Note: the number listed as 'Current Stock' means the maximum number I can build at one time. It may mean that I can send one out immediately, but more often means that I'll need anywhere from three to five days to assemble and test one. See the 'Ordering' page on the thaudio.com website for details.
The Piezo Buffer Mini is an evolution from the now-discontinued Piezo Buffer, a similar unit which was also purple. This version continues the noble tradition of being a buffer for instruments equipped with piezoelectric transducers, while being a good deal smaller and lighter than the original version.
What is the Piezo Buffer?
If you play an acoustic instrument equipped with a piezoelectric pickup, you might have heard something unplesant when plugging straight into amplifiers: a tinny, harsh tone with weak low-end response. That was most likely because of the impedance mismatch between the pickup and the amp. A buffer circuit can help. Refer to the video above for a demonstration of what happens when you use one.
With the TH Audio Piezo Buffer Mini, you'll most likely hear:
the low frequencies that often go AWOL when you try to plug a piezo pickup into a traditional guitar or bass amplifier,
less harshness in the high frequencies, and
a smoother overall response.
The input impedance of the Piezo Buffer Mini is ~= 10MegOhms, to accomodate the very high input impedance of piezoelectric transducers, which tends to be around 5 to 10 MegOhms. I've found that Fishman piezo pickups seem to like 10 MegOhms and homemade transducers, like what you could make from the disc in a Radio Shack buzzer or piezo material from LMI, will respond well to 5 MegOhms but 10 is okay too.
The output signal of the Piezo Buffer Mini won't necessarily be stronger or louder than the input; in fact, much of the time, the output signal will sound less loud. That's because, the Piezo Buffer Mini is, theoretically, a unity-gain device, in other words, a device with a gain value of 1, and as we know, 1 times x is, theoretically, x.
The output impedance of the Piezo Buffer is around 220 kOhms.
Tone controls the high-frequency response of the output. Clockwise rolls off high end.
Inputs and Outputs
The Piezo Buffer Mini has a single 1/4" input and a single 1/4" output.
The Piezo Buffer Mini runs on a 9-Volt internal battery. To replace the battery, disconnect the unit and unscrew the back plate. Carefully disconnect the existing battery from the battery terminals and lift it out of the enclosure. Connect the new battery to the terminals and slide it into the enclosure.
To run the unit on external power, use a 9V or 18V DC supply (center-negative). TH Audio does not recommend running the Piezo Buffer Mini on voltages greater than 18VDC.
The Piezo Buffer Mini features:
True bypass switching
Metal film resistors, 1% tolerance
Lead-free tin/HASL PCB
Heat-treated silkscreened graphics
All TH Audio pedals are handbuilt and tested in the United States of America.