I think the choice of amps has a lot to do with how these speakers sound. Powerful ss amps wouldn’t be my first choice with 40.2’s. Like many BBC designs, they sound a lot better with low to mid powered tube amps.
However, if you don’t like them, that’s your prerogative... but I still think Marc should check them out.
As a guy who has 40.2s, has owned 30.1s, has had extensive listening time in my home with all the current Harbeths I can’t really agree Davey but as always this is really just about preferences so it’s all relative. I really like quite a few of the speakers you favour so this is just a divergence in what’s best for driving harbys.
I’d probably be more like Keith and fall asleep with 40.2s on low powered SET, and I have a 50 watt SET amp with iron soo big even Ked’s powerlifting girlfriend might struggle to bench press it... sure it plays the 40.2s and does many fab things but IME it’s just not the 40.2s at their best.
I love SET, and get the whole thing of how some low powered valves amps drive speakers well beyond the appearance of the numbers but for me this is more about matching characteristics of amps to speakers.
Most Harbeth owners I’ve ever read on the subject of amp matching (including Alan Shaw the designer of them who almost verges on amp agnostic) usually then recommend 50 watts minimum as a starting point for them. So while they are a reasonably easy 6 ohm they have just simply relatively low efficiency.
I’ve tried the 40.2s, 30.2 and SLH5+ with a range of valve and SS amps. With 24 watt 300B PSE monos it sounded rich and lush but just ran out of breath on bigger scale and definitely didn’t play rock convincingly the way they certainly can when hooked up to some larger push pull valve or SS amps.
In valves I’d go KT150 push pull, Jadis, Audio Research, Allnic, Octave etc and for SS just some really good larger current drive wide bandwidth types of amps with then a valve pre up front can be very nice.
They are a box speaker that has often been favourably compared to Quads in terms of their midrange and have a tone wood characteristic that for them to be making magic mids doesn’t really need any added euphonics to naturally sound rich... but they do really seem to benefit from some considerable headroom to sound effortless and that puts some welly and confidence into their style.
Of all the harbys the 40.2s have both the balance and the extension to do any music type justice (more so than the smaller harbys) and also really enjoy the kind of amps that are relatively neutral and wide bandwidth and effortless in power delivery with enough watts to get them properly going.
Their nature is lovely and kind to the music.
I love them and the 40.2s and 30.1s have similar natures but just a slightly different mix of strengths but I’m not even sure either would spring to mind as a suggestion for Marc given their possibly less than ideal matching with Marc’s preferred amps.
As an alternative I’d have thought maybe DeVore might be closer to the mark for Marc but then speakers are just such personal choices so who knows really, only Marc will be able to tell if and after he’s heard them.
I had DeVore 0/96s on loan for a month with the 845 300B tank like magic of a Line Magentic 24 watt 219ia and that was indeed a very lovely combo. Either speaker brand might potentially be of interest for Marc but who knows really? It’s just that he might possibly get the better out of Devores with his current system but with the 40.2s and his music preferences and particular amp choice that maybe he’ll get some very lush and lovely sounds but presenting the 40.2s just as a tad on sleepier side of their spectrum. They do grace easy but pairing them with an amp with more of a touch of robust grunge they can also be good for some proper prog rock soul.