Musical Concepts amplifier modifications upgrades

I would like to hear from people that have had their amplifiers modified by Musical Concepts. I am looking at having two GFA- 555 amplifiers modified / upgraded by them. I only want to hear from people that have had their amps. upgraded by Musical Concepts.
I have an Adcom GFP 565 that was modded by MC - elite mod and a Hafler XL 280 with PA7 Elite mods including TP 202 and 220M. The sound is fantastic. Worth every penny.

I have a Hafler DH500 that John installed all the mods in including dual stacked power transformers. Also have his Hafler DH110 with all the mods. A friend has the Musical Design DAC 1 hooked to electrostatic. Amazing sound quality. John is highly recommended.



I too have had John Hillig modify my Adcom GFA555 back in the late 80's. John does some great sounding mods. Since then there is a new kid on the block so to speak. His name is Chris Hoppe of Hoppe's Brain. I have never in my life seen anyone who is more knowledgable when it comes to Adcom amplfication. His work restoring, Adcom amplfiers has to be seen to be believed. He takes every amp completely apart and dips it in a cleaning solution, has his own brand new input PC boards that he installs, along with new PS boards, caps.....ect. He uses some of the finest parts available. From Vishay, IXYS, On-Semi.......ect. He even sells these as kits for those so inclined. Check him out online under (Hoppe's Brain)