> 10uF cap -> TMB channel input tip?
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Re: My kid wants a Jerry Cantrell amp...

Post by JMPGuitars »

cstenger5 wrote:
Sat 10/09/21 9:37 am
Would that be normal channel vol wiper -> 10uF cap -> TMB channel input tip?
You want to go normal Volume wiper -> 10nF (not µF) -> tube grid input for TMB channel. V1 pin 2 in this schematic: storage/18watt_tmb_JAschematic.pdf

However, I would probably also use 10K grid stopper resistors on both halves of V1.

I suppose you could make it switchable too. Have a switch determine whether the TMB input is cascaded from the Normal channel, or comes from the TMB input instead.
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