SOLD - FS Adcom GFP 750 preamplifier - SOLD

FB101 · « **on:** 9 Nov 2008, 07:14 pm »

The Adcom GFP 750 preamplifier probably does not need any introduction for most; over the years this fully balanced design by Nelson Pass has built some sort of a cult.
It is truly far better than its price ($1500 when last available) would lead you to believe and I doubt you can find a fully balanced preamplifier at this price from any other brand.
One of the unique features is the active/passive switch which allows to bypass all active circuits and turn the GFP 750 in a unity gain pre-amp.

It has balance, tape loop, processor loop, mono, and phase inversion - all the bells and whistles you may desire.

Sound wise it is tremendously detailed and very dynamic with a very open sound. Great staging/imaging as well.

I bought this unit 2 months ago to pair with my Genesis GR360 amplifier but it was not a lucky match - the GR360 needs something sweeter / warmer (to my ears) while the GFP 750 is very open and sounds similar to the newer Parasound pre-amps - it is not cold or bright, but I think I will go with tubes before the GR360 for best balance of qualities. It will be a great match for a slightly dark amp or speakers that need an injection of micro and macro dynamics.

The pre-amp is in great shape (it was rated 9 on AudiogoN when I bought it but it should in all fairness have been rated 8 due to some small marks on the upper case). I do not have the box or manual but I have the original remote, fully functional.

I am asking for $720 + shipping and would prefer paypal payment but money orders are Ok too.

I have put pictures in my gallery but the scratches look worse on the pictures than in reality due to lighting - thanks for looking

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=1634&page=1

FB101 · « **Reply #1 on:** 14 Nov 2008, 12:34 pm »

Up we go.

ted_b · « **Reply #2 on:** 14 Nov 2008, 01:09 pm »

I had a GFP 750 for many years. It is a sleeper, a real gem of a preamp. The best product ever made by Adcom, and the best pre I've ever owned under $1000.

FB101 · « **Reply #3 on:** 14 Nov 2008, 02:10 pm »

I agree with you, there is little available in this price segment that comes close to what this pre-amp has to offer. I will be going up in price to find a replacement that mates better with my main amplifier - but if I don't find a buyer I'll just keep it and experiment to find a nice amp for it that will work in one of my other systems.

That's the joy of too many toys

FB101 · « **Reply #4 on:** 20 Nov 2008, 12:09 am »

Up for price reduction.

FB101 · « **Reply #5 on:** 29 Nov 2008, 08:10 pm »

Last week-end before AudiogoN.

randers1ac · « **Reply #6 on:** 5 Dec 2008, 09:20 pm »

Hi FB101 - have you sold this yet? I missed your initial posts because I just found this site in early December. I went to Auidogon but haven't seen it.

FB101 · « **Reply #7 on:** 5 Dec 2008, 10:54 pm »

Still available and still at the same price (which is a bargain compared to the other GFP750's currently listed on A'goN). I have not had a chance to list it there yet. If you're interested let me know and I won't rush putting it up.

randers1ac · « **Reply #8 on:** 5 Dec 2008, 11:25 pm »

Hi FB101, definitely want it. New to this, so I'm not sure how to proceed.
thanks, Ross

FB101 · « **Reply #9 on:** 6 Dec 2008, 12:00 am »

Ross, I sent you a PM

Russell Dawkins · « **Reply #10 on:** 6 Dec 2008, 12:23 am »

Frederic - in your first post you say it has phase inversion. How do you accomplish this?
I have had this preamp for 5 years or so and have never yet been able to invert phase. I would love to be able to!

Russell

FB101 · « **Reply #11 on:** 6 Dec 2008, 12:45 am »

The knob on the left has 3 settings:

Stereo, reverse, mono - Stereo outputs signal in the same phase as the source, reverse outputs signal in inversed phase and mono obviously outputs a mono signal. aa

Russell Dawkins · « **Reply #12 on:** 6 Dec 2008, 12:51 am »

I believe you will find that reverse refers to channel assignment, not phase, i.e., in "reverse" left becomes right, but the phase stays the same. aa

FB101 · « **Reply #13 on:** 6 Dec 2008, 01:01 am »

That has not been my experience - has your unit been modded?

Check the manual below - it clearly states the reverse setting inverts phaze and that's what mine does.

http://www.adcom.com/data/manuals/gfp_750manual.pdf

Russell Dawkins · « **Reply #14 on:** 6 Dec 2008, 01:42 am »

I beg your pardon. I just checked my manual and it reads exactly as yours does on the top of page 3. This is very strange.

I bought the unit new, about 5 years ago and I remember being hopeful that at last I had phase invert capabilities in hand, as I was told by the salesman (they had to order it in). When it arrived and I tried it out, my heart sank when I discovered that it functioned as all old time receivers or preamps used to - the mode switch did the usual, but did not invert phase - it simply sent the left input to the right output when in "reverse" (easily heard, of course).

I remember phoning Adcom at the time about this and another issue (tracking between channels at various volume settings) but I honestly can't remember their response, except that I completely abandoned hope that I had phase invert in hand. Sure enough, when I use this knob, the channels are reversed - no mistaking it with most jazz recordings or orchestral.

As I say, I bought mine new and it has not been touched. Is yours hooked up? Can you confirm that it does not reverse left and right when you select reverse??

FB101 · « **Reply #15 on:** 6 Dec 2008, 01:54 am »

Mine works as expected - it is not hooked up right now but I tried it when I bought it and there was no inversion of L and R channels. I listen to a lot of classical orchestral music so it would have been an immediate give away.

In my room I am actually listening in reverse mode for better bass integration so I would have picked it up quickly.

I'll give it another try but I am 99% confident mine works as a phase inverter not channel inverter.

ted_b · « **Reply #16 on:** 6 Dec 2008, 03:18 am »

That's how mine worked (as per the manual)...reversed absolute phase.

Russell Dawkins · « **Reply #17 on:** 6 Dec 2008, 07:08 am »

Well I used mine for mixing and mastering my recordings and it sure would have been an advantage to me if mine had had that function - I never needed to reverse L&R, but I would really have liked to have been able to flip phase.
I have a query in to Adcom customer service, but unfortunately this came to my attention just an hour past the end of business hours on a Friday, so I'll be lucky if I get an answer on Monday - but I am curious!
Incidentally "reverse" in the context of mode switches has always in my prior experience meant reversing L&R. The word "invert" is usually associated with polarity, as in the Lavry DA 10, for example:
http://www.lavryengineering.com/productspage_da_10.html
(click on image to read front panel text). The conventional symbol for this is a zero with a diagonal strike-through (ø), like a European zero. Better mixing boards have this in the mic/line preamp section of each channel strip - a "ø" with a push button beside it indicates polarity invert.

mfsoa · « **Reply #18 on:** 6 Dec 2008, 05:36 pm »

Wow, that (phase inversion) would be the weirdest implementation of the terms "Stereo Reverse Mono" on a single control knob I've ever seen. Hard to even imagine that it would reverse absolute phase, yet that's clearly what the manual says

Maybe the people wrting the manual weren't in contact with the people designing the faceplate

I'm interested to see what the outcome of this is

-Mike

mfsoa · « **Reply #19 on:** 6 Dec 2008, 06:26 pm »

Now I see that they define this function both ways in the manual, on p. 2 and p. 3