Want a new amp but what to get?

Here’s another excellent option that’s cheaper than the others I mentioned but will make your 948s sing. Like the Pass amp it’s also pure Class A. I’d just check to see how old it is just to see when/if it might need to be recapped.

https://www.audiogon.com/listings/lis9di3b-clayton-audio-s40-solid-state

If it were me, I'd buy a Valvet amp.  Read the reviews.  The E2 is probably a little too flea powered even for your speakers, but the A1.2 should work just fine and is well within your budget new. 

https://highend-electronics.com/products/valvet-bricks-a1-2-power-amplifier?variant=31868821635

Sounds like you may be looking for a little more heft or meat on the bones in the midrange? McCormack amps are known for having expressive mids for a solid state amp, and as an owner of a DNA 0.5 Rev A amp I’d agree with that. Here’s a nice DNA 1 with recent Gold Special revisions that would be a big step up over your Rotel and is priced at half your $5k budget.

https://www.audiogon.com/listings/lis9fehd-mccormack-dna-1-smc-gold-special-solid-state

There’s also a very clean Pass Labs XA30.8 available under your price cap that would give you rich and expressive mids and that Class-A smoothness and liquidity. As it’s a pure Class-A amp it will run on the hot side, which might be a concern if you like to leave your amp on all the time or don’t want the heat.

https://www.audiogon.com/listings/lis9f6j0-pass-labs-pass-labs-xa30-8-power-amplifier-solid-state

Both are excellent amps that will yield significant improvements in the mids and many other areas as well, and your speakers will definitely benefit from and reward you for the additional refinement and capabilities of either of these fine amps. Hope this helps, and best of luck.

You'll get better and more meaningful recommendations if you tell us what aspects of sound reproduction are most important to you and what you're looking to improve upon over your current amp.