using R.G.'s onboard buffer with piezos

[bluebunny]

I was looking for a simple onboard preamp or buffer to hook up with a piezo under-saddle transducer.  How would R.G.'s onboard buffer suit?  I really like the simplicity (and it's all I need), but I've not been able to find any mention of it being used with piezos.  Would the input impedance be high enough?  If not, could it be tweaked easily?

[vigilante397]

Seems like it could be tweaked easily enough. I plan on breadboarding this over the weekend (read "sometime in the next 6 months when I have free time") and playing with it to find the ideal sound for my electric, then I was thinking about trying it with the acoustic as well. If nobody gets to it before me I will let you know how it goes

[PRR]

> Would the input impedance be high enough?

Yes.

[bluebunny]

Thanks Paul.

[ubersam]

If you want something even simpler, a JFET buffer works pretty well. I replaced the onboard preamp in a friend's Epi acoustic and we both liked it better, except there was no quick way to adjust the tone/eq/volume as before.

[Eddododo]

http://personalpages.tds.net/~fdeck/bass/quickand.pdf
LOVE this one... it was the first active circuit i ever built, and i have built and used several of them. 2n5486 is my favorite choice.. you can fit this anywhere

[jatalahd]

+1 for Deck's quick-and-dirty buffer. If you want to keep the low-end response decent even on a guitar, you'll need to get close to that 10Meg input impedance. For example, even with 1Meg input impedance your low-end will be clearly dampened. A FET buffer is suitable, because its intrinsic input impedance is more like 100Meg, so all you need to do is to select the gate-to-ground resistor to fix your input impedance.

[bluebunny]

Thanks for these suggestions too. I've also found the piezo article on Jack's blog, which looks interesting.

Edit: added URL to Jack's blog.