Advice on Ceramic transducer pickups needed

[Jimothey]

Hi 

 

I’m thinking of making a slimline corvette inspired acoustic bass I’m going to make it about 40mm thick so I can’t fit a preamp to it, I know it won’t be very loud acoustically but I’ll only ever play it through a PA 

 

I’m thinking of fitting a ceramic transducer pickup under the saddle (Artec or similar) can I wire it up passive or do they need to be active? Also I know with disc piezo pickups if you solder a 0.1pF cap on the jack socket it takes some of the shrill tones away is that the same for a Ceramic one aswell? 
 

Any advice gratefully received 👍🏻

Edited June 8, 2024 by Jimothey

[itu]

It is very common belief that piezos sound brittle. The reason is that the ceramic and the first electronic stage form a high pass filter, if the input impedance of the first stage is not high enough.

 

To get the best out of the piezo, a buffer really helps to tame any brittle sounds. It widens the low end just like the size of the ceramic. A cap will cut highs, but I would rather use a good buffer, and eq the sound later in the amp or an fx board.

 

A buffer has to be with hi-Z input (Mohn to Gohm area). Try a few and find your favourite one. Some amps can eat piezos easily, some fx are also effective. Still the buffer is the thing here.

 

If you have a friend that understands any electronics, a modern opamp, or FET can make wonders and does not cost a lot. Usually the box and the connectors are the most expensive parts. Net is full of examples.

 

https://www.instructables.com/Hi-Z-Opamp-Piezo-Buffer/

http://www.scotthelmke.com/Mint-box-buffer.html

[lemmywinks]

I used an analogworkshop piezo preamp in one of my piezo equipped basses, it's just 40mm x 26mm x 10mm so should fit in anything.

[Jimothey]

Thanks for the advice I think I’ll just make the body thicker and just use a spare Fishman preamp I’ve already got 👍🏻

[itu]

It is fine to put that preamp outside your bass, if the space is limited. Recommendation is to put the preamp as close as possible to the ceramic but I haven't have any issues if the buffer has been 3 m away.