JC3+ is a bit more extended in the treble, but slightly flatter overall in presentation. It lacks some of MyGroov’s bouncy fun factor, but is a more solid no nonsense preamp. It’s almost like an instrumentation tool. Gets out of the way and showcases all of the other components in the system. John Curl is a legend and a master circuit designer. He's been perfecting phono circuitry since the 60's.
If anyone’s interested, I have the original Parasound JC3 (not the +) for sale in mint condition. PM for details.