Plate-driven tonestack in Rocket?

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Gaz
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Plate-driven tonestack in Rocket?

Post by Gaz »

Anyone skipped the CF, and driven the tonestack from the plate? I'm looking to get a bit more range from the tone controls. I love the amp, but I think the tone controls are even more useless than a Plexi, especially the bass control. I know any EQ won't be much good once the power tubes get cooking, but still... Anyone feel the same?
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rp
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Re: Plate-driven tonestack in Rocket?

Post by rp »

Gaz wrote:Anyone skipped the CF, and driven the tonestack from the plate? I'm looking to get a bit more range from the tone controls. I love the amp, but I think the tone controls are even more useless than a Plexi, especially the bass control. I know any EQ won't be much good once the power tubes get cooking, but still... Anyone feel the same?
Matchless Spitfire style and drop the T&B to a Tone? Or even skip the tone? I have this schematic from somewhere:

On my Lighting clone (pretty much a Rocket) I added a mid pot, 25K?, and I made the resistor a value that centered the pot at stock. Really changes things particularly in your interfacing with the amp in a way some who hate the Vox interactive T & B effect might prefer. I could take or leave the interactive thing but I found more choice more frustrating and it made my Matchless more Fenderish and put it back. Haven't finished my Rocket yet, don't recall if it has the Bass pot grounded like the Vox, think it does but you might want to try the Fender/Marshall style TMB first, but as you hate the Plexi tone controls too, you might not :?
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sliberty
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Re: Plate-driven tonestack in Rocket?

Post by sliberty »

I am surprised to hear you saying that the Rocket tone stack is ineffective. Mine is VERY effective. Tons of bass and treble available to tune in as you see fit. Maybe something else is going on in your amp?
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rp
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Re: Plate-driven tonestack in Rocket?

Post by rp »

On further thought, the whole point of the top boost was to recapture the vim lost when Vox decided to replace the troublesome EF86 with a 12AX7 and also add bass and treb. So if you did what you want to do it would probably be kind of lame. Which you might then unlame by changing the 12AX7 to an EF86. But then you've got a totally different amp - but would have experienced the full circle of Vox-Matchless-Rocketness :lol:

As sliberty said, the praise for the Rocket is practically unanimous, all those Rocket fans can't be wrong? I'll find out soon enough.
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Gaz
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Re: Plate-driven tonestack in Rocket?

Post by Gaz »

Nothing wrong with the Rocket, I just think the tonestack doesn't work that well, especially the amp's turned up. This is to be expected from an amp with a CF-driven EQ and tones of post-stack overdrive. The EQ works well enough at low gain settings.

MY main gripe is with Bass control. It cuts bass okay, but little to o difference is heard when you turn the bass control past noon. I don't really want to change the curve of the EQ, so I though plate loading it may be a good idea, and then to make up gain elsewhere. I have a 220k/220K divider before the PI, and no bypass cap on the 2nd stage, so I figure there's still plenty of gain to made up for.
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rp
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Re: Plate-driven tonestack in Rocket?

Post by rp »

Gaz
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Re: Plate-driven tonestack in Rocket?

Post by Gaz »

Don't mind my funky terminal strip wiring, but this is how I've wired the stack, moving the 10K resistor to ground to avoid the 'bass on 10 scoop' thing.
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Firestorm
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Re: Plate-driven tonestack in Rocket?

Post by Firestorm »

May be the guitar. Amp tonestacks are mostly passive and can only cut frequencies. I have humbucker-equipped guitars that always have too much bottom; and single coils that are always too bright. The only guitar I have where I can really dial it in is one with active pickups.
skeezbo
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Re: Plate-driven tonestack in Rocket?

Post by skeezbo »

Kevin O'Connor has an AC30 inspired circuit in one of his books.
The tone stack is plate driven. He claims it has less stiffness than the CF.
I am not sure what stiffness is, exactly. He also seemed to prefer to not have an unused triode: he included a reverb circuit and an effects loop option as uses for the extra 12AX7. It would be interesting to hear a Rocket with a plate driven stack.
Skeezbo
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