This is a Chu Moy headphone amp I made. I got the PCB design from Guzzler from Head-Fi and the original design is very popular and is here. I changed Guzzler's layout so I could use a Taiwan Alpha pot on the PCB. These pots a high quality (some say better than ALPS blue velvet) and are available from Jaycar. You can see the thread here. I also made a DIY Brown dog adapter so I could use two OPA627 single opamps in a dual opamp socket.
Build Accurate LC Meter and start making your own coils and inductors. This LC Meter allows to measure incredibly small inductances making it perfect tool for making all types of RF coils. LC Meter can measure inductances starting from 10nH - 1000nH, 1uH - 1000uH, 1mH - 100mH and capacitances from 0.1pF up to 900nF. The circuit includes an auto ranging and reset function to make sure the readings are as accurate as possible ... [more]