Wiring help for 9v Pre-Amp

[robin]

To all the wiring gurus out there (Weirdy, I’m looking at you) I could do with some advice please.

I am still researching my next build but (if I go ahead) it will include a pre-amp that I already have laying around that has volume, eq, etc as part of a unit that is meant for external mounting on an acoustic guitar. My plan is to locate this pre-amp INSIDE the body of the guitar thus making access to the volume knob rather problematic.


I was wondering if I could set the volume on the pre-amp to max and then insert another pot on the wiring that goes from the pre-amp unit to the output jack thus giving me an external volume knob. Would this second pot interfere/degrade the signal and if not would I need a special pot for this or would one of the run of the mill 250/500k pots do the job. Once the guitar is complete I could experiment with pots to see which gives me the sound I am after.

As I am a complete numpty when it comes to wiring any help would be appreciated.

Cheers
rob

[wokkaboy]

good stuff Westie07, is this an acoustic guitar or bass ?

better wait for the guru to respond. I'd guess a standard A type pot should be fine for the volume and shouldn't affect the signal.

[WeirdBits]

Do you have any details for the pre-amp, make/model, images etc? I take it you want to keep the pre-amp intact, not disassembled/modified etc?

[robin]

Hey there Warren. Acoustic? I wish.

It will be another solid body pine scratchie. I have not made any decisions as yet just thowing up a lot of ideas for now.

Researching the build is part of the fun. I need to boot The Black Dog out, so I will probably take some time with this one.

Hopefully I will make a decision soon and get started.

[wokkaboy]

Hey Westie, I didn't read your 1st post correctly, I see the unit is off an acoustic !!

sounds good bro

wiring guru chimed in needs more info

who the hell is Warren ? bwhahahah

[robin]

who the hell is Warren ? bwhahahah

I'm still trying to figure out who Westie is.

[robin]

Thanks Scott for your help.

Its a Fishman, but I have no idea of model or specs. I know it was originally for a piezo pickup.

As long as it's not too technical, pulling it apart is no problem. I have already taken the back off as I will have to remotely locate the battery box as it is too big to fit in a regular size solid body electric. I'll post some pics tomorrow.

Thanks again for any help.

[robin]

D'oh. Double post

[WeirdBits]

You're planning on embedding this in the guitar to use with a piezo pickup, right, rather than trying to use it to amplify a standard magnetic pup? If it is the latter then it probably won't work well due to the low impedance of magnetic pups vs the high impedance of piezos.

[robin]

You're planning on embedding this in the guitar to use with a piezo pickup, right, rather than trying to use it to amplify a standard magnetic pup? If it is the latter then it probably won't work well due to the low impedance of magnetic pups vs the high impedance of piezos.

Thanks for the info Scott.

Yes I was planning to embed the pre-amp and not use any of the controls on the unit, and just have an external volume pot. I was undecided as to what pickups to use, but it appears that magnetics are out of the question. So if I want to use this pre-amp it will have to be with a piezo. Hmmm.

I need to rethink a few things now. If I did use this pre-amp with the piezo do you think that a second volume pot would work OK?

And one more question, there are 3 wires going from the pre-amp unit to the output jack. What do you reckon, stereo or something else going on?

Cheers mate
rob