Derived from a Rod Elliott design (https://sound-au.com/project176.htm). A fully balanced, full differential audio amplifier. U1 is an NE5532 but is a universal dual op amp footprint if you want to use something else. Connectors are standard 0.1" headers or wire directly onto the board with the pin holes. C1 and C2 are polarized small caps 1206 size or better, MLCC ceramics of at least 4.7uF. R5 and R6 are 0805 100 to 200 ohms. C3 and C4 are 0805 ceramics 0.1uF. R1-R4 are dual 10K Vishay MPM2002A parts in SOT-23 packages. Use +/- supplies appropriate for the op amp rating chosen and rate the cap voltages accordingly. C5 is a small disc ceramic of 100-220pF for RF suppression. Make this an NP0/C0G type. See Rod Elliott’s description on his web site. With the specified resistors, the CMRR of this amp should be quite high (>80dB) over the audio range. Elliott recommends a 0.1uF cap across pins 4 and 8 (-Vee to +Vcc) to keep this circuit stable but the caps now used which are ground returned should be as effective.

The silk screen on the back of this board says Steve Elliot but the correct reference is Rod Elliott of Elliott Sound Products or ESP. It has been corrected in the source files which I have not uploaded the OSHPark.