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Originally Posted by crowmadic  Is my logic off when I think that valve alignment's main objective is to make sure that casing ports and valve holes are perfectly aligned so the horn has its optimum air flow? To accomplish this pads and guides are used. Properly done this should leave the valve buttons at an equal hight. I would think that when this is done correctly the nature of the horn takes over as far as slotting and pitch. This being said, I don't see why valve alignment is so difficult to do. |
It's not hard at all IF you are doing it on a decent horn, you've got the right spacers and equipment to see both the up and down positions and you know how to use a micrometer/caliper.
The problems start when the port spacing and the slide spacing aren't equal, as in my Schilke. When those differences are small, as in my Schilke, the tech has to reach a compromise. Mark Hammelev did this for me and the result is fantastic.
I took one of the black lacquer Holton Committees to Mark and every valve was a compromise. He worked on the valve ports themselves, which had lips here and there where the wholes in the valve surface didn't align with the port through the valve (improved with some filing). There was a leak, etc. All the things taken together took a horrible trumpet and turned it into a very good trumpet. (It went from 40th percentile to 90th, in my estimation).
Mark looked over and played my Stomvi Master piccolo and declared no need for a PVA. (It's possible that a PVA was done by Reeves, since Cambrass offers that service on new Stomvis).
So, some horns are very easy and only take a few minutes. Others require learned compromise.
With Monette, mentioned earlier, I'm guessing that there are not port/slide alignment issues and that lead to compromise on the alignment and the process will be very straightforward. (For a trumpet that expensive, I'd expect them to get that parameter absolutely right).
Dave