Magnepans

I did not read all the posts, so if this is a repeat, I'm sorry. 
The Avatar is a great amp, first of all. I love it, owned one. Second, Kevin Hayes, owner, designer of VAC, would be your best source of 'What if'.
He will be completely honest.
BTW, the Maggies, are an almost flat, IIRC 4 ohm load.
Also, someone mentioned the 60 Day Trial, I'd do that.
Good luck.
Larry

Tim,
Can you mod a 1.7 with a true ribbon in the tweeter? 

I have the Avatar you have, and I once had Magnepan Mg2a's.  First, old Maggie's can have a problem with the glue deteriorating, and it's not always obvious to the listener.  Second, I wouldn't think this is a good match.  Maggie's seem to need a muscle amp with lots of current, and I think a lot of purchasers are disappointed when they try to make a smaller amp work--me included.  I had a well-respected 100 watt Sansui, but not enough grunt.  I've never seen them demoed with a low power tube amp, which should be a clue.

A friend and I stopped by Shelly's Audio in the San Fernando Valley one day back in the 80's. They had a pair of 3.1's in the showroom and were driving them with a pair of VTL "Tiny Tots" ... tube amps putting out only 25 watts per channel. Gotta say, within the power range, the sound was simply glorious. You wouldn't want to use these amps with Maggies on a full time basis of course, but as a simple experiment, it was really good. 

Those little VTL Tiny Tots are as rare as hen's teeth now. 

I would not get too caught up in the whole true versus quasi ribbon question.......a quasi ribbon is ANY variation on a true ribbon, which is simply a ribbon in air w/ voltage applied......In the case of the 1.7i's, the quasi ribbon consists of a TRUE RIBBON applied to a mylar film, whereas in the case of the 3.7 and 20.7 loudspeakers, no mylar film......that's it!

Whoever said that the 2.5 sounds better than a 1.7i needs to go hear the 1.7i (and he said he had not)......I have heard both of them (in the case of the 2.5 though, it was a quarter of a century ago!)

The 1.7i's have a wonderful musicality with less bass than the 3.7i's, but in a small to medium space, you'd likely not miss it......we're talking 3x the cost to go to 3.7i's, but there are bargains to be had on 3.7's, in the 3k to 3.5k range........

If I were the original poster, I would absolutely dismiss purchasing a loudspeaker going on 30 years old......The current stable of Maggies are night and day different now in terms of coherency and musicality......it would be much like having a quilt removed from the old speaker.......and quasi ribbon versus true are TRIVIAL matters.....

In my mind the choice would be based on size of listening room and what you could make work aesthetically.......1.7i if space is limited and 3.7 or 3.7i if it's not (you can always upgrade the 3.7 to i status later for 500.00 plus freight......

The 3.7s are wonderful but the 1.7i is cut from the same cloth......

Here is a video of 1.6's, which the 1.7i's obliterate in my opin:
https://www.youtube.com/watch?v=bRsVxyNiAOY

Here is a video of my setup back when I had the 7 amps:
https://www.youtube.com/watch?v=F8KkhdoYLZU

Just after adding 28s:
https://www.youtube.com/watch?v=rgmHbORQ5Ew


How good are the 3.7s?

Least costly component in my system by a very large margin
and they're not going ANYWHERE.........they are not for sale.....and probably won't be for a very long time........