Old Amp vs. New Amp

Audio gear is like everything else. It has a flavor that reflects the era in which it was made. So it's not necessarily better, just different. Like a digital photograph nowadays is clearer, has more resolution etc, than film, but it has a different feeling. I think probably many people - including myself - gravitate towards something that reminds them of early experiences with music.

I have been using a pair of Bryston 3Bs from the late 90s...they work great.

If they don't measure any better, then they aren't.

I use Outlaw Audio M200 monoblocks in my five channel system, driving Thiel 3.5's and 2 2's.  These are Class A/AB at lower power levels and switch to Class D above 85watts on up to 200wpc (8 ohm)  or 300wpc (4 ohm).  Their current model is the M2200, the same amp but with an added pair of balanced inputs.  These sell online at <$400 and can be returned if dissatisfied.  They have high bass control, excellent transparency, and a coherent and wide soundstage.  A good option to explore.

There are a ton of older products that are much better sounding than some of the newer items made today. When I say better, I mean in every way including transparency and openness too.