The Mudcat Café TM
Thread #16742 Message #3361025
Posted By: JohnInKansas
08-Jun-12 - 04:56 PM
Thread Name: Tech: Electronic Tuner for Autoharp
Subject: RE: Tech: Electronic Tuner for Autoharp
This thread went dormant 12 years ago, and a magnetic pickup is a little off the original topic, but prior comments didn't really stick too close to anything in particular, so the little bit of thread wander isn't really a problem.
Prior comments about tuners and tuner pickups were a little off the mark - or at least a little incomplete.
Since an autoharp has a whole bunch of strings to tune, it's obvious (I think) that you need a chromatic tuner. The simplest tuners on the market are really intended only for guitars and the like and might get confused with "too many notes," so you may want something a little fancier, but any tuner that can "hear" all the notes you need, and that tells you in a reasonably handy way how close you are should suffice.
The clip-on pickups that you attach to the instrument and plug into the tuner are a real help in getting what the instrument is saying without picking up what everybody else's instrument is doing, but they're very slightly more complex than just a wire and an alligator clip. The wires at the "clip" end have to connect to a "piezo element" as DonMeixner (08 Jan 00 - 04:50 PM ) described. A "piezo" element is anything that produces a voltage when you shake, squeeze, or bend it. When the instrument vibration shakes it, it makes a voltage, and that voltage is what's fed into the tuner.
You can make your own clip on tuner, but unless you've got a well-stocked junk box and have saved a variety of "broken things" it's generally cheaper - and a lot less hassle - just to buy one ($9 - $15 (US) last time I looked). Piezo elements are "findable" in a lot of things, both for detecting sounds and for making sounds. One half the size of the littlest pea in a pod (the one that didn't grow) should suffice for a tuner pickup, but I've seen them up to about 2" diameter in the alarm clock "screamer" of the kind sold in truck stops to wake up the trucker sleeping in the middle of a yard full of running reefers.
The clip-on tuners just have the piezo pickup in the tuner.
When you say "magnetic pickup" I assume you're referring to a pickup intended to detect what the strings are doing while you're playing so that you can amplify the wiggles to make things loud enough for the surly crowd to hear. These things are generally intended to be permanently installed, usually inside an instrument where they're pretty well protected from "violent events" so they can be made quite tiny and outside of normal use the itty-bitty parts can often be easily damaged.
There are lots of variations in magnetic pickup designs, and about the only ones who can really tell you how a particular one is put together is the one who put it together - so beating up a manufacturer's rep is probably the most effective approach - if you can tell which one to hit on.
The only reference to a "442" I found at the O Schmidt site was for the "EQ" version, and it doesn't give enough info even to tell whether uses piezo or magnetic pickups. There are ads on the web offering a "442 pickup kit" for addition to an autoharp that isn't wired for sparks, but the "complete installation instructions" they advertise may not really be helpful for broken things (and they don't actually say whether that's the same one O S uses).