Expensive Tube Amplifiers

Yes both are film, but the Mundorf has a particular sound that is quite different from the Hovland or other vintage coupling caps that one might consider such as chocolate drops.  However designed, I consider the Hovlands vintage, not modern, because they are long out of production and one cannot just order them from a parts supplier.  For speaker crossovers there are a number of old capacitors that sound really good in some speaker designs that are, technically speaking, defective (e.g., caps with very high measured DC leakage voltage, but they work fine in crossovers because DC leakage does not matter). I am not saying vintage parts are better than new, I am saying that the opposite is not universally true and that there are some really good old parts that are hard to beat in some applications.   

Vintage IS an imprecise term.  I am not disagreeing with the comment above that the Hovland MusiCap is the same type of capacitor as a Mundorf film cap, but the Hovland sounds much more like some quite old vintage caps that are vastly superior to the Mundorf in applications where that particular sound is sought.  This dealer/builder frequently uses such vintage capacitors and uses only vintage carbon composition resistors because of sonic consideration.  Some of his premium builds includes IRC resistors from the 1930's that are not easy to find.  Again, based on his customer's comments on the sound, modern parts may be substituted; like Audio Note coper or silver foil caps.    

My own amp is a relatively recent build, but, many of its parts date from 1940-1960.  The input and output transformers are probably from the early 1940's and some of the signal path resistors are quite old too.  Most of the capacitors are also very old paper-in-oil caps.  The modern parts are mostly in the power supply--new electrolytic caps, new power transformer, and new choke.  The parts choice was dictated by sound.  

These are world class tube amps:https://www.nataudio.com/products/vacuum-tube-power-amplifiers/magma-m-hps.html

Carbon composition resistors do have some value in certain applications especially where very wide bandwidth is desired. (Resistors have a bandwidth above which they can resonate and exhibit capacitance. Carbon Rs don’t resonate until very high frequencies way above audio.) But Carbon Rs also drift in value over time. So if the value is critical, I would not choose CC resistors.  I also (personal taste) do not think they are the end-all for transparency.  They are warm sounding (to me). Anyway, now we/I am exhibiting some "drift" in relation to the subject of this thread, whatever that is. Jim made a statement; he did not ask a question.

When I think of vintage coupling capacitors, I am thinking of paper foil in oil caps, some types of which are now banned because of PCBs, and rightly so. I have a bunch of vintage Sprague oil caps; IMO they are awful. There are modern oil caps too, made by Jansen (sp?).  I've used those. They are not the last word in transparency but worst of all, they fail suddenly under voltage, even when V is well below their stated rating  That happened to me twice, and I will never use them again. I would never think of Hovland capacitors as "vintage"; they are of modern construction and may even have been made by REL for Hovland. In fact, I doubt Hovland the company ever made capacitors. REL makes caps for other companies according to their customer’s spec, e.g., MIT.