What's wrong with my Cal Delta/Sigma?

Have you guys used any after market power cords? I am thinking about getting some PS audio mini lab cords for the dac and pre, since I heard the transport won't be affected by power cord upgrade.

JK, I am definitely getting some low noise tubes.

Ton, I am not familiar with tubes at all, but you think the large plates is responsible for your increased soundstage? I did some research, supposedly those tubes your using were custom made and somewhat rare. Also, being on a tight budget, I've been dwelling on taking a chance on cableplex powercords or the ps audio minilab cables since they seem to offer tremendous performance for the money, $199 for 10 awg, 3x shielded (boy, i am starting to sound like one of those absolutepower ads).

I reinstalled my stereo today. I gave it my best effort to separate the audio and power cables, I've cleaned all the contacts with an alcohol solution (eye make up remover has amazing amounts of alcohol presents, and many differnt types of alcohol too). I moved the transport/dac away from my power/pre amp. And, now, my system is free of everything it was plagued by. Thanks for all your help!
BTW, Monster reference2 is not a bad digital coax. Beats the hell out of the Monster datalink100 I was using.

I was using a marantz 63se. The tubes should be operational and well burned in because I purchased this trans/dac from a private seller who's been using it for years, and they sounded fine when I demoed them on his system.

jk, sounds like you spent a very worthwhile $100 upgrading your sigma? I will definitely look into that. I got most of my muddiness out of my system, but it still sounds kind of sharp, like a "tinny" sound. And there is more hiss coming out of my speakers than compared to when I am using other sources. Perhaps your suggestions can amerliorate these symptoms. Thanks

Dekay, funny you should mention about poor contacts between interconnects. I took out all my cables and reinstalled them like an hour before I checked your post. And I would say 90% of the muddiness has magically dissapeared. I just got two pairs of emeralds, used, from ebay, and perhaps these cables were suffereing from static electricity, as jk mentioned regarding his tubes and other equipment that suffered from being transported. I haven't used any cleaning solutions, which reminds me of those XLO cleaning cloths they used to sell. But, by reconnecting my cables, I probably shaken off whatever debris that was causing my system to not funtion properly.
Thanks for your help.