I've just spent the weekend tuning brass reeds from an organ. It sounds like a very similar process, except you can grind both ends of the tongue to raise and lower frequency.
Funny you should mention that another hobby of mine was rescuing old harmoniums and making them playable again—you know, fixing and replacing reeds, renewing bug-eaten felt, sealing rat holes in the bellows, etc.
I grant you it's not in the same league as voicing a diapason though. :-)
I reckon adjusting and tweaking things goes with the territory. I'm pretty much at home tweaking crystals, fixing reeds, aligning IF stages in radio and TV equipment, there's much of a sameness in the way one tackles all of them.
BTW, I've actually repaired reeds by soldering them. Not a good fix though as the solder can fatigue with use. Throws out equal temperament a bit too but most can't hear the difference.
By 'repaired' you mean closing a fracture? I'm interested to hear your experiences! Electronics solder or silver solder?
This one is 60 cents sharp across the board (not uncommmon), but I wanted a social instrument. So I brought them down with solder. The bottom two octaves have worked out well. The next two... we'll see. I now have the fear that I've weakened the brass by heating it. But it still sounds nice and speaks well. Fingers crossed.
Right, I haven't had many fracture but it was more than I expected. I've had some come apart (completely—shear off). One I recall fixing (replacing the reed) with a piece cut from a phosphor bronze shim several thou thick (I had various thicknesses). Replacing the reed was easy but voicing was a problem because p-bronze has different properties to the original. It was a long while ago so I can't remember exactly what I did but it worked—sort of. I eventually got it roughly in tune but it was a different volume to the others.
About two weeks ago I was up at my old family home for the first time in years and there are two harmoniums dating from the the mid to late 19th C. which I meant to fix years ago. The woodwork on one is particulary ornate and in excellent condition. They both have dead keys when I played them. Reckon I've some wok cut out for me. .
Adding solder has also been frequently used to correct the resonance frequency of quartz crystals that have been ground too much, and I mean during industrial mass-production, not only in a home-lab setting.
How are people sticking stuff to quartz? I know less than nothing, but the pieces of quartz you find in rock don't look like they'd take a solder bond.
I'd assumed that with piezo crystals etc there was a mechanical connection rather than an electrode bonded to the crystal?
But if you can add solder presumably there is some kind of molecular connection with the metal?
Electrodes are deposited on the crystal in vacuum, e.g. by metal evaporation or sputtering, in the same way as they are deposited on the semiconductor crystals used to make transistors or integrated circuits.
The electrodes may consist of multiple layers, a base layer that adheres strongly to quartz and a top layer that is solderable, e.g. made of nickel or silver.
The pins of the package that hosts the crystal resonator are soldered on the electrodes, in places well chosen so that they will not damp much the oscillations of the crystal.
When the mass of the crystal must be increased to shift the resonance frequency, excess solder may be deposited on the electrodes.
There is already a silver patch bonded to the crystal where the wire connects to. Adding weight to that obviously will not make the load curve any better but if you do it with just enough to drop you back down below where you wanted to be then it can be a saving move. You could also put a trimmer in parallel, but that might not have enough range (and can also end up overloading the crystal so the oscillator won't start).
Oh that is so cool. I played the one in Liepaja, Latvia for a bit and it was absolutely amazing. It's love/hate for me (like the harpsichord), I love the instruments but I usually do not like the music that is played on them because of the grating effect. I have pretty bad tinnitus which really spoils a lot of music for me, extremely annoying.
Ha-ha, I didn't read this until I'd written the above reply, seems we have something in common.
Incidentally, I'm one of those mad people who'll put on a recording of Helmut Walcha playing Bach's Passacaglia and Fugue in C minor on a Silbermann and turn the volume up until the room shskes.
I would just attempt it all and see where you get stuck. But one step at the time with total focus on that one step. I've done a lot of instrument repair over the years and the first one of a new class is always the hardest. So rather than to take the whole thing to pieces I'd fix just one aspect of it, reassemble and enjoy the improvement. Then fix the next thing. It's much more work than stripping the whole thing down but it keeps the gaps in your understanding small enough that you won't end up with a pile of parts rather than an instrument.
I've been trying to remember the name of a particular instrument for you for the last 24 hours but so far no success, if I recall it I will post it here.
And, if you're sneaky, you can add solder.