Adcom GFP-750 Modfication Question


Has anyone had their Adcom GFP-750 preamp modified or heard one thats been modified by Stan Warren at Supermods in Eugene,Oregon?
If so, does it make a big improvement?If so, in what ways?
What all does he do to it? Or, am I better off keeping it stock from the factory?
daltonlanny
SUrprisingly Id be interested in what mods he actually does. I cant believe he does any mods to the passive circuit which is almost perfect to begin with. DOes he mess with the active stage? Sound deaded? Whats he charge?Give some details. Website etc....
Ritteri,
He supposedly works on the active stage.Changes the capacitors to Black Gates.How much he charges, I have no idea.I hope someone will tell me.I tried to call but there was no answer.You can call him at 1-541-344-3696.Best times are between 1:00 p.m and 4:00 pm Pacific Standard Time.If you find out anything,please post it or e-mail me.
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.
Hey Lmack,
What all sonic improvements, top-end, midrange, and bottom-end did you gain after you had your former Adcom gfp-750 modified by Stan Warren at Supermods with the Black Gate caps? How substantial were the improvements? Is it worth the trouble of packing it up, sending it out, and paying $150.00 in your opinion? Please describe the sonic improvements in detail.
Black Gate caps give a warm liquidy feel to the midrange from the research Ive done and heard. Downside is break-in time. The consensus is it takes about 500-1000 hours for break-in. $150 may be worth the price if you use the Active Stage. I never needed to when I owned this unit awhile back, I was always in passive mode using all xlr's. ANd as they say, the best pre-amp is no preamp, and the closest to no preamp is a simple passive resistor with minimal traces design of Nelson Pass.