My last clavichord project failed at the last moment, but not through lack of momentum. I got right to the point where I could play a full scale on it, but had to stop there, because I had learned enough from the project to realise that it would not work properly in the end.
The project I had envisioned was a clavichord built from very easily-sourced material: plywood. And the strings were made from high-tensile wire, using only one strand for the higher notes, and two or more for lower-frequency notes.
I didn’t actually expect to get as far as I did. My main intention with this project was to figure out exactly how clavichords work. This was a practice run.
Some mistakes learned from the last project:
- The key tangent positions are crucial. If they’re off by even the slightest amount, you will miss the string or (even worse) the keys will overlap with each other.
- When the strings are on, the tension created can warp the clavichord, making it bow in the middle, thus wrecking all your careful measurements and tunings.
- It’s very hard to find explanations online about how /exactly/ sound-boxes work, such as how to make sure all notes sound equally loud, where to place ribs (if needed), the effects of the various measurements and materials.
- Tuning is hard.
The new project will address these. I’m planning on building something which will address each of these problems, and also will allow me to test a few things I’m unsure of, and change things easily.
Firstly, the body will not be build as a solid rectangular block, as the last one was.
Instead, it will be built as a lightweight scaffold from metal rods bolted together. This allows me to easily re-arrange it if needed.
To stop the bowing, I will build a truss rod into the base, so if the strings cause the body to bend upwards, I can counter this by tightening the truss rod, pulling it back into shape.
To counter the tangent position problems, each key will be an adjustable three-part lever, which can be bent into shape, then “bolted” once it is correct.
Because the sound-box will probably be the hardest thing to get right, I have the idea of a removable box, so I can experiment with different materials and shapes. To make this possible, the bridge (which connects the strings to the sound-box) will be raise-able in its entirety, so the sound-box can be slipped out under it.
In a traditional “double-strung” clavichord, the string is looped around a tuning peg on the right side (next to the sound-box), pulled across the bridge, across the body, and looped around a pin, then back across the body, across the bridge, and looped to another tuning peg. I don’t really like the design of this, so will be changing it in mine.
In mine, each string will have a “ball end”, like a guitar string. the ball end hooks to the right end of the clavichord, and the string then is stretched over the bridge, across the body, then around a positioning pin and into a machine head. Machine heads are much easier to tune than tuning pins. This method also makes it easier to single-, double- or even triple-string different parts of the clavichord. In pianos, for example, the bass notes are single-strung using very heavy wire, and the treble notes are triple-strung using light wire.
I will also be adding a microphone and jack to mine, so the clavichord can be optionally amplified.
Some even more far-out ideas:
- Add a touch screen and small computer (Raspberry Pi?) which can be used to display sheet music.
- This could also be used to display a tuner, such as the awesome DaTuner Pro for Android.
- And the most difficult: automatic tuning. A robot mechanism for turning the machine heads and picking/tapping the strings automatically to tune to Well-tempered, Pythagorean, Mean-tone, or any other tuning.
Well – that’s the plan! Now to watch some Red Dwarf and forget all about this madness…