Upgrade from Spendor SP 1/2, what's next?

Personally, I never got what I desired out of my 1/2e speakers with moderately powered tube amps, even in a smallish room. IMO these speakers perform better with solid state amps, about 150 watts give or take to start.

Interesting - I went exactly the opposite. I had a Bel Canto S300 at 150 watts per channel and went to an Image 65i with 6550 outputs and 50 watts a channel. I'm very pleased with the current setup and have no urge to change out either amps or speakers.

As they say, horses for courses. ;-)

I am using SP 1/2 Es with a pair of REL Stadium subs, works very well. Use either MF M3 Nuvista [275 watts] or 4 Meridian 605 mono amps [300 total a side] to drive them. I would try a GOOD high powered transistor amp and see what I thought of the sound. I have several other speakers but these are the ones I spend the most time listening to. You are not going to get the same sound from another speaker, make sure you know what you are looking for before you switch.

I had the 3/5R's using 50 watt tube amps they have a big sound and placement is not an issue they are a sealed type which I always prefer to ported.Check them out I think you will like these very much.

I have been a Classic Spendor guy since 1980. I have also tried Harbeths, but preferred Spendor. You own one of the very greatest transducers ever made

Read this: http://www.regonaudio.com/SpendorSP12Loudspeakers.html

I have two suggestions. Buy a musical sub (e.g., ACI or REL). And try Speltz Anti-Cable speaker cable. They opened up my 1/2s and 100s -- utterly transforming the speakers from fantastic to mind-blowing. No joke. Been in the hobby for 35+ years and that cable is the single most significant upgrade I have ever made. Read the testimonials.

By the way, my Cary 300SEI (with 11 wpc) and the ACI sub are an intoxicating combo with the 1/2s. Put your wallet away, my friend. It ain't the speakers!

I've had Spendors for quite sometime. Great speakers, on the warm side of the spectrum.
Suggest you audition a pair of harbeth SHL5s- quite different frm the spendor line, more detailed and transparent but still has that beautiful midrange.
YMMV.