Hi Mark,
A reverberated sound has a mixture of the dry source signal and the wet signal from the reverb unit be it a spring, plate or whatever. Woolly almost eliminated the dry signal and used the wet signal returning from the spring as his sound. That's what gives the BJH violins that enormous distance. This was easily achievable with the M300 as the dry signal had a control and the reverb had a seperate one. You just turned down the one and turned the other bugger up!
Best,
Martin