I just got my EP-PRE, a great reproduction of the circuit in a EP-3 echplex, by clinch FX. Anyone else have one yet?

It definitely influences the tone, seems to fatten things up in the usuable guitar frequency range 200hz to 8khz and has a slight roll off in frequencies in the extreme highs and lows. It also has a cool 3D depth like effect due to the phasing of the circuit.
Result? Well when I push it with my vintage MXR micro amp into my Stage Hog, it gets closer vintage Van Halen like tone. I will try to get some clips out.

You mean like brown sound? What guitar are you using? What setting are you using on the Micro Amp?

a brown sound is achieved by reducing the supply voltage to a Marshall amplifier with a variac.