Doepfer

hello
i recently recieved my first batch of modules and i'm having a blast 
with them!  anxiously looking forward to more...
i have two questions i'd appreciate some help with if anyone can spare 
the time.  
first of all, i'm having some trouble setting the re-trigger function 
to "on" in my a190.  (it looks like someone else has been looking for 
help in this area recently as well).  i've tried sending program change 
6 from pro tools and from a master keyboard as the manual describes, 
but no luck.
my other question is about the a130.  i'm using it at the end of my 
chain of modules, sending the audio out to my studio mixer.  i've 
noticed there seems to be a lot of "hum."  even when the gain is down.  
any ideas what it could be, or are they just particularily noisy 
modules?  
thanks!
sm