Idea for a Studio .22 + mod.

[thingthatgoes]

Hi all.
Straight to the point version is below.
I've had a DC3 combo that I've had forever and love. It's the only main amp I've ever owned for 20+ years. I recently got my hands on a Studio .22 + w/out EQ. I love the lead distortion when it's maxed out but I want to do the opposite of every mod I've seen and instead of lowering the lead gain or enhancing the rhythm volume or gain I want to give myself a way to LOWER the gain on the rhythm channel without having to sacrifice any gain on the lead. I mean, I love how great the clean sounds but when I have the pre volume up to where I want the lead to really kill I find that the clean is just too dirty. Which is great for other things too but not what I mostly want.
Any insight or advice would be really appreciated.
After looking through the print and scouring the internet I came up with this.



*********** to the point**********
For a separate rhythm channel gain control I want to put a pot (or resistor) across the LDR1 contacts. I'm sure this wouldn't have any effect on the lead sound as it would get shunted by the LDR1 while in the lead function (no issues here, right?). And when it's on rhythm, some of the signal would flow through the grids of V1A/B and the 470k (R291) resistor to ground. Not much different than the volume knob of the guitar. And the V1 signal should *not* get amplified or go anywhere because of LDR2 keeping the V1 output open from the rest of the circuit AND the 470k R292 shunts and stray signal to ground. ...hopefully.
What do you guys think? Before I go bench testing these ideas I'd like to know as much as I could expect as possible. This seems super easy to get done as well so I'd love for it to work for others to try.

 

[CoG]

Uhm... I'll let someone with better kungfu than me check your idea there, but just before you put it on the bench, have you tried putting a 5751 in V1? I'm willing to bet you won't notice a difference on your lead drive but it should give you some more clean headroom to play with.

 

[thingthatgoes]

I considered that but I doubt that it wouldn't change the gain in the lead channel but it's worth a try. Thanks.
I'm thinking that worst case scenario with my mod I'll have V1 bleeding into the clean function. Something similar happened when my DC3 had a bad vactrol keeping closed on the input. It's a different animal though so I'm a bit hopeful.

 

[woodbutcher65]

If you want to mod a .22 then I highly suggest you start with COOLING mods.

I had one that had overheated so badly, it unsoldered itself! Not even kidding. The PC board was changing color from heat discoloration.

I removed the garbage internal reverb tank, converted it to run a full size tank down in the bottom of the cabinet like any Mark series amp, and used the freed up space with its vent holes in the back panel to install 2" wafer fans and installed a small power supply to run them. The amp ran a LOT cooler then.

The 2" wafer fans had a mounting hole pattern that lined up perfectly with the cooling slots in the back panel, so it was a "no butchery required" mod. Just get some long screws and I'd recommend some rubber washers, too. If you pick the right fans they're basically silent but if you want REAL silence for recording purposes, you could always install a fan cutout switch. In that case you're probably running the amp in a cool, air conditioned studio anyway.

 

[lenniepickit]

I considered that but I doubt that it wouldn't change the gain in the lead channel but it's worth a try. Thanks.
I'm thinking that worst case scenario with my mod I'll have V1 bleeding into the clean function. Something similar happened when my DC3 had a bad vactrol keeping closed on the input. It's a different animal though so I'm a bit hopeful.

I've been playing around with this a lot and V1 ONLY effects the lead channel gain. I wanted to check that and discovered that when you're on the clean channel you can literally pull v1 out with out affecting the gain structure of it. Conversely if you pull V2 while on the lead channel it's gone.

 

[thingthatgoes]

That's the thing, if I go across the LDR1 contacts I'll be having V1 engaged. LDR1 (being open) is what's keeping V1 from being engaged. So I'd be introducing a pot in series with 470k to ground through the grids of V1.
Anyway, haven't had time to try it yet.