Can all amps drive a 4 ohm load?

Nothing will be damaged. If your objective is just to sample the planar sonic perspective, low volume is OK, and your amp will suffice. Just don't expect to evaluate the potential of the Maggies.

You will definitely lose bass performance from the Maggies with this amp.

Hi,

the Audio Aero Integrated selects the impedance of the speakers automatically. This is straigth from the manual:

• Connections

Connect the supplied power chord to mains plug (1) and then connect it to the mains supply.
Connect the interconnect cables to the RCA plugs at the rear. The sources are identified on the front and are in correspondance with the printing on the rear plate

(2). You can chose LINE 5 as unbalanced (U) and balanced (B) input with the small switch located between the inputs. A tape monitor output is available for recording

(3)Connect the speakers cables to the corresponding binding posts as referenced on the rear plate printing

(4)The impedance is automatically adapted to the speakers.

Hope this helps.

Josep

My pea-brained understanding of this matter is that, if your amp has tubes in it (I believe this one does?), that your amp will work harder to produce less wattage when connected to a "difficult" speaker load such as 4 ohms.
Solid state amps, on the other hand, will also have to work harder, but usually can provide more, not less, watts. With only 40 or 50 watts to work with, I think you'll want to find an efficient speaker, 89db or higher, with a simple 1st order crossover that won't slurp all your juice.

Cheers.

Cheers.

Tfkaudio....The tube amp will not work harder. In fact you need to use a lower tap on the transformer output just to have it work equally hard. This is like shifting to a lower gear in a car. You can go up a steeper hill, but you can't go as fast on the flat. The solid stare amp is more like a car with an engine that has a lot of torque, so you don't need to shift gears.