Again, Phil, thanks for explaining all that.
OK, so I think I could come up with a small internal clamp and mount the internal piezo between two pieces of rubber. Perhaps rubber from a bicycle inner tube would be fine. Or perhaps an old rubber gasket, or perhaps even cork. I just want it to hold up over time. Some rubber materials become brittle over time. Any idea which exact material would be my best option?phatt wrote:Some of the earliest barcus berry piezo PU's where simply a G type clamp that mounted on the side of the body of a guitar and (If I recall) you could alter the pressure and position of the PU for different effect on tone and output...
As to the rubber muting tone **Yes** that is the whole idea as these piezos have a huge hi frequency response and direct mounting can be problematic and cause all sorts of problems,, one being massive feedback...
My bridge piezo is sandwiched at the base of the archtop bridge, with epoxy. Now I understand that I would have been better off using some kind of material that becomes like rubber when it dries up.phatt wrote:For guitar the most common setup now is to have the piezo element directly under the bridge bone which maximizes the pressure and hence they have substantial output signal. these are often shrink wrapped giving just a little cushioning which helps even out the ride,,,
Can anyone think of a material that I can handle like glue and then dries up into rubber?
The article you linked to says...phatt wrote:They do of course have a completely different response to mag PU's and a lot of circuit tricks are still needed to wipe off excessive hi frequency response...
Good PU info here;
http://www.ozvalveamps.org/pickups.htm
Am I understanding this correctly..? I could try adding an internal cap of about 10 times the capacitance of the piezo, and it should be connected in series.If we assume as above that the [piezo] pickup has a capacitance of 500pF, then connecting a capacitor of say 10 times that value, 5000pF will cut the signal to about one-tenth (one eleventh actually) or a bit more than -20dB compared to the unloaded output. One volt peak from the pickup becomes about 100mV peak at the amplifier which is similar to the output of a magnetic pickup anyway, so this shouldn't be a problem.
But two capacitors in series like this acts somewhat like a transformer which results in a better match to the amplifier input resistance, hence less low frequency roll-off.
Is that correct?
Thanks...