tube advice 5687s

Any recommendation on 5687 tube for a RSA B52 Preamp/Headphone amp? (These are the tubes that drive the headphones in this amp.) I am looking for softer, less prominent, less forward sound in the lower treble/upper midrange. I now use TungSol/Raytheons, which are nice,
but my headphones work better with with anything that reduces glare.

(I have found that Telefunken 12AU7s are the tube of choice for the
gain-tubes in the B52; they hold back a little but let you see into the space.)
There doesn't seem to be a lot of choices among 5687 tubes,
from what I can see. Thank you in advance for any advice.
I'm not a tube expert, but I think a Bendix 6900 is a 5687 substitute. Hopefully, the tube experts here will chime in.
Thanks Racamuti--I will look into it.
Bendix Red Bank 6900 is probably the holy grail of the 5687 tube type. However a LOT of people know this. IF you can find a NOS pair expect to pay upwards of $600 for a pair. Due to rarity and cost I've never owned 6900's so I can't comment on the sound. The old black plate Tung Sols are getting expensive too these days. For the money, I really like the GE "five star" 5687's. They are a fine sounding tube and are still below the radar, so prices are sane. As far as "glare" goes that could be caused by anying in the chain. Its not always the tube.
You can also use the 7044 tubes. the GE are cheap and sound good. (But not as good as the Bendix)
OK, thanks. I didn't think my current 5687s (tungsol/raytheons, not sure if they are "black-plates") are causing glare, I just
thought there might be a version with a mellow character.
And since those Bendix ones are so rare and expensive and I need 2 matched pairs, I don't think that is practical. But thanks for the suggestions.
Thanks for the advice everyone.