The best coupling caps in power amp ?? Mundorf, Infinicap ??

The difference between Duelund CAST and Jupiter copper is this. I have used both in crossovers, tube amps, preamps, hybrid amps and dacs so I think I have had good experience with them both. You must let them break in for at least 150 hours to know how they really sound. This is a must. 

The CAST caps are a tad more tipped up in the upper mids. Some may like this as it sounds very resolving and open. For me this slightly tipped up upper mids caused my tinnitus to flare up. It was a tad too aggressive for me. I found this tendency when used in electronics, not in passive speaker crossovers. In crossovers they are magic. The Juputer caps have more top end air, improved Micro details, and an obvious improvement in bass impact. The Jupiter caps are far less expensive to boot. They seem to work better for coupling and output in tube amps and dacs. 

I have had  less experience with Vcaps, but one the one occasion I tried them they did not offer the "meat in the bones" weight and tone of the CAST or Jupiter caps. Crazy resolving however. 

Duelund’s Cast-PIO-Cu caps ARE more resolving and open, than any that I’ve tried over the years. I don’t want to hear anything but the original music and venue, without any editorializing. Duelunds are just less, "there" and allow me to hear further into whatever’s on my recording. I’ve had four in my Cary SLM-100 monoblocks, for a few years. btw: Some say that foil orientation doesn’t matter with stacked caps. Testing for noise proves otherwise.

I too just replaced the coupling caps in my 300b Audion with the Jupiter Copper caps and the results were excellent. Very Surprising the improvement.

Rodman,
It's interesting to note that when proponents of the VCap describe its character the word is neutral. 
Duelund CAST proponents descriptive word is natural.  Both are meant to be complimentary yet they convey perceptive differences. Having used both capacitors I understand the chosen terms. Natural is the highest compliment I can use to describe an audio product. 
Charles 

I have built more tube amps that most people have seen.......I have used 20-30 different caps over the years......I have always been interested in the descriptions people give of there sound experience when dealing with different sounds , speakers and delivery of sounds.......I try and use this information in the construction and delivery of tube amplifiers.....I try to understand the descriptions people give for different sound quality in words that differ from one to another when describing the same sound ......When one person says "warm" and they are using a V-cap another may use a totally different word to describe their experience ......autospec