Squezzebox does not qualify as a proper transport. It is a piece of shit in terms of SQ. Let me qualify to say that going OR5 is definitely not worth it and totally unnecessary for said Metrum DACs. I like these DACs but these DACs are not resolving or capable enough. Any mid tier transport should be sufficient.

First, thank you all for your help.

So it seems I have some options: Octave and Gungnir. Can I add Wyrd to all of those? Willing to try.

Marv, if you could try your Marantz + Gungnir, that would definitely help.

Judging my favorites harshly, K340 and K501 are respectively zingy and bassless. I want to err on the side of smoothness to accommodate K340 (and HD800, HE560).

I don't know the Marantz CDP but quick glance around the web seems to show pretty overwhelmingly positive comments.  What amp are you using right now?  You may be able to roll tubes to get to where you want.

Right now, I'm using Darkvoice 336SE. I've rolled enough that I believe I'm taking advantage of most its full (stock) capability or at least getting sound that I like. I'm currently using RCA 6SN7 5692 / RCA 6AS7G 6443. The 5692 sounds powerful: Arthur Rubinstein sounds more like Vladimir Horowitz. It's an acceptable starter amp but I'm planning to upgrade.

That's what I thought, except Zerodfx seemed to be saying he uses CDP + Wyrd/Gungnir. Maybe I misunderstood.

If I were you, I bought the new amp and only then I would evaluate the need of a new dac . In my experience, the sonett offers so much more control than my previous amp (Antique sound Labs MG Head... old but very good) . I've always struggled with some treble harshness with the MG Head even with warmest tubes. The Sonett offered as much treble as my old amp but with better quality so Harshness has gone.  Consequently, I feel that I can now use more neutral and resolving DACS  than before. I'm not affirmative. it's only my current impressions.

Hope that makes sense.

I get the idea. Thank you for mentioning it. I'd be inclined to go along, but I'd like others to chime in on it because I haven't tried enough better tube amps.

So the question is for the purpose of taming the CDP treble, what should I buy first: a DAC or a better tube amp ($1-2K)? What do y'all think?

Thanks for all your help. It got me this far into the topic. If now is not a good time for you, please just weigh in whenever you get around to it.

I renamed the thread given change of focus:

If I go with a DAC, I'm looking at Octave, Gungnir, or Caiman.

If I go with an amp, I don't know. Sonett 2? Used Super 7? Not sure what else.

(Whichever I don't get now, I can budget for after Christmas.)