Also a second photo of how I temporarily connected the circuit board and components inside my CBG would be helpful. A photo of the component side along with how the battery is connected would be good to have. I think I need to invest in one of those soldering "third-hand" helpers with the two movable alligator clips and magnifying glass to help see what I'm doing. If I had a working digital camera, I would take a photo and post it, but my solder side of the PCB makes me feel ashamed (it's so messy - workmanship-wise). Here's an image file that shows which lead is which for the MPF102: If you are new to FETs and the MPF102, you need to be sure to know which lead is which. For out of spec FETs, you can still use them if you change the values for R2 and R3, but that whole topic is way beyond the scope of this posting. I'm told the specs for these FETs vary widely and that you should buy several in case the first couple are out of spec for this application. You can check by going to the Radio Shack website (google: "Radio Shack" + "components"). Radio Shack has been slowly downsizing the components selection that they offer over the years, so hopefully they still have all the parts when you get around to building this circuit. I have also put together a Radio Shack parts list with current prices. Here are 3 URLs related to the circuit design above: Here is the circuit design I used with all Radio Shack components:
Piezo preamps how to#
I will be experimenting on how to make the piezo pickups less sensitive and where to best locate them on my CBGs. It worked first time, but the two piezo pickups are very sensitive in spite of wrapping them in foam.
It buffers a pair of Radio Shack piezo pickups to drive a 15 Amp guitar amplifier I have. MFP-102 FET using a circuit design I got from the Internet (see URLs listed below) and components I bought from Radio Shack last summer.
Today I assembled my first preamp based on a