Best tube pre-amp below US $ 10.000,00 ?

Frankpiet, there are big differences between the CAT SL1 Ultimate and the Hovland...on your fine speakers you would hear them immediately.

Since your amp has balanced inputs you might also consider a preamp fully balanced throughout, and there are very good choices within your budget.

Brian

Franpiet
I dunno. The only way to determine that is to audition each of them in your system. Hearing them side by side by side at a dealer would be helpful provided the amplification and speakers were similiar (ideally identical) to your own. However the chance that any retailer has both Hovland and CAT is small although you may find one in larger metropolitan areas. Supratek does not do retail so a 3 way comparison is quite unlikely.
Performance vs. $$$ I think Supratek is untouchable as you are saving 40%-50% buying owner direct. All of course IMO.
FYI, I have the Grange not the Cortese.

A used CJ ART II.

I would say a new Blue Circle BC3000 mk2.

Read some of the reviews, I think you might like to give it a try.

www.bluecircle.com

Another option would be a CAT pre-amp.

Happy Listening,
Nick

CJ 16LSII
Thor 1000
Wright Sound - anyone of them for the money