Regurgitator PCB can be used to convert any balanced or unbalanced signal in to balanced or unbalanced signal out with trim pot control from -10db loss to +18db gain.
PCB comes as Single, Dual, or Quad PCBs
Single PCB measures 58.2mm (2.3") x 25.4mm (1"). Dual PCB measures 58.2mm (2.3") x 50.8mm (2"). Quad PCB measures 58.2mm (2.3") x 101.6mm (4")
Regurgitator Audio circuit by Rob Squire. Power circuit & PCB by Joe Malone.
Rob's test figures using a 5532 on +/-18V rail
Max balanced output is +29dBu or +26dBm
Noise when trimmed for unity gain is -93dBu unweighted ( this is on the bench with no case and there is a small amount of 50Hz being picked up )
Noise when trimmed for +18dB gain is -73dBu unweighted ( as above )
Noise when trimmed for -10dB gain is -102dBu ( this is the limit of my analyzer)
Distortion at unity gain and +10dBu out is 0.002% ( this is the limit of my analyzer)
CMRR is -70dBu at the unity gain of test unit with normal 1% resistors.
Input Z balanced is 15K and unbalanced is exactly 7.5K looking into either the hot or cold leg.
So this achieves the aim of high CMRR and impedance-balanced input. Unlike a normal diff amp where the input Z is different into each leg.
