Wiring in a POT & footswitch after pre-amp, before poweramp

[swill777]

Guys, how difficult would this be to do?

Pre-Amp output, to some type of POT (mounted and screwed in the back of the amp), which runs to a off/on footswitch, then to the poweramp.
This way you can hit the footswitch, and attentuate (lower) the volume slightly, on the pre-amp side.
I HATE HATE HATE the effects loop on my 2-ch racktifier... This would let me play with the POT engaged for say a 10% volume drop, then when I hit the footpedal, I could get full bypassed volume.
It doesn't sound difficult unless I am missing something?
Any ideas on what kind (resistance) and taper pot I would need to use.
Any other thoughts?

 

[MusicManJP6]

This would be pretty much like a solo function found on other boogies correct?

 

[mikey383]

What would this be accomplishing that switching the FX loop in and out wouldn't do?

How would you footswitch the pot? By using the cable to the footswitch to bypass it, as in the cable will be part of the signal path? To do it reasonably, you would need to add a relay in the chassis somewhere. You're also looking at dissecting the PCB somewhere along the line.

I would say that adding another pot in series with the Master knob would be much better. The Master would control the overall volume, and the added pot would be able to lower the volume somewhat. You'll still need a relay, and you'll need to pick up a power source somewhere.

 

[MrMarkIII]

Guys, how difficult would this be to do?

Pre-Amp output, to some type of POT (mounted and screwed in the back of the amp), which runs to a off/on footswitch, then to the poweramp.
This way you can hit the footswitch, and attentuate (lower) the volume slightly, on the pre-amp side.
I HATE HATE HATE the effects loop on my 2-ch racktifier... This would let me play with the POT engaged for say a 10% volume drop, then when I hit the footpedal, I could get full bypassed volume.
It doesn't sound difficult unless I am missing something?
Any ideas on what kind (resistance) and taper pot I would need to use.
Any other thoughts?

What you describe is exactly what the Solo control does.
Advice: Find clue. Buy it. :lol:

 

[swill777]

I guess I forgot to mention this is a 94ish rectifier (rackmount) without a solo control, I figured it was pretty obvious that I didn't have one since I was trying to figure out how to do this. Apparently not so to some people...
Anyway, the master is in the poweramp section, correct? Controlling the overall volume?
So what type of relay do I need to use?
I guess the circuit flow would be like this?

Wire to Master --> Relay
Relay Path A (closed) --> Master POT
Relay Path B (open) --> New Pot --> Master POT

Where do you guys suggest I can tap power from specifically?

 

[mikey383]

I guess I forgot to mention this is a 94ish rectifier (rackmount) without a solo control, I figured it was pretty obvious that I didn't have one since I was trying to figure out how to do this. Apparently not so to some people...
Anyway, the master is in the poweramp section, correct? Controlling the overall volume?
So what type of relay do I need to use?
I guess the circuit flow would be like this?

Wire to Master --> Relay
Relay Path A (closed) --> Master POT
Relay Path B (open) --> New Pot --> Master POT

Where do you guys suggest I can tap power from specifically?

You'll need a DPDT relay with a coil that's the same voltage as the heater circuit...6.3VAC, 5VAC, and tap into the heater circuit. The hot wire will go right to one side of the coil contact, one wire to the footswitch will go to the other coil contact, the other footswitch wire to ground. Then you'll piggyback a wire from the wiper of the existing MV to the new pot's wiper. Lift the other wire off the MV and go to the common contact of the relay. Install another wire from the NC contact to where you lifted the wire from on the MV. Then put a wire from the NO contact to the other pot.

Hopefully this helps.

 

[swill777]

I think I get ur drawing and what you are saying... as for the type of POT, I guess just look at what the MV one is and get the same thing? If it's not too much trouble, would you mind posting a link to a radioshack (or somewhere else), to the relay part that would work, and/or the POT too? I would greatly appreciate it!

 

[mikey383]

http://www.mouser.com/Search/Refine.aspx?N=254130+4294643286+4294640789&Keyword=relay&FS=True


There's the relay. Either the first or the second one would work. As for the pot, you'll probably need to get the numbers off the MV pot and call Mesa to get one exactly like it.

FWIW, I don't recommend doing this. There are other ways to get a volume increase without modifying the amp. You'll decrease the value by doing this mod.

Personally, I would put an EQ pedal with a gain boost in front of the amp before doing this.

 

[swill777]

The problem is that I have EMG pickups, they hit the front of the amp so hard, that I don't even get any volume increase by using a TS type pedal at all. Granted, I can get a more saturated tone for sure.
So you are saying run the guitar into a EQ pedal with the volume control down a bit??? So when I stomp on the pedal (and turn it on) the volume will be slightly lower? So when the EQ pedal is off, that would be my "cut-through" lead volume?

 

[mikey383]

Yes, I think that would work. Or you could set it up so that you get a boost by switching it on rather than off. I'm not exactly sure how to set it up, as I use a rackmount processor for my volume boost on my 2 channel.

There's ways around it. Modding would be the last thing I would do in this case. Especially when it comes to messing around with anything internally.

It's not really so much about volume as it is cutting power. Sometimes changing the EQ will let you cut through better and appear louder.

 

[swill777]

You probably run your rackmount processor in your efx loop though, right? I have a Rocktron Pro-Q, and if I wire my guitar into it, then from it to the input jack.. I get a nasty kind of "ungrounded" humming-type sound. When I run it in my efx loop, it doesn't hum at all, so I know its not the unit or cables...

Wouldn't throwing a EQ pedal in-line add some "processing type" qualities to the sound? Are these eq pedal's they make now digital based? I definitely want to stay away from that. I don't use my efx loop because I can definitely hear it sucking my tone.

 

[swill777]

So this is what I have... check it.

Guitar with EMG active pickups... say switched to EMG-81 in bridge
to Bad Monkey pedal set as following:

Level almost all the way up,
Gain almost all the way down..

Then to 2-ch 94'ish dual rec.
Master set to crankin level
gain at 12-2 o'clock.

Ok, I love that tone.
So now, I just want to make that specific tone a little, like 10% louder.
Are u saying I can patch the EQ pedal in after the bad monkey to get that slight bump??

Oh yeah, I'm using Channel 1 cloned to "Red"

 

[mikey383]

Ok, since you're using the orange channel cloned to red, why not just use the red channel with a higher volume for the boost?

I know, they sound different. The orange cloned to red has more low end and low mids. I too, think it sounds better but only when it's being used alone and not with a band.

But honestly, if you're boosting for solos, you won't need that low end. In fact, you'll probably want less of it.

Just trying to give some ideas.

 

[swill777]

It seems like its practically becoming my only option, LOL.
Yeah, I used it cloned because like you said, it just sounds better.
Every time I try to use the red channel for leads, even with the bad monkey, or TS pedal in front of it, it sounds thin and ******. There is definitely something VERY different about that channel.
Anyways, appreciate the help and tips. Imma have to figure something out I guess.

 

[mikey383]

Well, you could give the mod a shot.

I'd just hate to mod a racktifier though.