Hi slvrsrfr. I've had the WA-33 for about a year now, and am a huge fan. I don't just use it as a headphone amp. Often, I use the preamp outs direct to my power amps, and have skipped a separate preamp altogether.
For most of the last year, I used a Lampizator Golden Gate DAC, after owning/auditioning many other DACs. It was fantastic and expensive (although less expensive than the Meridian Ultra DAC you're looking at). Recently, very much against my better judgement, I made the jump to the (even more expensive) Lampizator Pacific. Alas, it was worth it! My system (including my headphones) sounds better than ever.
Bottom line, I'm sorry to say, is that you'll need to listen to some DACs. The fact that you're limiting yourself to headphones doesn't mean you won't be able to hear the difference.
For most of the last year, I used a Lampizator Golden Gate DAC, after owning/auditioning many other DACs. It was fantastic and expensive (although less expensive than the Meridian Ultra DAC you're looking at). Recently, very much against my better judgement, I made the jump to the (even more expensive) Lampizator Pacific. Alas, it was worth it! My system (including my headphones) sounds better than ever.
Bottom line, I'm sorry to say, is that you'll need to listen to some DACs. The fact that you're limiting yourself to headphones doesn't mean you won't be able to hear the difference.