I have a Denon 4800 receiver but use 3 Marantz 6100 monoblocks for my front stage. Can I control the power on and standby modes of these amplifiers with the pronto, since I don't have a Marantz receiver or pre/pro? Thanks for any suggestions

This may sound crazy but try using the marantz vcr power or vcr input on a marantz reciever.....
I don't remember which one it was but there was a glitch with a vcr related ir command that turned the monoblocks on and off.....
Give marantz tech support a call they should know....
Try those 2 code first...

I've been able to control a set of MA500s through the D-Bus jack using an RC2000 and a Nirvis Slink-E.

If you aren't familiar with the Slink-E you can search the boards here or take a look at www.nirvis.com

Using the Control-S port on the Slink-E you can send unmodulated (no carrier) RC5 Commands to the amps.

The downside is you need to have a computer hooked up to do the code translation, but you gain alot of flexibility that way. Plus if you've got Sony Mega CD changers its the best way to control them.