Integrated for bi-amping with AtmaSphere MA1s


My speakers (Ascendo ZF3s) have separate terminales for each driver.  I am currently using Atmasphere MA1s for the mids and tweets, and using a Pass X1 and Aleph3 for the woofers.  I'm also using a set of old Entec LF20 subwoofers crossed over with a Behringer Ultracurve pro for the really low frequencies.  I would like to replace the X1 and Aleph3 with a more powerful integrated, and am not sure what to use.  I've been away from this hobby for a number of years, but my first instinct when I think low frequencies is Krell.  The S300i looks intriguing, but I've read that it comes from a dark time in Krell's history, and may not be terribly reliable, and not up to the stnadards of low-frequency reproduction Krell is known for. 
Is this a good choice?  What else should I consider?
honest1
What about a good class d? There are a few good ones with tons of power and NO NOISE background.. I love um. Run cool...

What's wrong with the Aleph3? That is a good amp, too. Quite a little heater though...

It will push any load, down to  0 (zero) I think. :-)

Regards
The Aleph 3 is an awesome amp! I’m just thinking it might not have enough power for the woofers, although it does sound pretty good. I’m hoping to get a bit more dynamic transient response with a bigger amp. I thought it threw a lot of heat until I got the Atmaspheres.
I would consider class D, but I don't really know what's out there.  I'd also like it to have a volume control and a preamp out to feed the subwoofer. 
rouge audio cronus magnum has preamp outputs for biamping and 2 outputs for subwoofers it is tubes 
I like a few different ones, depends on the duty. For bottom to top, Hypex modules, work real well. Mine are from Nord, in the UK, and got wonderful service. There is an option for volume control, rack mount, buffer board, opAmp options. There is a company called VTV on eBay, they have Hypex modules also, state side.

Your running a 2496, Behringer? That will give you 6 lines out with any signal you want for subs or otherwise.
I use them for all my, bass management including servo bass, MB / Bass columns, and standard low rider bass bins (under 36" tall). I use Behringer 12Ks for all my bass work. 450-550 for 4.5K per channel, and bullet proof. They are good to 2 ohm or less.  I think I paid 1400.00 for 3 new amps wit h3 year warr.
Full DSP, on the fly correction, for 6 channels.  2496/12k x 3. I’m a Mac guy so I have tone control to boot.

I mod them and disconnect 2 of the three fans, and put one on a toggle switch. They work perfect and have volume control, LP/HP filter, mono/stereo output. Did I mention 4.5K at 2 ohms and 3K plus at 4 ohms. LOL NO NOISE! Dead quiet, on the floor noise.

Second, my little toggle switch addition, makes for late night, low volume listening, with a flip of a switch, no fan noise, I’ve seldom gotten them warm without the fan, much less with, and with THREE, you’d be DEAF, if they ever got warm, they can really pump it out...VERY low distortion.

Regards