Maybe Leaving SET for Solid State because I want bass

Sorry for taking this in another direction. But why not just add a subwoofer? You get the keep the swwe SET amp sound, also get a lot more bass. Think it will make the SET sound even better. 

On the note of speakers, like Klipsch, they are all short excersion woofers, they will never make the bass most people want. The bass is tight and accurate, with low distortion, but it will not shake the walls. If you get it to shake the walls, you can not be in the room.

I've had some very good solid state amps- Luxman 550 and 590, Coda, McIntosh, etc, and I keep gravitating back to tubes. Consider either a subs, or a pair of subs, or like someone above said, getting another amp for when the mood strikes to rattle out the mailman dentures with you bass.

What are the speakers you are using?

I don't know, but if you are new to the sport you might have to buy and sell or dmo to find the sound that best suits you. Many have "wasted" lots of time and money doing that! 

Good luck!

As Lamm's designer once said - I can get an incredible bass out of transistors but that's not how it sounds in reality.

If you like tube sound forget about ss,  just find a different tube amp, as Ralph and mulvelling suggested. Atma-Sphere and VAC would be a good idea to start with.

Subs are not a substitute for an appropriate amp for the main speakers. Do both of it if you are inclined to.

Your speakers are rated 60Hz -15,000Hz and 60 watts maximum.

Using tone controls to extend the LF response may damage the woofers in the long run if they are original from the 60's.

As mentioned consider adding a sub or subs.

DeKay