What's wrong with my Cal Delta/Sigma?

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.

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.

Hissing -- Most likely the tube needs replaced.

I used AudioQuest power cords with the Ferrite removed...

I have an Alpha/Delta combo, and I just replaced the tubes with 1963 GE large plates. This has opened up my soundstage immensly. Also, the analog cables and the powercord are custom made by a guy on ebay. Do a search for Cableplex. The Nirvana cables are the best I've heard, they beat out a pair of $400 straightwires, for only $75 per 1 meter pair. His powercords are top notch, both the alpha and the delta have one. As far as the digital cable, I contacted CAL, and they told me their perferred method is the digital coax. I have two that I perfer, one is the ZuCable Firemine and the other is a custom cableplex. I can hardly tell the difference between the two, but I perfer the ZuCable. The Cableplex Digital is only $20 and it is better in my HT than a $200 Tara Labs.

as far as cables, the Interconnects made the biggest difference, and the powercord on the DAC.

Yohjixme. I had the same problem when I hooked a Theta Pearl transport I got last week. Muddy, veiled and a fat midrange. Just like you, it turned out to be a poor mechanical connection. It all disappeared when I swapped digital cables around a couple times. And yes, Dekay gave me the same advice, which did the trick. Now I'm a very happy boy.