Getting rid of a channel - Vibroverb

[jhawk]

Hey guys, I'm just wondering if my reasoning is correct here. In the picture below, I've marked in red where I'd "cut" the wires to make the vibroverb into a single channel amp (the bright channel). Is this right?
[IMG1763]http://i.imgur.com/OCMYPOf.png[/img]
I also plan to take the freed up power that would have been used to heat the tube from the normal channel and use it for a relay to control a volume boost, and maybe a second pilot that shows when it's on. Any foreseeable problems there?
(And don't worry, I'm not modding a rare vintage amp--this is for a build )

[martin manning]

You'll want to put a 470k from the junction if the 1M resistor and the PI input cap to ground. That will take the place of the 220k mixing resistor and the 220k plate load of the last stage of the normal channel. Also, you may want to increase the value of the 10k between power supply nodes C and D to ~15k to restore the plate voltages.

Getting relay power from the filament circuit might be tricky. Have you thought that through?

[Blackburn]

I did it with great success and just cut the verb. I love that amp. Very nice and sweet clean tones and a nice hypnotic trem. I used 100k plate resistors on V1 and used the 500pf PI entrance cap as the coupler from the second stage. Very funky treble control. I wired it up stock like the schem and it's pretty cool.

[gui_tarzan]

I want to do the opposite (removing the trem circuit instead of the reverb) because I never use it but I'm not sure how to terminate it..

[jhawk]

Getting relay power from the filament circuit might be tricky. Have you thought that through?

Wrong voltages? Do relays need clean power?--do they need run through some filter capacitors? I'm pretty new to all this circuitry stuff and trying to figure it all out!

[jhawk]

So this is what I should do, martin?
[IMG1763]http://i.imgur.com/Fk7Roo5.png[/img]

[martin manning]

Yes, but I'd take the 470k resistor to ground, and you should increase the 820R resistor at "A" to 1k5.

For relay power I'd do a separate supply using a small auxiliary transformer.

[jhawk]

This?
[IMG1763]http://i.imgur.com/uinMcBk.png[/img]

[martin manning]

The 470k is still not right. Delete the line with "+195V" next to it.

[wyatt]

I want to do the opposite (removing the trem circuit instead of the reverb) because I never use it but I'm not sure how to terminate it..

The trem is "wiggles" the power tube bias. You scrap the tremolo circuit and leave a traditional adjustable fixed-bias circuit in its place.

[jhawk]

Thanks for your patience! I'll clean up this schematic then...maybe I'll make it on inkscape or something. If anyone wants me to re-post a cleaned up version let me know.
[IMG1763]http://i.imgur.com/aPlEasv.png[/img]