RK Dual Showman Mod the Gain on Chan 2

[Gavman]

The goal is to leave as is the sky-high headroom on channel 1, while modifying channel 2 completely. Seeking ideas for a mod of chan 2 that would approach Marshall gain (only half joking) in a lead channel. Really any mod to improve gain in chan 2, toward MB, or M1987. Is it possible to create a separate preamp and bypass much of the pcb? It is such a beast to only be able to use the clean channel, as beautiful as it sings. I'm not ambitious enough to wire in reverb.

Threads or forums talking about substantial mods to RK circuits have been difficult to find. Have many/any removed the pcb entirely and hardwired a 60's Showman AB763?

Thank you all so much, I enjoy the technical posts here, and appreciate the amount of wisdom from experience.

[pdf64]

... RK circuits have been difficult to find. Have many/any removed the pcb entirely and hardwired a 60's Showman AB763?...

I can't make sense of your post - a Showman AB763 doesn't have a printed circuit board, they are handwired
What's an RK circuit - Mesa Road KIng? If so, where does the Showman come in?

[Helmholtz]

RK = Red Knob?

[Gavman]

Yes, Red Knob Dual Showman.

Apologies for the ambiguity above. I'm looking for specific or conceptual ways people have modded or just thought about what one could do to the lead channel

[pdf64]

Try making the values of C19 (need to pull the treble boost) / R44 5 to 20 times bigger http://ampwares.com/schematics/Red_K...al_Showman.pdf
C112, the 'C' node HT cap will need to be in good condition, may need its value increasing.

[Helmholtz]

My suggestion woud be to use only the clean channel with a Zendrive (buy or build). I guess that's what Robben Ford did when he used the RK Twins.
I love a Zendrive with my BF Fenders.

[vintagekiki]

... ...

Why slaughter an excellent amp.
Play it like Hedrix: all controls put at 10 and you will have desired sound.
Or sell it and buy an amp that will be tailored to you (MB mk1 or M1987)
If you decide to create a separate preamp, connect it to J203 (power amp input).

[g1]

This is the same chassis as the red knob The Twin. It may help to say what you don't like about ch.2. From what I recall the dirty channel can dial in quite a lot of overdrive, more than older marshalls.

[vintagekiki]

TheTwin om.pdf

This is the same chassis as the red knob The Twin. It may help to say what you don't like about ch.2. From what I recall the dirty channel can dial in quite a lot of overdrive, more than older marshalls.

The red knob The Twin doesn't set as the amps, which our ears been accustomed to for years. In order to get the most out of it, similar to MB, you should for first use the factory sample settings (Owners Manual page 8).

Tone is a matter of personal taste.
The OD channel is thin in bass, and the OD without bass is like bones without meat.
More bass in OD channel is obtained by change C18 (.0068) to the value .01 - .022, and possibly by change C101 (.0022) to the value .01 - .022

Better sonic is obtained by excluding physiological correction of volume R40 (1k)
Remember the presence control has a pull switch, and work as boost or notch,