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.
John (Hillig) is a great tech and a really good guy.  I've known him for many years.  He did a couple of Hafler and B&K amp upgrades for me back in the day.

Wonderful work and well worth the money back then.  Not sure what the charge is now for your amps, but there are many decent amps now on the market that may be better than putting more money into what you have?  Just sayin'.

If you do have John do the mods/upgrades, you won't be disappointed.
we sent many Hafler customers to him to wring out better performance, none were ever disappointed 
Rather than upgrading the existing design of the amplifier, Mr. Hillig specializes in a redesign of the amplifier. He chooses certain amplifiers as the "bones" on which he builds his own design.
He generally uses the transformer and portions of the power supply, pots and switches while most of the existing circuitry is replaced with his own circuit boards.
I have a couple pieces which he has redone; a Hafler DH-101 preamp and a DH-500 power amp which are significantly better sounding than the originals. I am also currently using a Musical Design D-140 which is his own brand.

I highly recommend his work.   

The  mods that he advertises on his web sight for Adcom GFA 555 are LX,  LX elite, LX mini- Platinum Upgrade, & under "amp options" filter capacitor replacements. Are you telling me that Mr. Hillig offers different options besides these?

It appears that new driver boards are limited to the Hafler Power amps at this time, but I think they were once available for the Adcom power amps also.

He does do upgrades using his MC-3 circuit board on certain Adcom preamps as well as outboard power supplies, though.

I have a Musical Concepts modified Adcom 555 John did for me back in 1989. After reading the review in Absolute Sound ( Volume 13,Issue 55,1998)by Frank Kaplan I pulled the trigger and sent it in for mods. Unlike the one in the review I had mine turned into Dual Mono with Dupont Teflon caps and the Platium mods plus Edison Price copper binding posts. It came back sounding like a warm tube amp,gone was the edgy highs and the bass was tighter and more controlled. This amp has driven Vandersteen Signature 3's,Infinity RS3B's and Odyssey Lorelei's with no problem. I still have it and pull it out every once in a while and fire it up. I used it with the Adcom 750 pre amp that Musical Concepts modified to platinum level and it sounds very open,extended an imaging is dead on. 
I doubt you would be disappointed in the money spent vs. results.
Yes I moved on to a pair of Plinius 100's mark 3 in mono mode but the Adcom has a sweet spot in my heart even today.

Realizing that my Adcom 555's are nearing 30 years old, I was just looking at having the capacitors replaced. After doing research
 on line I found a few really good techs out there that will modify  older amps. Musical concepts looks like one of the best. Thanks for your review.
Something to ponder,if you send them to John ask if he can put a I.C.E.on them so you can use power chords of your choice. Good Luck.
@tomcheeser...I saw your other thread about Big Sky Audio.  I've never heard of those guys.

If you really are going to have this done, please let John do it.  He's been doing these mods forever and probably knows more about them than anyone, (just my .02 cents worth).

I have a brand new musical design D140 amp its the best  money Iv spent in my 40 plus years in my hifi journey! That’s all I have to say period!

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.