Modding Hafler Amps?


Hi all. I've been away from the boards here for about a year, but I've got the audio bug...again.

The power switch on my Hafler DH-500 broke last month, giving me the lame excuse I needed to fork out the bucks to have it modded. An internet search found not only John Hillig (Musical Concepts), who I already knew about, but also Van Alstine. Has anyone compared the mods to recommend which company I should use to mod the amp? I'm not looking for all the exotic stuff- I just want the most bang for my buck.

Then the next problem: I also have a McCormack .5 amp (Rev A) that I love with my McCormack RLD-1. I could do a number of things - bi amp using both amps (Hafler for bass and McCormack for mid/high), toss the .5 (which I'd hate to do) and use either the Hafler by itself or purchase another used Hafler 500 and have it modded as well for biamping.

I can't really assess power needs right now, as I won't upgrade to speakers that really need the Hafler's power for another year, and I have no idea what speakers I'll buy. I'm thinking if I have more power than I need, no problem. Some day I'll probably want/need all that power, even if not in the near future.

Sorry this is so long, but thanks in advance for your advice!

aggielaw
I had John Hillig mod my DH-500, did the dual mono upgrade and signature level mods plus a few other tweaks. It was a pricey leap in the dark, based on stuff I read on this forum and elsewhere online. I have to say I am very impressed and very happy with the sound. I have listened to the same CD on some really pricey systems (McIntosh, Krell, etc.) and to my ear my system sounds a good or better. Huge sound stage and depth, a really "live" sound, great bass and clarity, very musical. Don't know about Van A, but to correct an earlier post I believe Hillig worked with Hafler, and his redesigned circuit boards are much more than a passive swap-out of parts. In any case, whether you go Van A or JH, you are buying the guy's ear... I only know JH's and I like it - a lot! That's my two cents.
If you're going to mod your DH-500 yourself, I highly recommend The POOGE Chronicles. They outline modding in general, and the DH-200 specifically, along with a number of other pieces. The principles they use could be applied to anything you were modding, and cover both the theory and the implementation. I bought my copy here:

http://www.audioxpress.com/bksprods/books/bkaa25.htm

Well worth the price.

David
Hi guys,
I am new to this site, but I wanted to comment on Hafler products modded by John Hillig at Musical Concepts in St Louis.
I am a "Golden Age" audio dinosar that goes way back to the Eicos, Pilots and Dynaco.I have had a lot of "hi end" stuff over the years such as Dynaco,GAS,ARC,Mac and I thought I have heard it all, until I purchased a Hafler 500 modded by John Hillig.I am hearing things that I have NEVER heard before and I didn't have to spend a fortune.The depth, width and detail of the soundstage is so much more than I expected.I am extremely impressed, especially considering the investment.Well worth it!

Yes, there are more exotic, and expensive amps out there that may sound better but look at what you have to pay.
I read somewhere that Hillig had been an engineer for the Hafler co. but not sure if it is true.