All film PS caps in Crack and/or S.E.X. 2.1 ?

[Raksasa]

Here's a question for the technically knowledgable (carried over from Crack Output Cap U/G thread, at Grainger's request):

Is it possible to use Metallised Film caps (polyester or polypropylene) to completely replace polarised electroes in PS caps of an amp like the Crack and/or S.E.X. 2.1 ?
Any actual advantage to using either type of film cap ? Solen have 250 vdc 220uf caps (Crack).

Here's 2 CONs:  Size & cost.
Here's a possible PRO: Longer life (?).

Any other PROs ? Sonically ?

Not very practical, but I'm just interested to know.

Cheers,

John

[Grainger49]

I have PP Film caps in the power supplies of my Paramounts.  My FP 2 includes a pair of motor run caps (PIO).  The cost of film as well as the size as you already mentioned are the only drawbacks I know of.

Both the PP film and POI sound better, smother, cleaner, more detailed, than the stock electrolytics.

[Raksasa]

Wow, thanks Grainger.

Paul J said similar here: http://www.bottlehead.com/smf/index.php/topic,1723.msg21209.html#msg21209

Quoted for convenience:

Yes it is technically possible, and preferable. Film caps are more reliable and have much longer lives, as well as sounding better. Most popular on the forums are so-called "motor run" caps, but other types are available and as long as the ratings are suitable would work well. Because they are large and expensive, it is most economical to replace the resistors in the power supply filter with chokes. But the last cap in the power supply is effectively in series with the output cap, so it should be at least as big and preferably bigger, as well as being of similar quality.

I also see a few people upgrading their Cracks with chokes. I'll look into that also, as i don't really understand the advantages of that.

Anyone else have experience with going all out on replacing their PS caps with large Film or Motor Run caps ?

Cheers,

John