Absolutely perfect for valves as they are 93.5db efficient and an easy load to boot. Genuine 3 ways with 2 x 6 in bass 1 x 3 in Mid and a big 26mm? tweeter. These are quite interesting drivers made from some kind of compressed foam the tweeter is a plastic dome but has no quackyness! About a 3 feet tall 18 deep 8 wide. Nice finish to the woodwork. As for the sound. Well dynamics are us, fastest speakers I've ever had and beautifully detailed, no sibilance on vocals and very, very fast tight bass also have excellent seperation of all the elements in a mix, sound almost like big (good) headphones, I'm hearing stuff on my vinyl I never knew exisited! Have excellent imaging and set up a good wide deep soundstage. Work best close to a back wall and yet still image well. In fact why am I selling them!! These are very revealing and have to be driven by good electronics as they are very much a warts and all speaker - good valves I'd see being a fantastic match. Truth be told I prefer a more laid back sound than this which is highly engaging but not "warm" enough for my system, room and tastes I think the combo of Xerxes DV17 and these is just too much. So I'm aiming for something like LS3/5A's, Spendors or something and these will need to go to fund that. Fans of an upfront, engaging sound will have little to criticise here. Good reviews on the cabasse website look under MT420 reviews (all in french I'm afraid) retail was 1250.00 - £500 price is firm and will come with boxes instructions, black and cream grilles depending on what you prefer. Brass spikes with rounded ends on one side for wood floors. I'm 10 mins from Junc 3 M3 and wam prepared to demo to serious buyers.