Assumming you can bi-wire your speakers, you can try vertical, passive bi-amping with 2 Alephs and it should make a very noticable improvement. Part of this is because you have twice the power available (3 DB) but also, each amp will see the load from only one driver and that driver's half of the x-over and not the entire x-over. Also the impedance of the woofer half will tend to rise with increasing frequency and that of the tweeter will tend to rise with decreasing frequency. This will unload the amps somewhat from having to deliver as much current compared to looking into the entire x-over. Sound stage will get wider & deeper. The presentation will be more dynamic as well as more at ease. If you can get another Aleph 3, I highly recommend you try it. If you still run out of gas, try the Aleph 2.
One other consideration is the pre-amp. I say this because the Aleph 3 has a very low gain of only 20 DB. This means that you may actually be asking your preamp to supply some gain as well (in these days of digital & analog stages with high output voltages, most pre-amps are acting as attenuators). There is the possibility that you are stressing the pre-amp as well.
