digitech rds & pds triggering solutions? | midi to cv converters?

[adam <submersible@worldnet.att.net>]

hello loopers

posted this a few days ago and didn't any feedback or advice. maybe this
pre-midi triggering question  is for the old timers on the list...

I have an alesis SR-16 midi drum machine which I would like to use to sync
up the following. I'm looping guitar feedback and ambient reverb washes
through them....

(3) Digitech RDS 8000 delay/samplers
(2) Digitech RDS 7.6 delay/samplers
(1) Digitech PDS 8000 delay/sampler

The alesis sr-16 will not produce a +5 pulse. from what i understand the 
RDS
devices require a +5 volt input to trigger/sync to other pre-midi devices.
is there a" midi to a +5 volt pulse" converter that can read midi info from
my Alesis SR-16 and output a pusle? Let me know if you know of any
product/products that can tackle these duties. I'm love to have 6-8 
triggers
for expansion and flexibilty. For my live thing I would like some devices
triggered at an 16 count, some at 8 counts, and some at 4 count.

I'm also curious to know what the rest of you are using to trigger these
older RDS/PDS devices with? any suggestions? pitfalls? triumphs?

thanks

adam