Hi all
I've had positive result with this circuit:
www.dodotronic.com/public/piezo.png
probably the 10 Mohm resistor could be changed with a smaller one to reduce
noise and distortion
It's simple and cheap and need a further amplifier to reach good results.
Ivano
www.dodotronic.com
2015-02-17 20:00 GMT+01:00 'Jonas Gruska'
[naturerecordists] <>:
>
>
> Hey everyone,
>
> just a short note - I tried the Alex Rice's preamp and I didn't find the
> results to be really good. It was very noisy. I used J201 fets.
>
> Surprisingly, I had much better results with this simple circuit:
> http://www.till.com/articles/PreampCable/images/plugschematic.gif
>
> Now I am experimenting with various configurations and testing various
> j-fets in place.
>
> Impedance converter is a good option too, I bought this one:
> hosatech.com/product/mit-129/
>
> But its performance highly depends on the quality of your preamp - you
> need to crank the gain a lot to get decent levels. And if your preamp is
> noisy...
>
> My Sound Devices 702 handles it well.
>
> Regards,
>
> Jonas
>
> On 17 Feb 2015, at 19:51, Keith Smith
> [naturerecordists] wrote:
>
> Hi, Ben.
>
> Radio Shack sells piezo buzzers for a couple of bucks that are nice and
>
> big. The Schallers can be had at most music stores for around $15, I
> think,
>
> and there are lots of sources on the web, of course.
>
> For *much* better performance you might consider something like this
>
> <http://www.zachpoff.com/diy-resources/alex-rice-piezo-preamplifier/>
> preamp
>
> if you don't mind doing some soldering. Piezo's are high impedance which
>
> isn't a great match for an input expecting to see a low impedance
>
> microphone.
>
> I just use what's known in the music business as a DI (for converting hig=
h
>
> impedance guitar outputs to match with mic preamps). They're just a
>
> transformer in a steel box with 2 1/4" TR (I/O)and one XLR output. The
>
> downside of DI's is that they're usually built for rough stage/road use,
>
> are bulletproof and probably heavier than you want. I use a dual one that
>
> weighs over a Kg. Not nice, but I don't hike far and it works very well.
>
> That does make that preamp I linked to look rather attractive if you want
>
> something light.
>
> I'm not sure what the transformer turns ratio is. Hopefully David will po=
p
>
> back in here with that. Top transformer brands for this are Sowter in the
>
> UK and Jensen in the US & Canada, but you can do OK with less expensive
>
> stuff if you stay away from the obvious garbage. If you got the
>
> transformers on their own, you could make up a stereo pair that would be
>
> fairly light weight with small connectors to suit your recorder.
>
> Either way, use something in there to get a better impedance match. The
>
> audio difference is well worth whatever it costs.
>
> k
>
>
> =E2=9C=BA =E2=9C=BA =E2=9C=BA
> homepage <http://jonasgru.sk>
>
>
>
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