Preamp Output Capacitor: Mundorf Supreme vs. Supreme Silver Oil

This thread is extremely educational but at the risk of sounding a bit nerdy, I just want to say that these sort of “tweaks” should be handled with extreme care and sometimes best left to qualified techs and/or experienced DIY folks. Almost all these gears, especially the tube gears, run on some real serious voltages and the slightest mistake can have irreversible health and even life ending results. Capacitors in particular need to be handled with care for obvious reasons - they can hold charge for a while. 
Sorry, just wanted to throw that out there as I hate to see/hear anyone get hurt.

@billwojo Polypropylene caps do have a type of coloration that you may not notice until you "roll" other capacitor types into your equipment. The most natural sounding caps (IMHO) are caps that incorporate wax and/or oil. 

Insulation for bare wire can be purchased as Teflon or cotton tubing. I've used both and I agree that cotton does sound more natural only when I use it in moderation. There was a point that I used cotton tubing exclusively but music started sounding brittle after using too much. Now I alternate between both materials when I mod. 

@kalali I unplug the component before I work on it. That saves my life every time :p

@cal3713 I may revisit the Mundorf S/G/O for the tweeter network. Your assessment of it's imaging seems to match Tony Gee's. It may provide depth but is the stage wide or narrow as if you're looking down a pipe or tunnel? I really dislike imaging that crams everything in the middle. 

I'm glad to see that I'm not the only ODAM user here. I think that cap is special and posted my review here. 

I tried a dozen different polypropylene capacitors.
All of them have "plastic" coloration. 
In term of tone, smoothness and musicality paper is oil capacitors always bit polypropylene  capacitors.
I never tried Teflon capacitors.  Teflon isolated wire sound good but less natural compared cotton isolated wires.

Regards,
Alex.

I never tried Teflon capacitors. Teflon isolated wire sound good but less natural compared cotton isolated wires.

Teflon *insulated* wire has to be either silver or silver plated. Its more likely that the wire is the problem rather than the insulation.