Adcom GFP-750 Modfication Question

Daltonlanny is correct: the only mod Stan Warren does is to the active stage, replacing the stock capacitors with Black Gates. The improvement is significant: it brings the active mode very close to the renowned quality of the passive mode. The cost was about $150. Stan thinks that the Nelson Pass design is excellent and in need of no further modification. I've just sold mine, since I bought a used Pass X2.5. The price for performance ratio of the Black Gate modified GFP-750 certainly beats that of the Pass, though I'm very pleased with the Pass, which is clearly better in absolute terms.

Daltonlanny,
Ritteri has succintly and accurately described the added "warm liquidity" to the midrange. Further, I heard less grain throughout, which resulted in a smoother, more relaxed presentation, especially top-end, with no loss of detail. While the Black Gates did take some time to break in, I started hearing obvious improvement within a week, and not much more improvement after two to three weeks--though I had my CD player running through it during much of this time, I would at least halve the break-in time Ritteri suggested to 250-500 hours. Yes, if I wasn't clear before: the $150, trouble, and wait was worth it. (Stan also did a great job handling the unit, leaving no external trace.) In my experience and for my listening preferences, there was "gain" and almost no loss in using the Black Gate active mode as compared to the renowned passive mode.