How can I start to change the system?

First of all, I must to say that I don't speak English well. So please keep that in mind. I live in Lima, Peru.

I have the following:

DVD player Rotel RDV 995 (working like an audio transport)
One Coral Cable interconnect (working like a digital cable)
DAC California Audio Labs Sigma II
AudioQuest Jaguar Interconnect
Integrated Amp Rotel RA01
AudioQuest CV6 Speaker Cables
Triangle Comette 202 Speakers

I enjoy this system a lot but I would like improve it. I was thinking about buying an tube amplifier and I wonder if I must buy another component before.

Any opinion?
Just click under Lak's system. Check out the filters and power panel. A picture is worth a thousand words. Besides, Larry is the world's expert on power outlets.
Wow LAK, have you written up any info on your isolation system? I'm REALLY curious about it!!!
Between Sean, Psychicanimal, others, and myself there's been a lot written over the years!