Set amps ?

That Speaker is considered an easy load at 8 ohms with a dip to around 6.5 ohms in the lower midrange region. The sensitivity is only 83 db as measured by stereophile.SET amplifiers range in quality and performance as do all amplifier types.Given the very low sensitivity of 83db, the room size and your listening levels will matter a lot with the lower power range amp(limited volume and headroom) you`re considering.

The better SETs have robust power supplies and premium quality transformers(along with better parts,wiring etc.) as opposed to lower quality SET amps.
You `ll likely have much better sucess with a higher power SET,certainly more flexibility,The better built SETs can sound wonderful with the appropriate speaker match.
Regards,

Agree with Sebrof,
Straight forward and simple circuits that require fewer parts sound natural and very realistic,just more like what I hear at live venues. I respect other opinions that disagree,I`m going strictly on my actual listening experiences. Many complex, higher power amplifiers sound artificial and hifi to me(they are`nt convincing). We all hear differently I realize and there`s something available for all of us.Good SET gets it right for me but will not do it for others.

Maplegrovemusic,
I would say the reason why well implemented SET amplifiers sound so good is due to a simple circuit that retains much signal purity. This results in a very natural sound and purity of music.

In the current 6 Moons.com there is a review of the new Avantgarde XA preamp. The chief engineer explains the mandate was to make the circuit as simple as he possibly could.
It has only one gain stage,only one transistor per side,no coupling capacitor or DC servo unit(it is DC coupled instead).He made the signal path wiring ultra short.

What is interesting is the reviewer points out that the Soulution 720 preamp follows and is built on this very similar 'simple' concept. It`s a good read if you have the time.

Nelson Pass has ventured down the path for quite some time with his First Watt amplifiers.They have become simpler and ever better sounding over the years. His latest S.I.T. anplifiers are the most simple yet and are said to be the best sounding of all the First Watt designs.

There is much merit in the keep it simple concept and SET represent the epitomy of that idea.The principle is lower the number of parts used while increasing the quality of them.That works for me.
Regards,

As usual salient comments from Almarg. I would agree this Proac speaker is`nt a likely choice for 'lower' power SET amplifiers.However there are some SET models out there that will mate with this speaker superbly. Too bad that it`s usally difficult to get these various amps into your system and hear for your self. As Jburidan says the sound can be magical(with the right speaker).
Regards,

Maple,
Most here agree, if you decide to try a SET with your speakers you`ll need the higher power versions(with good transformers and beefy power supplies).