Capacitor

The Theta caps are really not bad. Forget the Humble Audio Review site comments on these as in electronics they are pretty good really.
That said, your amps are top notch and upgrading to VH Audio Odams is something you will hear and appreciate post burn in. You won’t have to strain to hear how much better the amps will sound. If you buy 16 the cost is some $63 each. I would contact Chris of VH Audio and see if he would work with you on another 10-15% off? Never know. These will be better than the Jupiter copper. If you get the price closer to $50-$55 each, then the 16 will cost about $320 more for the entire amp upgrade. Money well spent if you want to hear the most from your amp and plan to keep it for a long time. 

If the discounted price on the Odam caps is still too high, then I would stick with what you have. Other caps priced at $20-$30 each would be a sideways move for the most part. On paper, I would think the Miflex copper cap an upgrade, but my ears and experience have not proved that out.

Some of this is subjective for sure. That is why I asked if you want a more forward and upper mids highlighted sound. If you do, then the Milflex caps may be for you. Also, the cap must fit in the given space. The Miflex are huge!

Dear @jasbirnandra  : 

https://forum.audiogon.com/discussions/best-harmless-signatureless-speakers-capacitors/post?postid=1...

Wonderland ( thank's Pauly. ) caps are designed and manufactured on purpose for : tone control. I'm not who is saying that but what exist in internet sites and that's why you are " happy " with and now willing to buy other 18 wonderland caps and of course your " technical leader " is whom support you as pauly too.

Here a second fact coming from different source white papers where not only you but all the wonderland  caps users can confirm the other link. Please read all the pages an carefully the pages 4-5-6 and you will know why the wonderland caps makes everything but function as a capacitor to fulfil the electronics needs ! ! ! :

https://www.wima.de/wp-content/uploads/media/WIMA-Audio.pdf


This is what your electronics needs. What you buy is different and your privilege, the amp can't " choose " other that what you want:


https://www.mouser.com/WIMA/Passive-Components/Capacitors/Film-Capacitors/FKP-1-Series/_/N-9x371?P=1...


https://www.wima.de/de/produkte/impulskondensatoren/fkp-1/


Look at the charts and ask Jupiter or Odam manufacturer that gives you that information.



R.

I consider the odam very reasonable cost cap, if sq as good as grannyring says, incredible value. In the whole scheme of things $300-$400 not bad. Loudspeaker crossovers with their much large impedance values, and prices, makes electronic cap mods look relatively cheap. My next cap mod will be the odams for sure, likely next few weeks. Their relatively small size is also in their favor, I've faced big hassles in regard to size fitting past film cap mods.

@sns, 
Agree! That big Canary amplifier is expensive, highly regarded  and I'm sure sounds divine.  If 400.00 dollars worth of quality capacitors pushes it further then that's quite the bargain/value proposition. Improving what is already very good. 
Charles