OK, in This Thread I bought a Crown PS-400.

I added a APT Holman preamp and am happy with this set up, except it can be driven to clipping pretty easily into a set of 250ti.

I see that the Crown is rated for 4 ohm service. I ran it hard for an hour into the 250ti and it wasn't even warm. I have a set of L220A that I have set to play nice with the 250ti, so I hooked them all up.

Now I get some really nice sound levels, no clipping, and effortless jamming. I played almost 2 hours before I put any Steely Dan in

Any trouble with extended 4 ohm operation (and I'm just guessing on the 4 ohm...whatever a set of 250ti and L220A a side has)?

Sounds great, very minimal heat, no clipping lights, quite a bit more volume than just the 250ti. And I can always unplug the L220A if I want to just listen to the 250ti (this is an awesome combo with them alone).

Now and then I see somebody list a "reference track" or something to gauge your system against. Look for a CD titled "Thunder" by S.M.V. and play track 3. That'll clear your sinuses, the snow off your roof, the cobwebs from your speakers. If things ain't tight, you'll know it right off.