Recommendation for Class-A integrated amp

Of those choices I'd lean towards the Pass or Luxman.  The Sugden would be a better fit with higher impedance speakers that aren't 25W minimum like yours.  Your Ascends drop to 4 ohms and I'd think the Pass and Luxman would cooperate very well with that.

I do lean more towards either Pass or Luxman at the moment, but also curious if there are more choices available I should be considering.

We used to sell luxman and their gear was excellent however we found the coda csib to sound even better

The coda csib is a unique integrated which is exactly the same 6300 .8 amplifier with a Coda preamp board

https://hometheaterreview.com/coda-technologies-continuum-no-8-stereo-amplifier/

The csib offers 18watts of pure class aand 160 watts class ab

You can send the amp back for rebiasing and get 250 watts class ab with 12 watts class A

You can also go to the 400 watt class ab with 8 watts class A

So you have a very flexible integrated amplifier based on the highly regarded Coda.8 amplifier

The coda throws a huge soundstage is tonally neutral has great bass and excellent clarity

Dave and Troy
AUDIO INTELLECT nj
CODA DEALERS

The Luxman gives much more flexibility with Bass and Treble controls.  I would take the Luxman, hands down.

The Sugden Signature A21se is an awesome amp. It lacks the bells and whistles of the others, but sounds heavenly. Besides, it is the original class A solid state amp, the one that started it all back in 1967. At $3250, it’s a bargain. 30 watts into 8 ohms/40 watts into 4 ohms, plus a larger power supply. If you can’t forgo the pretty VU meters, then buy a seperate VU meter such as the One little bear & Douk Audio, model vu1, off of eBay. It’s a great little VU meter for 50 bucks....you don't even have to wire it in, as it has a built in microphone, pretty neat.