Amp/Preamp Asylum: REVIEW: PS Audio Cullen modded GCC-500 Amplifier (SS) by jonbee

Model:	Cullen modded GCC-500
Category:	Amplifier (SS)
Suggested Retail Price:	$5700
Description:	Modded Gaincell/Icepower Control amp
Manufacturer URL:	PS Audio
Model Picture:	View

Review by jonbee on May 13, 2010 at 15:59:35
IP Address: 67.139.104.162 Add Your Review
for the Cullen modded GCC-500

I've been fascinated by the new technology amps for a number of years. My last conventional amp was a Conrad-Johnson MF-2300A, a powerful amp that was not the last word in finesse. I replaced that with a Bel Canto eVo 200.2 nearly 10 years ago, and while I found that amp to be not very satisfactory, the lack of coloration intrigued me. I've since owned the PS Audio PCA2/HCA2 stack, a GCC-100 amp, a GCC-250 amp, several Tripath amps including a battery powered RWA 30.2 clone, a gainclone, a couple of Panny receivers, and a couple of Sony all digital receivers all in use in one or more of my systems. While they all had drawbacks, sometimes showstoppers, they all sounded much better to me than their conventional AB counterpart amps at similar price points.
I have owned a GCC-250 for a couple of years, and I've enjoyed its neutrality, power and control, its efficiency and cool running, flexibility and compact size. It and the GCC-100 I had previous were absolute rock solid reliable performers. FWIW I found the GCC-250 to be a notably better perfomer than the 100. The 250 has a smoother, more natural mid and top end than the 100 and much better lower mid and bass dynamics and definition. A sweeter, more powerful and ultimately more musical sound.
What sets the GC amps apart from other Icepower amps is that PS Audio matches the Ice mods with a "Gaincell", which acts as a volume control and switcher. Instead of adjusting the input level to the modules, the gain of the modules themselves are adjusted, so there is no active stage or volume control ahead of the Ice modules. A good idea, in my book.
Comparing my system to those of my audio friends, most of whom own much more expensive amps, mostly tube or SET, offered some insight into the GCC sound. While offering some stengths none of my friends' amps offered, such as massive dynamic drive, neutrality and quiet, the weak suit of the GCC was also clear- the inside detail, depth, ambience and space between instruments was not as sharply delineated. The top end also seemed a bit rolled off.
I was aware of the Cullen mods for the GCC amps. Rick Cullen (who also makes Wyred4Sound gear) manufactured the PS Audio amps, and knows them inside out. The top mod, which costs $1200, mostly rebuilds the GainCells with higher spec parts, upgrades some parts on the IceModules, and upgrades the wiring and input and output connectors. Cullen advertises that the improvments are in just the areas I was looking to improve.
I ran across usch a modded GCC-500 at a good price, and decided to see how much the mods improved things. The GCC-500 moves up to the well known Icepower 1000asp modules, spec'd at 1000 WPC into 4 ohms.
I can honestly say that the improvement was substantial, in nearly every way. The haze between instruments was stripped away from top to bottom. Imaging, depth, ambience are now truly remarkable. The top end is more extended and delicate, and the bottom end definition, clarity, slam and impact all take a good step forward. The low coloration is lower yet- squeaky clean really- something not everyone and every system will see as a good thing.
For me this amp now has everything I want- the power and drive for anything, but with the inner separation and delicacy you get in a good tube amp.
One of my friends has a Shindo SET stack that cost about 4x as much. I still give it the nod for ultimate depth and 3-d imagery, but now the GCC does stand up pretty well in those areas by comparison, while offering major horsepower at the same time.
The best amp? Of course not, but with today's used amp prices, you can have a truly excellent amp for well under $3k with the mods, and that is real value. I'd recommend that anyone who owns a GCC who wants to move up should give the Cullen mods option serious thought.
I love this amp. As always, one size cannot fit all and matchups rule!

Product Weakness:	Very clean and uncolored, no added warmth or burnishing. May not make a good match for those whose systems need that kind of thing. Out of production.
Product Strengths:	Powerful, explosively dynamic, great depth, soundstaging and imaging. Very neutral. Uses minimal power except when called on. Well made. Relatively inexpensive. Bulletproof.

Associated Equipment for this Review:

Amplifier: Review amp
Preamplifier (or None if Integrated): none
Sources (CDP/Turntable): ModWright/Sony 9100 Sig. Truth CDP
Speakers: VMPS RM-30, Volent VL-2, ACI Force XL subs
Cables/Interconnects: Clear Day Silver, Vertevarius Copper, Anti-ICs
Music Used (Genre/Selections): lots
Room Size (LxWxH): 16 x 19 x 8
Room Comments/Treatments: Lots of glass- eats bass
Time Period/Length of Audition: 2 weeks
Other (Power Conditioner etc.): PS Audio Quintet
Type of Audition/Review: Product Owner

Amplifier:	Review amp
Preamplifier (or None if Integrated):	none
Sources (CDP/Turntable):	ModWright/Sony 9100 Sig. Truth CDP
Speakers:	VMPS RM-30, Volent VL-2, ACI Force XL subs
Cables/Interconnects:	Clear Day Silver, Vertevarius Copper, Anti-ICs
Music Used (Genre/Selections):	lots
Room Size (LxWxH):	16 x 19 x 8
Room Comments/Treatments:	Lots of glass- eats bass
Time Period/Length of Audition:	2 weeks
Other (Power Conditioner etc.):	PS Audio Quintet
Type of Audition/Review:	Product Owner