DIY acoustic to acoustic/electric?

[methodofcontrol]

hey guys...i made (from scratch) an acoustic guitar a few months back and it plays and sounds great. what i really want is an acoustic electric so i can try it through some pedals or an amp, i was hoping to apply my soldering/electrical skills to building an onboard pre-amp for it. then i would install it so the control panel is on the upper bout. the only problem is, i haven't been able to find any info on doing this. i figured there would be something you could buy like what i'm referring to, and then you'd have your local guitar tech install it for you. i thought i'd find something like that and copy the schematic. but no luck...any ideas?
any info for me?
thanks!

[Steve Conner]

I've never seen schematics for those preamps either, though you could try googling it (Fishman is the most famous brand, afaik)

The piezos are rather prone to feedback if you plug into a guitar amp, anyway. I think you would get better results with one of those magnetic pickups that clips into the soundhole. It's basically a Strat pickup mounted on a weird-shaped clip. They say that magnetic pickups don't work with phosphor-bronze acoustic strings, but I've seen these pickups working with my own eyes, or rather ears. I think only the wrappings are phosphor bronze and the core wire is steel.

[Rob Mercure]

To echo Steve's thoughts - piezo pickups sound nothing like a true acoustic sound and are "quacky" and compressed. It's hard to get an acoustic sound - like when you play it unamplified but just louder - without using microphones of some kind. I've found over the years (have many discarded piezos and attachable mics) that a soundhole magnetic such as the Fishman Rare Earth series doesn't produce a true acoustic sound but does give you a good "large archtop hollowbody electric" sound that works great on stage without much feedback which can also be "cranked up" for a leads and such without trouble. It's all a compromise but I've come to truly hate the sound of most piezo - good for finding submarines and little else <grin..

Rob

[Steve Conner]

Rob, does this mean I could turn my acoustic into a jazzbox by mounting a P-90 in the soundhole?

[methodofcontrol]

i had this discussion with a local luthier and he turned me on to the idea of L.R. Baggs IMIX. 2 pickups, mountable circuit box with a a ribbon cable going to a small board w/ 2 volume controls to be mounted near the soundhole. the idea is that you don't drill any holes, you put it all in the guitar w/ double sided tape or velcro. and you find YOUR balance between the two pickups for the sound you're after.
the thing retails for about $270,($230 on ebay for new), but i was thinking i'd like to make something similar. can't find a schematic though, i still need a starting point. anyone have a schem?

[Aura]

I too have been experimenting & building ac.guitar preamps for about a year now.This is what I found from my own experience.
UST's suck!..you'll never get rid of the "quacky nasal sound they produce.
I've tried about 6 types of them to no avail!

As many have rightly pointed out here,mag.pu's are well, what it says on the box!Your guitar will NEVER sound acoustic.

Small back electret cond.mics would be my first choice & the cermaic disc comes a close second.You can buy 20mm ones for about $1 for 5 of them on the E-Bay!A well designed circuit actually sounds very pleasent & picks up all the vibrations from the guitar.I really liked the sound even on my cheapo guitar

I've actually just completed building this preamp which I lifted from www.redcircuits.com under the caption " Tone Control" on page 6. The schematic is in this forum under the thread "Acoustic guitar preamp. But you'd need a high impedence buffer before the actual preamp.I have the buffer design too.A fairly simple circuit which you can add all the bells & whistles to as you fancy!

The Buffer

C1 before Rs = 1uF
R = 4k7 or 2k2
Rf = 10k or 4k7
Rs = 2k2
RL load resistor = 4M7
IC =TL072 or LF353 or any JFET opamp IC only! (do not use any bi-polar ICs. ex;NE5532)

These are the actual values I used/changed to;

Change also to TL072 on the preamp,since the TL062 doesn't have/produce enough current to drive this properly.

You can assemble all this in a small dicast alu.box for better RF/screening...use good quality connecting copper wire like,18-22/0.20 more copper = more bass response/natural sound! & braided screening for the piezo disc.

The total cost would be about $ 10-15 + the casing

[methodofcontrol]

excellent info, aura. thank you! i'll look into that stuff ASAP!