Wiring help for 9v Pre-Amp

[robin]

Thanks for the link Brendan. I like the look of that bridge. Opens up all sorts of possibilities.

Unfortunately I have to use what I've got for this build. But maybe next time.

[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

[kimball492]

If you have the right bridge that takes a piezo mic you could then use this Robin. But may be costly

[WeirdBits]

it's a stereo socket with used to power on the system. Insert a standard mono plug and it completes the battery's negative connection by shorting the ring to the sleeve, turning the power on. You will be able to use a stereo version of our standard open guitar jacks to do the same thing, rather than having to use the endpin jack.

You could run another volume, it probably uses a 50K pot, how you connect it would depend on how the original is wired. Are you going to make the preamp's controls accessible on the back of the guitar or hidden under a cover? If possible I'd leave them accessible (along with the 2nd volume) and do a combined piezo and magnetic pickup build. If you google 'piezo preamp with magnetic pickup' and similar terms you should find a lot of layouts where people have combined their piezo circuit with a passive magnetic pup circuit etc. so you can have both in the one guitar.

[robin]

If you have the right bridge that takes a piezo mic you could then use this Robin. But may be costly

Thanks KB. I was hoping for a easy (AKA cheap) solution, but it looks like I may have to rethink things. But thanks anyway.

[robin]

You could run another volume, it probably uses a 50K pot, how you connect it would depend on how the original is wired. Are you going to make the preamp's controls accessible on the back of the guitar or hidden under a cover? If possible I'd leave them accessible (along with the 2nd volume) and do a combined piezo and magnetic pickup build. If you google 'piezo preamp with magnetic pickup' and similar terms you should find a lot of layouts where people have combined their piezo circuit with a passive magnetic pup circuit etc. so you can have both in the one guitar.

Thanks again Scott. The original plan was to max everything out on the pre-amp, "set and forget" and hide the it under a cover. I would control volume with the second volume pot and save a few presets in my fx pedal to take care of tone settings.

Thanks for your time mate, I think I need to do some more research. I think you have just saved me a massive headache.

Back to the drawing board.

Cheers
rob

[WeirdBits]

Is there a specific reason you wanted an onboard preamp to use with magnetic pickups?

If so, you can easily make your own small preamp for around $10. I'm looking at an onboard circuit now that will give 2x-10x amplification. It has 1 switch, 1 gain pot and 1 IC and you can build it on a small piece of Veroboard. Very easy to build.

[robin]

Is there a specific reason you wanted an onboard preamp to use with magnetic pickups?

If so, you can easily make your own small preamp for around $10. I'm looking at an onboard circuit now that will give 2x-10x amplification. It has 1 switch, 1 gain pot and 1 IC and you can build it on a small piece of Veroboard. Very easy to build.

No logical reason Scott. Just had it and some PBG original magnetic pickups laying around and thought, what the heck, I might as well put them to use. I really need to keep myself busy and although I could easily spend the time doing some much needed house reno's the only thing that really works for me at present is to throw my energy into guitars.

Based on what you have already told me my thinking has changed somewhat and I might use the Piezo in another guitar. As I said, more research needed.

That DIY pre-amp sounds very tempting and although a complete novice at electrocutions, I would be eager to try this for a future build.

Ta mate
rob