Gentlemen,

I have just received the Adcom GFA 555 II back from being modified as stated before. Arif, the modifier, threw in for free addional tweaks like "snubbing" capacitors on the bridge rectifiers and new AC socket because he got carried away with the modification process.

I hook the amp up to drive the woofers on VMPS RM40 speakers in a biamp configuration. Wait 30 minutes for it and the tubes in the other amp and preamp to warm up. The needle hits the groove, and voila, the sound is to so seductively good that I stay up and listen to every record I have......

Actually, it is more a function of biamping then mods on the Adcom amp. With just 100 watts tube amp, everything was just too thin. Bob Dylan sounded like what Robert Zimmerman must have sounded before puberty. 100 watts just is not enough to move the huge magnets on RM40. Good 300 or 400 watts of steady power are needed to drive the woofers well.

What I noticed with the modification is that it is in absolute control of the woofers -- no blaring booms. There is no hint of rolling off or muddied sound. Rock solid bass really improves the overall tonality. In addition, the adjustment on the sensitivity really helps. I had the speaker level control of the highs and mids way down to keep with the bass before. Now, they are in neutral positions and sound better.

I am sure it will take time to make the right adjustments, and the amp also needs burn in time. For now, it sounds very promising. I am going to listen this weekend with just the Adcom amp to see if it has "acquired" some "audiophile airs", but I am pretty sure I will get back to biamping with tubes for the voices. I will keep you informed if anybody is interested.....