Final verdict with amplifier

For the record, you can absolutely damage speakers before driving an amp into clipping, although a distorted amp will get 'em first. Most speakers will handle some quick and clean high powered transient peaks, but any high current amp of 100 watts or so driven at anywhere near peak level will fry all but the sturdiest drivers in a hurry...only pro audio speakers or a few extremely sturdy home speakers with gigantic voice coils and heat dissipation capability can handle serious juice, and that's just not necessary for home stuff.

After further thought, on reading the "it didn't harm my speakers" statement, there is a possibility a little harm could have been done, if you drove them past their design limits. When speakers voice coils get to warm, the varnish insulator breaks down. Also this can damage the copper coil wire itself too. This also could cause a short between the wires, but not easily noticeable, because they may still sound fine, if they're not totally shorted. Also, if done more often, that can further damage the voice coil causing an earlier than normal failure, that may never happen if they're not driven as hard. They can fail in the future with less power do to this. IOW, your taking a risk. Hopefully, no damage was done. Being easier on them should give them a longer life, so can can keep enjoying them.

You keep getting not very good amplifiers with tons of power, way more than your easy to drive speakers need and expect a big difference.

I disagree that preamps are more important than amps. I think they're both important. Although to what degree depends on the components and the rest of the system.

With your fairly easy to drive speakers, you should be looking for quality not power. I'd guess that a good but cheap integrated, perhaps even a lowly Trends T-amplifier, perhaps something from Virtue, a Virtue One would slay anything you've tried so far.

There is a Dayens Ampino asking $450 and a Sansui integrated asking $350 in Solid State Integrated Amplifiers right now. The latter you should ask regarding current restoration status, if the system has been re-capped etc. But both are likely to be clearly superior to your current system (and probably your friends too).

The amp is the heart of your system. No matter what you upgrade or change otherwise, you will always end up listening to your amp, again. I can't believe that Son of Ampzilla is still for sale in the classifieds, recently rebuilt by none other than Mike Bettinger. This amp is 30 years old and will go toe to toe with anything on the planet, current or otherwise