Wow! Adcom has released the “new” GFA-555SE. They call it “A Classic Reborn” - who can argue.


Modification Strategy: Our venerable LX mod for your Adcom amplifier has changes in feedback circuitry (Silmic II in Elite) which improves bandwidth, dynamic range and bass solidity/power. The bias circuit uses a new and better capacitor with an added high quality bypass capacitor. Input and output filters are improved with far better parts. Each small-value (picofarad) high frequency stabilizing capacitor is optimized for audio quality.  Each power supply capacitor has an added bypass capacitor with double bypassing in Elite. Elite and higher models have superb power rectifiers in the main power supply. We have found the finest soft-recovery diodes superior in naturalness and dynamics. 


The Sound: LX is much more natural, sweet and liquid. Soundstage is much more open. Imaging from top to bottom is more predictable, i.e. instruments come from stage locations that seem more accurately positioned. Gone is the brightness, etched quality and bass inaccuracies. Perceived dynamic range soars! The Elite version is even more defined with solid bass extension and silky extended high-end detail, a definite improvement in resolution and definition. We install superb sounding soft-recovery rectifiers and added power supply bypass caps. The mids have superior timbre, texture, clarity and musical naturalness.  Highs are more natural and clear.


See The Absolute Sound® #55 for the LX modification review. If you want to see this review go to  www.theabsolutesound.com and ask that this review be made available for download from their web site.



LX Mod

LX mods are for all stereo, mono and multi-channel Adcom amplifiers, including all "555", "585", "5800", "5802", etc. 

$399 installed for all early model Adcom stereo amps, except for the following listings - $499 for GFA-5500/5800/5802, $629 for 4-ch amps, $699 for 5-ch. amps, GFA-565 LX mod is $599/mono pr



LX Elite Mod

$599 installed for all early model Adcom stereo amps, other items listed below – for GFA-565 $799/pr, $899 for 4-ch amps, $999 for 5-ch amps, $699 for 5500, 5800 & 5802



LX Mini-Platinum Mod

A mix of Takman CF and highest quality Dale resistors, in strategic locations, offers superior naturalness and clarity. Some added "double bypass" caps are used in critical locations. Add this upgrade to an Elite mod for even more natural sound. Add $250 to stereo Signature mods, $300 to mono pair pricing.


See power supply options by visiting these pages - Amp Options and PS-200

See our "Connector" page for hi-quality RCA connectors and binding posts that we can install for you!


Adcom Amplifier Modifications