The Vali2 is less than twice the price of the ember, I live in Canada so the exchange rate will play a big role.
Is the Vali2 worthwhile after switching out the stock tubes? Apparently the stock one is very neutral sounding.
I'm a fan of the Lyr.
It's kind of a "both worlds" amp, you can go solid state or tube on it.
I tend to like neutral/flat, as I prefer to have the music available as it is recorded/mixed at the studio, as the artists desire it to be presented.
Mess with EQ if I'm not happy.
Now, that being said.... for your Senns, you could consider a Woo product. I have the 600's,(among a few other Senn offerings), and I tend to use a WA6 for them. It's a SUPER amp for tube rolling!
You can get into all kinds of tubes on it, and some of the most pleasing tube combos are surprisingly inexpensive.
It's amazing how many NOS tubes are still around that are either under-rated or not trialed enough to get much review.
AND there are THREADS GALORE here about tube rolling on the WA6.
It's a little workhorse that many a happy Headfi-er has, or has had in the inventory. It's an amp that has headed many a Headfi-er down the vortex of the tube amp.
And they can be had, from time to time, on ebay or here in the FS section, or several other locations online, although with the caveat that other sites might not be as trustworthy as ebay and Headfi are.
You can buy tubes here and on ebay. You can get upgrade sets at Woo.
I even have a spare WA6, for goodness sakes.
I don't think you can go wrong with that as a tube amp for your Senns, it can drive many other rather demanding cans as well. So it can drive you further down the tube amp road, should you acquire other headphones that a tube amp would be nice for.
A tube amp can take some very clinical sounding cans into the realm of liquidy organic heaven and is well worth the investment.
oh. There are several Canadian purveyors of tube amps out there, you should search them.
Ebay and Headfi sales also may help with your concerns over this, you might find a Canadian seller to meet your needs.
There are several of us Canadians around here, dontchyaknow.....