Here are some boards I designed that you can buy for your projects. Boards are £5 each plus £1.50 P&P for uk postage.
email parenthetical at this domain to get more info and arrange payment
Documentation and photos are in progress, but will take some time to finish as there's a lot to do
Most of the pcbs here so far are for mics, but there are also a buffered balanced volume control, a headphone amp, and some mic preamps.
CAUTION Page is being reconfigured, there may be errors, missing links, and messy formatting until I get it all converted to the new system.
Click on the code for full page on each board.
|A simple opamp mic circuit
|A dual opamp mic circuit
|dual opamp both pins driven
|An opamp mic with transformer
|single opamp & tx
Microphone Preamp PCBs
|Ricardo's 70s mic amp
|THAT 1512 & 1646 with DC servo
|very clean chip mic pre
Misc other PCBs
|Buffered balanced volume control
|THAT1200 & 1646
|parallel opamps eg NE5532