[Amps] Alpha 9500 questions

[Bob]

Thinking of acquiring a 9500. but first need to learn a few things. someone
help me with these questions? 

 

What are the "updates/upgrades have been done" that I often see along with a
"for sale" ad??   it seems to include (but not limited to): 

 

What is/are the xfmr/blower/hall effect upgrades made and why are/were they
done?  What do they fix/prevent?

 

What others besides the above are out there? 

 

When did they begin including these into production, at what serial
numbers/years? 

 

How important are they? 

 

How easily done are they ? 

 

Is the firmware archived somewhere to that it can be reproduced to replace a
controller if needed? 

The 87A I have seems to be crippled if this occurs, as I understand there
was no archive kept of the firmware and you can end up with a brick.
Apparently some of the devices used have limited write cycles as well and
are now beginning to crap out.

 

-bob, w9zv