Piezo Noise & Passive Circuits

[psw]

Anyone know of a way to suppress handling noise and microphonics in piezo pickup designs?

Also.

I've seen in this forum comment that combining piezo's with pickups without some preamplification causes problems when combined with magnetic pickups (loading, tone shaping?) Can these problems be addressed passively. (eg caps to roll off the high end).

If it must be active has anyone thought of using a very low drain circuit running off a little lithium cell. I believe they can last up to 10 years. (Or hearing aid technology)

cheers

psw........................................ ........................................

P.S. For my latest success with my sustainer prototype see the thread Sustainer Ideas

[lovekraft]

Anyone know of a way to suppress handling noise and microphonics in piezo pickup designs?

You'll have to shock-mount the transducer, just like any other microphone element. Foam suspension, springs, rubber mounts, whatever works.

If it must be active has anyone thought of using a very low drain circuit running off a little lithium cell. I believe they can last up to 10 years.

I'm afraid you'll have to use some kind of active buffer - a single JFET would work fine. Take a look at Don Tillman's Preamp article for a basic circuit, and while you're there, check out the Preamp Cable article for ideas on phantom power (no onboard battery).

[Saber]

The purpose of a piezo pickup is to pick up vibration from the guitar top and strings, so I think that shock-mounting or mechanically isolating it in any way would just prevent it from doing its job.

[lovekraft]

The purpose of a piezo pickup is to pick up vibration from the guitar top and strings, so I think that shock-mounting or mechanically isolating it in any way would just prevent it from doing its job.

Obviously there's a trade-off involved, but do you know of any other way to "...suppress handling noise and microphonics...".? The ideal would be to mechanically couple it (as much as possible) to the desired sources of vibration while isolating it (as much as possible) from the sources of "noise". Sorry for not making my intent clearer.

[Kevan]

Anyone know of a way to suppress handling noise and microphonics in piezo pickup designs?

Also.

I've seen in this forum comment that combining piezo's with pickups without some preamplification causes problems when combined with magnetic pickups (loading, tone shaping?) Can these problems be addressed passively. (eg caps to roll off the high end).

If it must be active has anyone thought of using a very low drain circuit running off a little lithium cell. I believe they can last up to 10 years. (Or hearing aid technology)

cheers

psw...........................

Yes, there is a way.

In my J-Custom RG7-CST, they arranged the piezo element polarity similar on ever other saddle. Example (7-string):

B= +

E= -

A= +

D= -

G= +

B= -

E= +

On the preamp, there is a phase reversal switch, so each of those strings can be "flipped". This also helps if you're having phasing issues when running piezo and magnetic at the same time (a blessing when recording).

The Double Edge double-locking trem system is built by Ibanez and LR Baggs. Im not sure if they do it in their stock models, but they did work with Ibanez on these trems, and you can barely hear your hand resting on the bridge.

It's a pretty nice setup and works really well.

[psw]

How about a transformer or something? I'm still not getting the need for a buffer when I get a quite a strong signal from it.

Here's the thing. I tested an idea for a magnetic/piezo hybrid. Basically a piezo element that is vibrated by the magnet field on a guitar string.

I tried attaching it by double sided foam tape but this flexability allowed even more vibration to occur. Perhaps I should have glued it down or perhaps used silicone for a little less spring. The next time I work on this I'll perhaps try even smaller piezos.

Does anyone where you can get piezo film?

[lovekraft]

If you're still looking, here's a Stratoblaster variant that uses a CR2032 3 volt battery and a tiny PCB - the current draw (according to the article) is about 30 uA:

SIMPLE BUILT IN PREAMPLIFIER

Sorry about the cheesy translation - My Russian is nonexistent, but you should be able to get the gist of it.

[psw]

ThanksLK

Just the sort of thing I was after.

I really just want to buffer some pickup ideas I have.

Remarkable translation me thought:

"Of theories not it will be. Continuous practice"

Good advice for us all

psw

[truerussian558]

i might be able to fix it up wheres the original site

[lovekraft]

The original article, courtesy of Igor's Amps. He's got a bunch of cool stuff on his site, but of course it's mostly in Russian. I speak no Russian, so even the Babelfish transalation is better than nothing. There's a cool little one tube preamp that he's translated with a voltage multiplier power supply that looks way cool!

[truerussian558]

in the beginning it sais , there will be no theory, just practice

oh and rioght before the picture of the board its not pay its board, its written the same way in russian so it must have gotten confused

skhemki is schematic by the way

one heck of a translation you got seems like the smurfs wrote it

[lovekraft]

You ought to see what it does to German! Seriously, it's all I could find, but it appears to translate words literally from a fixed dictionary, with no allowance for context, idioms or slang. You just have to learn to think like a stupid machine (no problem for me, I was in retail for years). Oh, well, at least the schematic doesn't need any translation.