Step-up from Plinius SA-102?

Consider a pair of bridged BEL 1001's.
These amps are tough to acquire but have a cult following.
I've heard the Plinius 102's transform to another level when bridged. Why not try this approach first?

The SA102 tends to lack bite, and it sounds like that might be why you are hankering for a change. I was in a similar position a few months ago except I was reducing the sheer size of my second system (keeping my lovely wife happy) and replaced the SA102 with a Perreaux Radiance integrated. The music definitely became more engaging, but it did lose some of that muscularity and emphasis on inner textures that the Plinius had. My point is that I doubt that you could say the Radiance was 'better', but I ended up with a more musically engaging system and I am pleased I made the change. If I am right that the music has become a little bland for you, then the issue is probably less about what is better than the Plinius, but simply that the Plinius sound is not what gets your system boogying. There will be many amps that you could look at that will overcome the problem you are having with the Plinius.

It's rare to find Plinius amps not providing enough power, especially the SA-250. In fact, I'm wondering if the amp is really the problem. You must be pressurizing an awfully big room. Maybe you should double check your power situation (also don't run the amps through a current limiting power conditioner.) I guess speaker cables/power cables could also be investigated too for excessive length, proper gauge and/or incompatibility with the amp.

You also may want to "back door" the problem by trying a preamp with a little more gain than your Classe. It's common to overlook the preamp, but a preamp can affect every area rather significantly.

Nevertheless, if it is the amps, you got a handful of good suggestions. I don't think you could go wrong with the super powered Edge, Halcro and Boulder models. On the less expensive side, the Parasound JC1 and McCormack DNA500 may work well for you. However, when you need that much power, considerations such as size, cost and heat frequently become an issue. If so, you may want to try a high powered digital amp (like Spectron) to alleviate those issues. If you like the sound, you could even get 2 of them and still save money.

The problem I had with the sa102 was not a lack of power, but sounds like what Inpieces was complaining of. Essentially the sa102 can sound a little lifeless and lacking drive in some (repeat some) systems, despite its considerable power reserves.