My 6922 Tubes Are Too Bright!

I suggest u call Andy at Vintage Tube Services and speak to an expert.
  It sounds like Mullard may be what you need, he can tell you about the sonics of the 6922/E88CC Mullard vs. other brands. But premium tubes are not cheap.

I’m wondering if the problem is indeed your CDP and tube selection. With regard to your Amperex, there are many variants and levels of that brand leading up to the PQ. The higher you go, the more refined the top-end.

I have also rolled quite a few NOS 6922/7308/6DJ8 in my DAC. I did not find them bright, but found differences in the bass slam and sweetness of the mids.
    Siemens and Telefunken are tubes that have open, dynamic sonics. Their top-end is extended but smooth, never bright. I would not use many of the new production tubes as a reference since few of them present linear sonics. Possibly try the
JJ/Tesla E88CC recommended by @newbee .

Can you tell us what the rest of your system consists of? Room size, any acoustic treatments?
It may be this CDP does not have the right synergy with one of your components, such as speakers, ICs, or preamp.

Amperex bugle boy 6DJ8--nos.

Yes, but which one? A fairly accurate review...
https://www.audioasylum.com/scripts/d.pl?audio/faq/joes-tubes.html#6DJ8-2

I’ve tried about 5 variants; they’re very different. Currently using
7308 Amperex PQ (ultra premium 6DJ8/6922) Holland....
same as Philips SQ Special Quality type.
Also have tried the 7308 Amperex PQ (Super Premium 6DJ8) USA.

The Amperex white labels (produced before Bugle Boys) have sweeter mids and smoother highs.