Is there a cable that can warm up my sound?

I am not sure a cable will solve your problem, however you might consider this:

I recently purchased a wireworld Supernova III+ TOSLINK cable. It is a GLASS (not plastic) optical cable that you can get for $99 here at audiogon. Used to be that coaxial digital was considered better. However, this glass toslink is getting some pretty good reviews for being sweet. Search the recent archives.

Sell it all and buy a Sony SCD-1.

Try Cardas.

I recently added some Cardas XLRs to my system and I was surprised at the added detail and smoothed out sounds I got. I dont know which ones they are, they were hand me downs from my bro, but I can sure find out.

Although there are many possibilities, the Monster digital could be the culprit. What is the rest of your system comprised of? Also any recommendations that we could offer would depend on the degree of brightness you want to alleviate.

A reasonably priced digital IC I feel is smooth, open and throws a massive soundstage is the Acoustic Zen MC2. An overall excellent cable. Also, the analog IC from your DAC could be a factor, and for that I would recommend looking into Cardas Golden Cross. A very warm and full bodied cable with decent imaging and detail.

Is the DAC1 you're referring to the Bel Canto DAC1? If so, it's hard for me to imagine that unit being the cause of the brightness as that model had a reputation for being quite smooth.