Tunable Piezo Pickup

[rjb]

I just bought an old classical guitar at the local junquetique shop, not even realizing it had a Barcus-Berry Disqis installed.

While searching for info on the Disqis, I bumbled upon this vid of a piezo pickup system with mechanically tunable frequency response.
I have no affiliation with the maker- just thought someone might be interested in the concept.
tunable Acoustic Guitar Pickup System by Peterman - YouTube

Have fun,
-rb

PS- Factoring in the $45 street price of the Disqis, I reckon I paid $5 for the guitar- a 1969 Yamaha GC-7.

[soundguruman]

These type of pickups work OK when you have a preamp and EQ to tune the feedback out.
Otherwise, there is too much squealing / ringing from the resonance of the pickup.
A tunable pickup may help to minimize the resonance, and minimize the feedback problems.
BUT most people have given up trying to use these things for live sound. They work OK for recording in a studio.

[rjb]

BUT most people have given up trying to use these things for live sound. They work OK for recording in a studio.

There is an exception for every rule. AFAIK, Willie Nelson still uses a Baldwin Prismatone in "Trigger". And plugs it into a lap steel amp. I wouldn't say it sounds anything like a classical guitar, though.

I played around a little with the Discis, and it acted pretty much like you would think. Plugged into a little practice amp, it was VERY hot and wanted to howl- had to set volume around "1" and couldn't EQ it to sound good. I don't have a real PA on hand, but tried plugging into the Line-In of a Gemini powered speaker- had to crank the gain full up, but it sounded kinda OK. I might build a JFET buffer & play around with the input resistance get the Discis to consistently play nice.

Have fun,
-rb

PS- I think I'm going to name my "new" guitar Rin-Tin-Tin.

[Guitarist]

He had a good ramble on another video too. Perhaps live you could split the sound right off and send the non-eq'd sound to the board. I'm about to glue some piezos into my acoustic this week and will try his ideas. Hope it works out;!