Swapping Drive/Level Control With Timmer...Better?...Worse?

[Smitty]

Seems like the Volume control feeding CL2 (is that the nomenclature used here?) dictates the level of drive at both CL2 and OD1 on the current setup. Unless the top of your amp comes off like a convertible top (mine actually does) so you can play with the trimmer.

I'm thinking about swapping the circuit location of the Level control and the trimmer on my 183/102 so that I can more easily dial in overdrive at OD1 independent of hoe I'm driving CL2. I only like a little bit of overdrive at OD1 and then just a little bit more on OD2 which I could dial in with the trimmer once I have OD1 set and then forget about it.

So Level on first overdrive and trimmer on second overdrive stage. That way I can have both OD stages lightly in overdrive no matter where I have the Volume set.

Anyone ever tried this? Have I wandered off the ranch?

[alvarezh]

Hi Smitty, what some people do (me included) is to replace the OD input trimmer with a pot mounted on the back, now we have all controls readily available. I use a knurled 16mm mini pot without a knob.

Hope this helps.

[marcos]

Hi Smitty,
I had this mod in my amp (79 ODS) at one time, it was my amp tech´s idea who thought it was "better" to have the level control in this place ( OD entrance).
As far as I remember higher OD settings yielded more compression, making the ODS sound more like a Boogie. Later on I changed the amp backed to original specs. Personally, I would recommend replacing the OD trimmer
with a pot, as HAD did on #121 and the "Phoenix" preamp IIRC.
This way you have all the options, however , dialing in can be tricky. I had the pleasure to try #121 once, and I remember that it was real easy to achieve unusable (to my ears) tones with the settings of the "Trigger" and "Level" pots (using HAD terminology here).
Hope this helps a bit

Marcos

[bluesfendermanblues]

..............
So Level on first overdrive and trimmer on second overdrive stage..........

That's the way its done in Mesa Boogies MK II - IV.

Try it out to see if you like it better!

[Smitty]

alvarezh,

Oh yeah, baby! Excellent idea. I love adding knobs!!

marcos,

I think your probably right that higher OD setting could sound more compressed. Given that I'm looking for lower OD settings your comments are encouraging.

bluesfendermanblues,

Thanks for the schematics.

Smitty