Coupling Capacitor upgrade? Which one first?

Dac is altmann attraction dac with 3.3uf wima mks2 63vdc output coupling caps. Amplifier is a diy chip integrated amplifier with 4.7uf wima mks2 63vdc  input caps.
Both working with 12v.Using 35v plus will be enough I think. 
Source is linear psu powered esi juli xte sound card. Speakers fostex full range bass reflex.

I tried to change wima leads with non-magnetic leads. There was an improve ment.
I also tried to use beeswax filled electrolytic cap(it is a diy effort) for input of the amp.I started to get soundstage information and vocals had more clarity.
But electrolytic caps seems unstable performance for dc blocking. And I realized a good cap can be very good :)

Still I don’t understand why wima caps aren’t good enough. But I decided to try a good cap. But they are pretty expensive and probably all of their website has no information about their products.

Audiocap rt or theta ppt
Jantzen alumen z cap
Rike audio s cap 2
Jupiter condenser beeswax ht or wax ht
Lefson c-mod
Intertechnik audyn tri reference
Clarity Cap cmr
Audience auricap xo
Jantzen superior z cap
Mundorf supreme evo oil

These are all I listed from reading all over the internet.. :)

I really like Cornel Dubilier over Wima's.

Cheap, small. Worth trying.

RIFA 450 are inexpensive and better than Wima. But try 3.3uF and 4.7uF Jupiter Copper foil wax if you want the best.

Still I don’t understand why wima caps aren’t good enough.

They are, I would suggest save the money and look for a "direct coupled output" dac with TDA1541 or better still PCM1704 even 1702.

Cheers George 

Second thought, since you have a non polarized 63v cap on the input of the amp, just bypass the one on the dac (direct couple it) there’s no need for it, at least you get rid of one "pita" cap.
But make sure you power up the dac first then the amp.
And turn off amp first (wait) then turn off the dac.

Cheers George