acoustic preamp schematic???

[Greenfuz]

anyone know where to find one of these? any fun stuff that can be done with one?

[Gone Fission]

Which one? A few starting points of popular models:
Image search for Acoustic 360 schematic
Image search for Acoustic 140 schematic

There's a longstanding DIY 360+ preamp kit from Viva Analog http://www.lynx.bc.ca/~jc/DIY360plusKit.html
And I think Dunwich might be doing something with the 140 based on his FB activity.

[new05002]

I am doing a lite version of the Acoustic 140. Converted tone stack into baxandall from SVT. Chopped off some of the circuit to simplify.

[Greenfuz]

oh haha, I probably should have specified this a bit more


I meant like an acoustic guitar preamp, you know one for like piezo pickups and junk

[Gone Fission]

Sorry. That hadn't ever occurred.

What kind of pickup setup to use it with? Any active electronics already in the signal path? I don't even really have the start of an answer, but that would help anyone else get you going.

[Greenfuz]

nope no active electronics or anything, just a parlor guitar with 3 piezo pickups wired to a jack

[Gone Fission]

Standard clean(ish) boosters like the Super Hard On, AMZ MiniBooster or Mosfet Booster, or even LPB-1 or MXR Microamp sometimes do just fine to couple a piezo to a clean guitar amp channel. What you're looking for is something that'll deal with the very high impedance piezo pickup and give a lower impedance output. If you already have something like that, give it a try.

Anyway, some stuff to play with:
http://www.till.com/articles/GuitarPreamp/
http://freestompboxes.org/viewtopic.php ... tic+preamp
http://freestompboxes.org/viewtopic.php ... amp#p33587

BTW, if you have a Fuzz Face with a strong output that'll go above unity at lower gain, sometimes those actually work with acoustic pickups with the gain down and the volume up. Perverse and not generally recommended for fidelity, but a possibility.

[new05002]

You need to have an input buffer with input impedance thats very high before any other circuits. A FET or a OP Amp input buffer can be made with said impedance.