Is there a cable that can warm up my sound?

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.

I would agree Cardas has a nice analog like sound and may be worth a try.

You should try JPS Labs digital IC's. In my system it was very warm with excellent bass.

I will bet you money that the brightness is your speakers. That combo is not bright and a new digital cable is not the answer, either. Nor is a new power cord. You are working from the wrong side of the fence, old buddy.

Charlie

Charlie, my speakers are B&W, DM602 monitors and to be honest, I can't say they have been the tops in warmth. I am thinking that the upgrade of DAC might have brought the brightest to a new high.