Modwright KWA 150

Ideally, you would want to make a decision on your speakers in conjunction with that of your amplification. I'd narrow down my speaker options to your top contender and then try different amplification to see if you can obtain the sound qualities you are looking for. Though I have not heard them all, the speaker choices you have listed are quite different sounding. Picking an amp without knowing which speaker you will likely pair it with may not get you where you want to go.

Would you say vocals are very natural sounding or do they come through with some colouration?

I'd say vocals sound natural. Period. Like a person in the room. I would not call it colored, no. It is not warm or glowing...it's just very real/natural sounding (this also assumes an excellent vocal recording). So no, not tube-like, but it somehow seems to give a nod in that direction. It definitely does not sound like a typical classic SS amp like a Krell or Levinson (though they both have made quite a wide range of amps so I am stereotyping - pun really wasn't intended there). The KWA150 does a very good job of getting out of the way. Disclaimers apply.

Add Daedalus to your short list of speakers if you are considering a KWA150 - That pairing is absolutely wonderful. I have no interest at all in Daedalus, nor do I own a pair. I have heard the pairing extensively at Dan's place, both the Ulyses and the DA-RMa. If you have the space and budget the Ulysses is killer - if your space is smaller the DA-RMa gives you the same magic in a smaller package and with less low end grunt (which is prodigious with the Ulysses). I'd certainly also highly recommend AudioMachina, which I do own, but they're at a much higher pricepoint. Great synergy with the KWA. I do some work for Karl, so disclaimer there.

I live in a small market outside North America, but I have tried the physics and focus HD extensively and can happily live with either.

Daedulus not available in my market

Given what I have read on Modwright it looks like it would work well on most speakers?

Although I just spoke to the dealer, seemed to suggest it would sound better on a very clear open speaker than a speaker with a dark character.

So probably a good fit on the Marten or Focus HD or Audio Physics.

Forgot to mention I tried the Simaudio i-5 a few months ago, very natural vocals but was lacking power. Tried some other amps, Perreaux and Redgum but the Simaudio was more natural sounding. The Simaudio 5.3 pre/power is out of my budget

I am going to try the Meridian 502/557 combo on Sunday (but its a 2004 unit), the Modwright pre/power on Saturday.