Some things I learnt from Widget...

[boputnam]

1) the ADCOM GFP-750 is a superb preamp. I just installed mine - expecting little or no change. I was at-the-least hoping to alleviate my persistent ground-loop (though tamed, it was everready...). Man, was I :shock: !!

The GFP-750 completely opened-up the sound. Wow. The response was more crisp (immediate) and the bass MUCH more opened. My 4345's have never, ever sounded so open. It was as if they could really breathe...

2) The Hafler's don't approach the capability of the QSC CX-series. Widget and I have unintendedly verged on a nearly identical signal path. The only remaining departures are the amps and EQ. I knew I loved these QSC's - and by improving the preamp, I just got a new stereo... :banana:

Widget - time for a visit! Freddie, you too!!

[Guido]

Thanks Bo for this interesting report.

It brought back an old question.

Does a preamp improve the sound? Isn't it more logic that connecting a CD Player with variable output direct to the amp is better?
I mean of course a high end player with high end potentiometer in the output stage. E.g Harman 7725.

[boputnam]

Isn't it more logic that connecting a CD Player with variable output direct to the amp is better? Sure, and there is a "Passive" option on this, where only the four-gang volume attenuator is in the circuit. Playing around last night, I found the "Active" mode quite pleasing. :coolness:

[scott fitlin]

Thanks Bo for this interesting report.

It brought back an old question.

Does a preamp improve the sound? Isn't it more logic that connecting a CD Player with variable output direct to the amp is better?
I mean of course a high end player with high end potentiometer in the output stage. E.g Harman 7725.The Front end of any system ( preamp ) has a major effect on overall sound!

[Mr. Widget]

Sure, and there is a "Passive" option on this, where only the four-gang volume attenuator is in the circuit. Playing around last night, I found the "Active" mode quite pleasing. :coolness: I have run the Adcom in both active and passive modes (passive is essentially as Guido suggested, your CD player is connected to a pot and then the crossover/amp(s) with no active circuitry). In passive it is obviously quite transparent. I find in general the active mode "stiffens" the bass. It just seems to have a bit more authority.

Hey Bo, we will have to do an amp shoot-out. Maybe during the next round of Project May auditioning.

Widget

[Ian Mackenzie]

Bo, here is a review off the web site, I believe we have nearly identical preamps according to the designer. Welcome to real hifi an I'll bet your 4345s sound better than ever!

Ian

The GFP-750's single gain stage operates without feedback and uses only discrete devices. Nelson Pass, this preamp's designer, believes this circuit offers exceptional transparency and neutrality together with low noise.

He's right. The GFP-750 is not going to put elite preamps like the Krell KRC series or Pass Labs' Alephs out of the running, but it is very, very good. Past Adcom preamps, such as the GFP-555II, did very well for the money but did not approach the 750's degree of refinement and freedom from coloration. In fact, you have to listen very hard to hear the difference between the 750's active and passive modes. (Your interconnects may add as much coloration as this preamp does.)

I found the GFP-750 to be free of the GFP-555II's slight warmth and lack of detail; transients seemed crisper and cleaner, particularly for low-level signals, and the soundstage was more open and detailed. Dynamics were better, and music had more energy and life. The 750's sound was exceptionally detailed, neutral, and pure, without hardness or upper-frequency overemphasis. It came damn close to the sound of some of the best preamps around. If you're used to mass-market electronics, you'll hear the difference immediately.

[Maron Horonzakz]

The ADCOM is a closely guarded secret around here . We dont want the price to go up due to high demand. Ist sound is very very close to my KRELL KBL/KPA... The 750 Is a clear winner. And should be in every bodys stable. The price is reasonable.

[Alex Lancaster]

:rolleyes: And with these posts, watch it go up in eBay.

[boputnam]

:rotfl:

But, I think we can know that at least in this case, the posters are not sellers!