MIT's not good for tube components?

Let's put it this way: MIT makes a good neutral (ie accurate) cable with good (ie low) time smear properties. But that only applies to their upper models, not the ones you are using -- which are about the same as most mid-priced product from any of the major manufacturers. If you like the naturally warm tube sound but not overdone, the expensive MIRs would be an OK choice. For the same money as the upper model MITs though, you should consider either Purist or Transparent as having better performance in those same with quieter background -- especially the Purist products.

What your dealer said about MITs not being appropriate for a tube system is highly suspect, but might in fact apply to an acknowledged warm and fuzzy cable like Cardas.

Bottom line: Don't simply change your present cables for a similar mid-line model in another brand. That would be a waste of money. And if you're going to move up, consider the two other brands I mentioned, along with Straightwire, Madrigal, and Synergistic.

I agree with Jeff -- (MITs's hard-to-navigate website)
And I agree with John -- Purist makes amazing products. They won't "musch" a tube system, and they won't make a ss system sound like glass breaking!

Some of our great old standby manufacturers seem to have rested on their laurels for a long time now, without much in the way of design innovation/improvements. I'm talking about: Monster, MIT, Audioquest, Kimber, Straightwire, XLO, Magnan, and a few others I can't think of right now.

With Purist, even their bottom-of-the-line Musaeus outclasses the best of many of the aforementioned manufacturer's best offerings. Here's a case in point:

I have an all Purist (Venustas) system (even the phono cables and some Dominus power cords.) EXCEPT, I never did get around to replacing the ICs on my cassette deck (2 pair of Straightwire Maestro 2's) or on my tuner (MIT 330s)

I bought a used pair of Musaeus to use on my cassette deck as soon as I could find a second pair. In the meantime I thought I'd swap out the MIT 330s on my tuner. The tuner is an old Technics ST 9030, recently aligned and modded. Although it's a great tuner, I was disappointed in the only very small improvement after the mods. So you can imagine my surprise and delight when after installing the Purist Musaeus cable, the sound of the tuner improved several quantum leaps! Deep bass, great vocals, a real soundstage. It was just amazing, and as an unintended A-B comparison it really knocked my socks off!

The moral of the story: Always look for those manufacturers that are making real mechanical/electrical design innovations, and not just using fancier materials, etc. (Transfiguration cartridges, the new Martin Logan Summits are two other examples.) As for cables, right now, the ones that fall into that category (in descending order IMO) are Siltech and Purist, Transparent, Madrigal CZ Gel, Nordost. (I may have missed a couple.)

Unclejeff, if you go back to the Purist website and download the catalog in pdf format, it is quite detailed and shows everything they make including specs and construction diagrams.

I read that the problem with network cables and tube passive linestages is one of impedance mismatch with the tubes directly coupled to the IC. Not sure where I read this however.