Maxx VCF-6A EMS type Update

[tomg]

If the diff-pair lock up they could draw excessive current
and cook themselves. Not that this is likeley but it's a
possibility. 

It's a good idea to break the direct connection from the
emitters to the collector of the npn with a 1K-1.5K current 
limiting resistor. 

This is the way the Moog filter and original EMS are 
constructed. Shouldn't have a big affect on the cutoff and
could save a diff-pair+? .

Thanks to Dr. Steve Granger for pointing this out. The 6A 
page will be changed to reflect this update.

-tg