I got a response from Hadley 622 amp designer Jim Bongiorno,,,he will update my amp..I am psyched to say the least..
Here is the email back:
Dear Jack,
I was the last engineer in the design of the 622. I must be the only person in the world that knows this unit inside and out. Yes I would still do the upgrade if you desire. This would be quite extensive as the parts used in the original are quite antiquated by today's standards. It is a BIG job and takes many hours. One of the benefits however, is that there would be a dramatic increase in power output because the original output devices had tremendous losses. When I get done, the unit puts out close to 80 watts/channel which is double the original rating. I also strongly recommend adding the two servo cards (two are needed because the design is a full wave balanced bridge output. Also, the performance improvement is substantial.
The only drawback is the cost which is $600.00. This includes virtually all new semiconductors, caps, etc. Let me know what you want to do.
James
__________________
Here are some pics of the amp (nudies as well)
hadley 622 on the left
nudies:
