Build An Amp

Putting LDRs right near a power supply is not a good idea as power supply noise gets into the signal. This board allows you to mount the LDRs and run wires from power supply to this board to control the LDRs from a distance. This board also allows mounting the LDRs right next to the RCA connectors to keep the shortest signal length. Another advantage is that once mounted on this board you could try many different power supplies without soldering onto the LDRs again and again or move them from one chassis to another without soldering again and again. The LDRs are fragile and sensitive to overheating. Overheating will either destroy them or change the way they match. Bending their legs to much or in the wrong way can destroy them as well. So soldering them into this board one time protects them for the time that you own them. This board includes a balance circuit so that if you have any issues of channel balance with your LDRs you can trim their reference to ground which will balance that stereo image to dead center. This can be either set and forget on the board itself or you can replace the trimmer resistor with a pot and control balance to your hearts content with a chassis mounted potentiometer. Each board houses 4 LDRs. The two Shunt LDRs and the two Series LDRs. For single ended operation (when you use RCA plugs) you only need one board for stereo. A balanced configuration (has nothing to do with left and right channel balance but refers to using XLR connectors) would need 2 boards. These boards are 60x40mm or about 2.5"x1.5".