[SHXMD]

I elected to purchase a class A amplifier for Christmas-Pass Labs XA-25 to replace my 40 yo class AB Bryston 2B-LP.  (The rest of the chain is Auralic S1 Aries/LTA Tube Preamp to Amp by Inakustik Micro Air interconnects. Speaker wires are Iconoclast Stage II Silvers to Magnapan LRS+.)
My observation/question is when the streaming (Qobuz) the sound compared to local files (ripped on USB drive) with the Bryston the difference is clear but not so with the Pass lab. The Pass labs sound is clearly fuller, faster and maybe more engaging but the sound streaming sound vs ripped files are very, very similar. (Songs are the same and volume matched.) Thought I would query the experts here for thoughts and/or opinions about this observation and what the Class A amp may be doing.

Since I am new to the Amp I thought maybe over time I would able to distinguish between the two inputs but it is only in rare passages.

Thoughts are appreciated.

Thanks!

[Huskerbryce]

While I do not own either of these amplifiers I have heard Bryston amps and Pass amps.  In the same basic wattage class I tend to regard Bryston amps as having a little more edgy detail where the pass amps tend to sort of roll the details off a bit into a more musically soothing tonality.   Me personally, I like the pass amps as they don't fatigue my ears.  I could see where you may be hearing that edgy detail that pass amps turn into a warmer sonic character.

[FullRangeMan]

Any Nelson Pass power amp have great sound, even those that use multiple transistors.
Transistor Class A amps needs hi efficiency speakers as 100dB to sound best.
But now A and AB were both obsoleted by GaN-FET amps. IMO

[Early B.]

The differences between the two amps probably aren't the issue. We would need much more information about how you're streaming and ripping files, your settings, etc.