I was thinking of doing my own Penta's Mika and I'm glad you beat me to it, it seems like you've already saved me a lot of head scratching😁

I will definately watch this thread with interest. I think Dillen was working on an upgrade Cap kit for the Penta range although I don't know how far he has got with it. Hopefully he'll be able to drag himself away from his

As you've probably seen in the other topic I've replaced the caps by Audyn types.

The C1 27uF has to be made out of 1 22uF parallel with a 4,7uF one.

My suggestion is to replace all the caps on the boards.

Maybe you can order them here.

Mmm. I like the looks of the capacitors for the crossovers.

How much difference does audiophile caps like these do compared to normal (ie the ones I bought from you before this kit was ready 😕 )?

The audiophile caps will make a difference, otherwise there would
hardly be any point in mounting them, but the difference to
the reasonably new electrolytic caps in your Penta's would
be marginal compared to that of exchanging old ones.
There will be some difference though and you will notice it, I'm sure.

The lifespan, however, will be greatly improved in that the
foil caps will last practically forever. No electrolytic caps will.

Martin

 Here is everything you need to know about fixing our Penta´s,  step by step, with tips and links

Penta High End! A project

And finally, here is the finished product. I didn't replace C4 on board 14 (2,2u) since I had to use the replacements on the RL60.2's yesterday. There are plastic caps originally anyway, so I don't think MKT caps would make much of a difference. The huge 68u caps indeed make it necessary to cut a little plastic from the speaker bottom plates to make room for C3 on board 15 (upper right on pics).

It's getting late for decent listening tests, but I don't think the improvement is as dramatic as it was on the RLs. It's definitely there, though, but the number of expensive caps makes the price/improvement ratio worse on the Pentas 🙂