Speaker Connectors: Banana Plug conversion adaptor to spades

 you could look at audioquest or cardas has them
 
could also do a google search  banana plugs to spades and there are other options on Amazon.

Actually, though not audiophile approved, I have found Monoprice connectors to fit my needs.  A number of them are gold plated, they are very inexpensive, so you can try them and if you don't like them you are only out a few bucks.  I also like their HDMI cables.

For $10 for each spade, Zu will re-terminate your cables and they'll look great. I had their speaker cables and went the other way, from spades to bananas. They'll even pay for the shipping back to you and the turn around time was one day. If you decide to go that route, just call them in advance to set it up. Great guys to deal with.

All the best,
Nonoise

I use these:
https://www.amazon.com/Cardas-Premium-Speaker-Adapter-Connectors/dp/B00SG3Z922/ref=sr_1_6?ie=UTF8&am...
They work well and fit snug on the banana.
Hopefully, they fit on your termination.
B

Black Cat Cable sells the XOX spade to banana adapter for that purpose. Thet sell two versions, the Reference and the Studio. Check them out.

I have a similar question, am curious if either of these adapters (both still available in Jan 2020) worked on the Thiel's.  It's mighty tight at the bottom where the connections are, one of my least favorite things about otherwise great speakers.

I actually learned that I was incorrect in thinking my Thiel's would only accept spades.  I had previously encountered speaker's whose mounting post knob had a plug in them that was easily removed.  What I discovered with my Thiels is I had to completely unscrew & remove the mounting post knob & punch the plug out through the bottom. 

So, I was wrong & I suspect that you have the same situation as I had.