Rock and roll indeed.
Caps tried:
Auricaps PP
great value, glimpse of hi end
Audionote PIO copper
Ouch expensive but very good
Black gates several ranges
needs too long to run in but good to very good
Solens PP and metalised PP
real value for money in speakers and digital circuits
PIO Dubuilier
when you can find them great in valve power supplies to settle those shocks
Sanyo Oscons
comes in different flavours, only low voltage
great for digital circuits
Tantalums-
Naim use these a lot - fast extended HF with 'bounce factor' USe top brands at high voltages
PIO GE -
PIO Soggy foil (?)
Wimas PP
good for DAC's
Motor run - pp, high voltage - bit bright but great vlaue for money
Ero pp -
used by some v good UK designers in valve gear
Philips PP
in high voltage ratings pretty good
Suflex polystryne
maybe the ultimate TDA1541 caps
Silmic 2 Elnas
OK for voltage supplies
Silmic 1 Elnas
OK for voltage supplies
Elna - (red body) electrolytic
musical through the mids
Panasonic - various
Reasonably priced for what they offer - power supplies
British Aerovox large electrolytics
Big power supply caps for transistor monsters
DNM slit film electrolytics
a step above all other electrolytics for transistor amps
Gosh, I could go on for ever here. There is a large difference in performance acording to where you use them. As Kajak suggested, its a balancing act to get the best from a design. Coupling caps or DC blockers are the best place to be able to hear the benefits of getting the right cap for the cuircut, power supplies are a fair bit tougher.
Having heard two Killer dac implementations with slightly different cap selections the 'focus' of sound is slightly different. SGR prefers the Duelands copper, our recent Dutch friend may appear to find the Audionote silver in oils better. A lot depends on implementation and it would appear the caps are not being compared in Oz and Holland for being in the same circuit so perhapts not the best results for those looking on. Both caps are expensive beyond the norm so a carefull appraisal of what circuit and at what operating paramaeters would be good for all to see. Generally the higher voltage rating of a cap results in a better sounding device in my experiance, your milage may vary.
Can some one else chime in here, this could be a very usefull resource. I have yet to try Jensen caps as these are supposed to be good to excellent .
rgds
V