Doug: Knopf horns, at least Herbert Fritz Knopf horns and possibly August Knopf horns, do not have serial numbers. If the first valve is the big problem, I suggest taking the horn to one of the really great horn repair people mentioned in previous posts to have the valve removed and checked. Typically, valves are a bronze-brass alloy depending on the vintage and maker. The nickel plating immediately suggests that the valve has been plated and refitted into the casing (not necessarily that particular casing from your description). As several posters have pointed out, the valve assemblies are generally supplied by a few specialist makers, so the possibility exists that a replacement valve can be found if it turns out that your present valve is beyond repair.
If this is a vintage horn that plays as well as you say, I would be very reluctant to chop the bell. So much for the free advice...and opinion :-) Richard in Seattle On 3/28/2010 9:43 PM, [email protected] wrote: > > I would like to thank everyone who replied to my original post (I thought > the whole point of this site was to get "free advice.") There are a couple of > things that I would like to make as clear as I can: > > There are no markings on the horn that I can find to identify this horn other > than the 'Knopf stuff' on the bell section. I can find no serial number, or > the like, anywhere on the instrument. Is there someplace I haven't looked > that I should? > > The 'stuff' I got out of the horn with the cleaning I did (confirmed by the > shop that did the ultrasonic cleaning) was black. Some of it was shaped like > the inside of the tubing. I don't know if that was old slide grease that had > dried out, or if it was actually part of the horn. For all I know, the black > stuff was protecting the inside of the instrument. But, if it is some sort of > rot that changed the taper of the leadpipe or the inside diameter of the > horn, I'd like to know. > > The thumb rotor, second and third valves are all, if I'm not mistaken, raw > brass. The first valve is nickle plated. When aligned, not just by the marks > but by looking as best I can down the tubing, using mirrors when needed, the > first valve leaks (quite a bit) and the others don't. This is using simple > tests taking out a slide, depressing the rotor, blocking the tube and blowing > air. All are tight except the first. Also, the first valve doesn't ever > visually 'line up.' So I think it's safe to deem the first valve 'different.' > > Getting the bell cut will probably wait until the rest of the work is done. I > had one individual reply off-line with the idea of having the ring soldered > onto the horn without actually cutting the bell to simulate having it cut. > That sounds reasonable to me with an instrument like this. But I don't think > cutting the bell would have the kind of impact something 'upstream' would. > Like changing the leadpipe, a valve or some other component. I expect it will > change, but the degree to which it does...? The reason I bring it up is: with > a compensating horn there is less tubing than a full double - making the bell > more significant. Also the lightness of the horn as a whole and the bell > section in particular, adding a ring would certainly be more significant than > it would be to the Pax 20L, for instance. I guess the jury is still out on > this one. I'll keep you posted.... > > > > Doug > > Life is a terminal disease - live with it. > > > > > _______________________________________________ > post: [email protected] > unsubscribe or set options at > https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/hornfella%40comcast.net > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.791 / Virus Database: 271.1.1/2776 - Release Date: 03/28/10 > 11:32:00 > > _______________________________________________ post: [email protected] unsubscribe or set options at https://pegasus.memphis.edu/cgi-bin/mailman/options/horn/archive%40jab.org
