Pickups for a hurdy gurdy?

[mjg]

A mate of mine is building a hurdy gurdy... which is really hard to type without autocorrect getting upset.

He has asked me how he would install pickups to connect to a small amp. 

I'm thinking it will be something like a semi-acoustic?  Small microphone or piezo or whatever.  The instrument seems to have different sounds from different sets of strings, so probably needs pickups in multiple locations. 

Anyway, anyone have experience with this kind of instrument?   

[EBK]

In addition to violin-like sounds (plus an almost bagpipe-like drone), performers can also do some little tricks with the speed of the hand crank to add percussive textures. Very interesting instrument.  Saw a sweet video once of someone layering the sounds of a hurdy gurdy using a loop pedal, so it definitely is possible to wire it up -- somehow.

[Scruffie]

I helped someone who built them in the past, it was a while back but I remember I designed them a 3 channel mixer/preamp for piezo elements, where they located those 3 piezo's though...

[midwayfair]

This question makes me unreasonably happy.

[mjg]

Yeah, it's certainly an interesting instrument.

Scruffie, if you have a schematic for the mixer/preamp, and you are happy to share, can you post that? Save me reinventing the wheel. 

[gordo]

A very cool instrument.  My niece's wedding featured a Hurdy Gurdy and having never seen a real one in action before I was blown away.  The sound was amazing.  He just miked it but sitting directly in front of the thing allowed you to hear the stuff the mike didn't do a good job of capturing.  Very interested to see how this plays out.

[Scruffie]

Yeah, it's certainly an interesting instrument.

Scruffie, if you have a schematic for the mixer/preamp, and you are happy to share, can you post that? Save me reinventing the wheel.

Probably more than you actually need, but sure.

[mjg]

OK, depending on how the guy goes with building his hurdy, I'll post an update if we get it all wired. 

Probably more than you actually need, but sure.

Sweet, thanks Scruffie.  Dumb question.  What do the diodes do before each op-amp stage? 

[Scruffie]

Protects the op amp inputs from voltage spikes above the rails.

[mozz]

https://www.youtube.com/watch?v=7Ql0jGN-F-g&feature=youtu.be