stoic51

Overall Rating
 4 of 5

Value Rating
 5 of 5

Used product for
3 Months to 1 year

Price Paid:  $0.00

Summary:
This is one of the original GFP555s purchased new years ago. I recently pulled it off the shelf to see how it compared to the SP9 Mk II and the preamplifier section of a Yamaha RX-V1500 receiver. I was quite surprised at how good it sounded.

It's still dead quiet on all inputs, is timbrally accurate, dynamically alive, and it throws a very good soundstage, with excellent left-right precision and adequate depth. The SP9 Mk II marginally betters it in depth, but certainly not by much, in unblinded comparisons.

The Yamaha, used as a preamp driving the same Adcom GFA-555ii amplifier, with the Yamaha in Pure Direct mode, compares favorably. I would be hard-pressed in a blinded comparison to discern consistent differences across a variety of source material. A definite advantage of the Adcom is the dual stereo outputs. I use the lab outputs to drive the amplifier directly, the normal outputs to drive the Velodyne sub. This setup, once tuned appropriately, gives excellent results.

So, all in all, the little Adcom GFP-555 does a fine job musically, and it's quiet, runs cool, and is reliable. Sure, if you have thousands of $$$ available, I can see going with a Levinson or such for parts quality and build niceties and perhaps incremental improvements (differences?) in sonic presentation. But for the money, the little Adcom is a terrific value.

twc644

Overall Rating
 5 of 5

Value Rating
 5 of 5

Used product for
More than 1 year

Price Paid:  $90.00 from ebay

Summary:
My rating pertains to the unit re-capped so this may not be a fair review.Anyone reads my reviews they'll see I'm a firm believer in good capacitors.There was a time when I thought Adcom was lousy sounding equipment from what I've owned in the past.Not this 1986 preamp after I replaced every electrolytic capacitor with some bypassed with polypropylene caps which has elevated it to a whole other level in performance.

In stock form it was flat or dry sounding and had crappy Jamicon capacitors in stock form.Now,it has incredible sound which once again proves my theory: great circuit design with the sound being compromised with cheap capacitors.I guess the company has to cut cost somewhere and they did this with the capacitors.Many do this by the way not just Adcom !

Now,it has very clean bass that has a fast tight sound.Not bloaty at all.The midrange has a very relaxed sound.Treble is much cleaner which helps with 2 way speakers.

Frankly,this has turned out to be one of my favorite mid fi preamps I've owned yet and I've had Luxman, Yamaha, and Onkyo in the past.Also, re-capping it has extended the life of the unit.You become so accustom to the sound of your equipment to the point where you dont realize the sound has degraded once this equipment starts aging and caps have a limited lifespan moreso than other parts.

It truly delivers beautiful sound to my ears now and is so much more dynamic.This preamp has quite a simple circuit and no where near the amount of passive compnents vs. other units I've owned.Sometimes less can offer more if the circuit is designed well.

It has tone controls and a loudness they call "contour".The tone controls can be turned off for the purist that dont like "colored" sound.Has phono,cd,tuner,auxillary,and two tape inputs as well.The only thing missing is a tuner but i'm not a radio person so no love lost there.

If you have the means to obtain one of these and put decent quality capacitors in it I doubt you'll be disappointed.In fact,you'll be pleased and I cant put a dollar amount on how much one would have to spend on something new to equal the sound of this now 22 year old preamp.

For anyone interested in what parts I used.Nichicon vr series for the main power supply caps.I bumped up the size to 6800 uf and added Dayton poly caps for better filtering.The rest used in the signal path and other areas were Rubycon zl and Elna Silmic II and some of these Ii added Kimber caps.It made quite the difference !

Strengths:
great dynamics across the board in general.

Weaknesses:
No remote

Similar Products Used:
Luxman tp-114
Luxman c-1000
Yamaha c-40
Onkyo p-304
several others I cant remember

Price Paid:  $160.00 from ebay

Summary:
i bought a bunch of things from ebay,and put them together
as a home setup,all adcom except speakers,i have 2 old sets
of JBL LT100's. 2 GFA55II amps bridged, even tho the speakers can handle only 200 watts continuous,the clarity
and quickness are just uncanny, not even the slightest hum, crackle,rfi,nothing but dead quiet between passages,i have noticed a dramatic increase in musicality from this pre-amp
and have auditioned numerous so-called high end tube models
that didn't sound much better to me. i don't profess to be
a audiophile but i know what sounds good and what is a waste of hard earned money.if you need an inexpensive,very
reliable,quiet,and easy to use pre-amp this is the one.this
is my total investment>>>>>>>>>
Adcom GFP555 pre amp 160.00
Adcom GFA555II amp 475.00 bridged to 600 watts min.
Adcom GFA555II amp 405.00 bridged to 600 watts min.
Adcom GFT555II tuner 55.00
Adcom GCD575 cd player 165.00 single disc with remote
Adcom ACE515 A/C enhancer 75.00
Adcom GFS4 4 speaker selector 35.00
4 JBL LT100 speakers viet-nam vintage= priceless
find a better kick-ass system under 1500 bucks,it's a no brainer

Strengths:
absolute dead quiet,simple operation,tone controls

Weaknesses:
none yet

Similar Products Used:
phase linear, yamaha c70, onkyo R1 pre-amp