Author Topic: Piezo Buffer  (Read 5962 times)

septi0

Piezo Buffer
« on: February 27, 2014, 06:41:42 AM »
So here's the deal: I just bought a piezo buzzer to put it into my electric guitar.I putted it under the bridge and so far it sounds decent so I decided to make a buffer for it.Piezo's ground is connected stright to the bridge, so my guitar share the same ground.I fund this schematic -> http://www.scotthelmke.com/Mint-box-buffer.html that I am planning to implement.Cound anyone please look at the schematic and to my schematic to check if I made it ok?My schematic is this-> https://lh4.googleusercontent.com/-D2yg8EO8ae0/Uw8iMwuCubI/AAAAAAAAA0k/dWVlRsrI1dw/w987-h387-no/Board.png
The ideea is that I don't know if I still need to connect the ground at the input and at the output...I mean...If i connect the piezo ground like I did in the schematic where will the output ground  be connected, so that all of my pickups share the same output jack?

septi0

Re: Piezo Buffer
« Reply #1 on: February 28, 2014, 12:15:17 PM »
I see that not alot of people tried this.

Regarding to the original schematic could anyone please tell me if I couldn't find a 22M resistor is ok to put two 10M resistor in series to get 20M?I mean if instead of 22M I put a 20M resistor what could happen?Also that 1pF condenser can be replaced with a 1.2pF?I can't find anywhere a 1pF condenser.

In theory what are the consequences of putting a condenser with a slightly bigger value and a resistor with a slightly smaller value?
« Last Edit: February 28, 2014, 12:18:35 PM by septi0 »

bluebunny

Re: Piezo Buffer
« Reply #2 on: February 28, 2014, 05:33:21 PM »
Regarding to the original schematic could anyone please tell me if I couldn't find a 22M resistor is ok to put two 10M resistor in series to get 20M?I mean if instead of 22M I put a 20M resistor what could happen?Also that 1pF condenser can be replaced with a 1.2pF?I can't find anywhere a 1pF condenser.

You could indeed string two 10M resistors together (I'm assuming you've subbed a BF245 in lieu of the 2N5457?).  And using a 1.2pF capacitor won't make any difference you can hear; as the notes say, it's for shunting RF to ground.

BTW, the layout looks OK to me, assuming you're OK with making cuts in the tracks *between* holes, and assuming you're using tiny caps (ceramics/MLCC should be small enough).  You've also got a couple of places with two wires in one hole.  You might find that tricky to do in real life.
« Last Edit: February 28, 2014, 05:38:13 PM by bluebunny »
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septi0

Re: Piezo Buffer
« Reply #3 on: March 01, 2014, 02:00:29 AM »
Thanks.I made it that way because I want to put that circuit inside my guitar so space saving is vital.I've completed the circuit with my topology and with hard work I was able to stick to the dimensions.

And yes, I used a BF245.

septi0

Re: Piezo Buffer
« Reply #4 on: March 01, 2014, 09:25:19 AM »
So...I finished it up and it works like a charm.If is anyone interested I made a picture of the board. https://lh3.googleusercontent.com/-Jop7ZzBhKow/UxHtFe10_9I/AAAAAAAAA2M/FWJGKMiCqBk/s800/C360_2014-03-01-10-36-48-810.jpg