pass labs xa100.5 or pilinius sa 103

Hi there. I am about to say yes to a dealer who introduced the pass labs xa100.5
to replace my plinius sa 103 to drive my dynaudio confidence 4 with ear 868 w phono preamp and michell orbe sme v arm / ortofon a90 cart , shunyata v ray w kimber palladian power 20 amp power chord and au24e IC & speaker wire.

Anyone who has suggestions / experience to share is very highly appreciated.

That is tough, both have great sound and are built very well. You should see if you can try both before you buy. If all equal and you live in the US I would buy the Pass Labs service maybe a little easier. I have a Pass Labs X350.5 and my friend has a very similar sized Pilinius and both are excellent sounding amps and strange enough they both have a very similar sound signature.
Will the dealer not let you take the Pass home? I imagine the two would be close in performance and the sound a matter of preference without one being a clear winner.

my two cents...
"..pass labs xa100.5 to replace my plinius sa 103"

Why would you replace one amp with another, almost identical power capabilities and sonic signature?

Both are excelllent. I owned Plinius SA-102 but it did not have enough power for my speakers so I bought Spectron... this why I am puzzled...
Would miss the front switches of the Plinius, especially in the summer. Also has more gain so volume knob will be higher with the Pass.
Had pass x250.5 with contour s 3.4's. Also had plinius sa 102 ( extremely similar to sa103). To my ears pass/dynaudio far better. Plinius/dun combo had noticable coloration treble region which caused the soundstage to appear compressed. Did not like plinius at all. Pass sounded more like music. Also ran plinius on s 5.4 which are same tweeters as C 4. Got the same result. Could not stand it, but that's just me. Ymmv
This is easy. You already have the Plinius. Just borrow the Pass from the dealer and decided which sounds better in your system. I haven't heard the Plinius, but I did own the XA100.5. It is fantastic.
Spectron? One of my friends has $3900 Spectron and it is very powerful and sound decent but it ain't no high quality class A or AB amp and it for sure does not sound as good as my Pass Labs x350.5. It sounds impressive at first but when go back to the x350.5 you then understand what was missing on the Spectron.
Don't know about the Pass x350.5 but I would take Spectron (with the upgrades) over the XA100.5 (I own both), but again, it's subjective, all amps mentioned int his thread are very good.

If you want to compare Spectron with Pass Lab amp - and I love both (and I love Plinius too) but preferred Spectron - then compare them in "apple to apple" manner.

Pass Lab X350.5 or 200.5 or 100.5 cost much more then stock $3.9k Spectron. Compare Spectron stereo or better monoblocks or better monoblocks with upgardes until the prices will be more or less comprable. Howeveerr, still Spectron will be cheaper but its Spectron's business to price their product competitively not customer's. I wonder also what speaker you use and what type of music you prefer but its secondary to fair (more or less) equipment comparison.
I have the C4s as well..Pass without a doubt.Much better match than the Plinius,IMO.You may want to addresd new speaker cables as well