John EricsonAnother of my current projects not yet posted about is the Mirafone Kruspe. I’ve made a lot of progress on this one.
My goal
This project actually goes back a LONG ways, in my mind at least. Years ago I wondered what you might get if you copied a good example of a vintage Kruspe just as closely as people try to copy a good vintage Geyer?
So when I saw this Mirafone double horn, apart in two places and the thumb valve lever off, it appealed to me as a project, as I had an ace up my sleeve. I also had a Mirafone single that has a great, medium bore bell — the body of which (.450 bore) is being used to reconstruct a Schmidt inspired single horn, with a vintage Schmidt bell.
The original bell with this double was huge. So goal one was to get the parts ready and set up to mate the double horn first branch to the older bell. As below.
That bell looks great doesn’t it? It’s hand hammered with a gusset and has that garland as well.
Working on this horn I was also referencing my vintage Kruspe double, matching details when possible. Often, I could not make things match, but sometimes I could. One of the big ones, is I changed around the bracing scheme between the first valve and the main slide tube. On the Mirafone as built they were connected at the second tube, but on my Kruspe they did the connection at the first, and I changed it to match that.
Order of operations was a puzzle, with some enforced by the fact that this was a heavy repair job. A big issue was that, as built, they forced the longer F branch into place but it was more than 1/4″ off. I annealed the middle of it, filled it with Cerrobend, and worked it out so that it is now the correct length.
And it looks like it will work.
Well, it’s not perfect. The joint I’m pointing at, I could not get it apart. I’ve ran into this on another Mirafone horn, the parts have such a tight basic fit that it’s very hard to get them apart. Well, I could have gotten it apart but with a high likelihood of damaging some critical tubing.
This area was damaged and repaired previously. But not repaired that well, which is why the thumb valve mount had fallen off.
When they built this horn they probably had a very specific and helpful assembly jig. I don’t have that, and had to work out the bracing and fit of parts. I did as well as I could. Another brace that I added is visible in the above and below photos, the extra brace between the first branch and the F return. My Kruspe has that brace, I hope it adds some magic to the horn.
After taking this last photo I did get the thumb valve mount back on. The tube that leads between the thumb valve and the first branch, its on at a slight angle, which created a problem for mounting that piece. I think it’s now on very solid and at the correct angle. I’ll know better soon! As this horn will be playable again in a few days, enough so that I can test my mouthpipe options. But have to clean up everything well and reassemble the valve section first.