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Is there a way to record stringed instruments like zither, harp, piano via a pickup, similar to an electric guitar? Of course, these instruments can all be recorded via microphones, but what's preventing me from using a pickup?

Unfortunately, I don't know too much about the technology of electric guitars, so I don't know if there are fundamental differences. Do the strings have to be magnetic? Does each string need its own coil? Can I also use it to pick up brass strings? How wide can a single pickup be, can you build it wide enough to fit a whole harp at once?

The idea behind this was: the generation of sound with a harp or zither is comparable to that of a guitar. Could you build an "electric harp" that sounds similar to an electric guitar?

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  • Keyboard instruments with pickups have existed for close to a hundred years. The twanging rhythm part in Stevie Wonder's "Superstition" is an electric clavichord. Billy Joel uses an electric piano on "Just the Way You Are".
    – Kaz
    Jun 15 at 17:58
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You can record almost anything with a piezoelectric (“piezo” for short) pickup.

A piezo pickup works by generating a small electric current when it is moved or flexed. There are contact piezo pickups that you can essentially stick or glue on to any sound board and then when properly amplified (a mic preamp usually works well), you get a signal from the instrument you can record without using a mic.

People rarely actually do this because piezo pickups have a brittle sound quality that is hard to make musically pleasing. That said, if you have a lot of ambient noise and you must have a direct sound, this is one option. For larger sound boards, like piano or grand harp, multiple pickups would help capture the full range. That means each pickup has to be amplified, processed, and mixed, but this is done in special circumstances.

One very popular way to use piezo pickups on instruments with strings and soundboards is to combine a piezo pickup with a small, clip-on microphone that basically attaches to the instrument somewhere very close to the sound board. Mic distance is a great way to get signal isolation so even though there is a mic involved, it’s so close to the source that the ambient noise is drowned out. The piezo pickup compliments the mic nicely because the mic is so close that it can’t pick up all of the nuances. The combination works quite well and is used by professionals in live and recording situations all the time.

Regarding an electric harp or zither, there are some serious challenges. Magnetic pickups as used in electric guitars have to create a magnetic field that includes all of the strings and the field has to be very close to the strings. So designing such a pickup, or really several pickups, to capture all of the strings of a harp or zither would be a challenge and somewhat expensive. You could tack several guitar pickups to a board and arrange them to cover all of the strings (if they would all fit) at least as a prototype. The next problem is finding strings made from magnetic alloys of metal that are available in the gauges and lengths necessary for the instrument. For a zither you might be able to cobble together various electric guitar strings. For harp it might get tricky because I think the largest harps have strings that are longer than electric bass strings. But maybe you could custom make a smaller harp that uses a combination of electric guitar and electric bass strings. There would be lots of math to sort out the gauges and pitches and the resulting tensions. But it very likely could be done.

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  • Would the technique of using a small, close microphone in addition to a piezo work well for violins? I use just a piezoelectric mic on my violin (mostly in jazz contexts) and sometimes am dissatisfied with the tonal quality. Jun 14 at 2:19
  • @ElizaWilson Absolutely. I believe DPA is the most respected brand for these applications and they make a mic just for that: sweetwater.com/store/detail/… Looks like Audio-Technica and Countryman also make similar products Jun 14 at 4:10
  • "People rarely actually do this" True for harps. But it's worth noting that it's very rare (as in substantially less than 1%) to find an acoustic guitar using anything other than a piezo pickup on its own; and ditto electric violins, mandolins, and other similar instruments. No major manufacturer fits them as standard, so they are always custom fits, either with a high-end luthier-built instrument or as an aftermarket add-on. Harps are a small enough market that there is no financial incentive for anyone to produce a dedicated solution.
    – Graham
    Jun 14 at 15:54
  • ‘Brittle’, and ‘hard to make musically pleasing’ isn't my experience at all.  My first mandolin had magnetic-coil pick-ups, which I found harsh and unnatural (though no doubt suited to some styles of music).  Now I have one with a piezo pick-up; it's close to the acoustic sound, and works great for amplification and recording.  (It came fitted as standard, despite being an Ashbury which I very much doubt counts as high-end (even though I love it!).)
    – gidds
    Jun 14 at 16:15
  • @Graham That doesn’t match my experience with acoustic guitars. I see a lot of guitars both in the wild and for sale with factory installed pickup systems - some are just piezo systems but many (particularly Taylor’s Expression System and Martin’s two different systems) include multiple pickups with signal processing in the preamp to improve the raw piezo tone. I see a lot of pros playing mandolins and violins with combined piezo and mic systems. The fishman blender system was popular for many years. Jun 14 at 16:20
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It's not just theoretically possible to make an electric harp. You can buy them from at least three manufacturers, and I have one. It has piezo electric pickups, one per string. These are wired in parallel, and can be fed to any normal instrument pickup input.

Pickups can be added to an acoustic harp. These are normally glued to the soundboard. The post by Tetsujin links to Dusty Strings, who offer a kit with multiple pick-ups, to better cover the range of the instrument.

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Contrary to what some of the other answers have implied, there are actually a whole bunch of keyboard instruments with magnetic pickups, essentially analogous to electric guitar PUs. They all sound significantly different from their acoustic pendants, but that's in a sense a feature – some of these sounds have become legendary and now feature in almost any digital keyboard!

  • The Clavinet is almost the same as the baroque acoustic clavichord (a string instrument with a different hammer mechanism from piano), and indeed in single notes you can hear the semblance – but while the clavichord is infamously quiet and only useful for very delicate chamber music, the Clavinet benefits from the amplification option and has become famous for a relentlessly bright, highly rhythmic sound, best associated with funk songs like Stevie Wonder's Superstition.
  • The two most famous models of electric piano, the Rhodes and the Wurlitzer, both use magnetic pickup. However they do not have strings – the vibrating elements are solid metal plates. A Rhodes is actually rather an electric Celesta, rather than -piano, and that's the main reason these instruments sound very different from piano.
  • The Yamaha CP-80 (and its siblings) is an almost fully-featured grand piano, but built with the intention to be played amplified with its magnetic PUs, not acoustically.
    These sound much closer to an acoustic piano than Rhodes or Wurlitzer do, but still strangely sterile in the dry signal. Not too surprising – a completely clean electric guitar also doesn't have the depth / resonance of a mic-recorded acoustic guitar.
  • The Hammond organ uses magnetic PUs on tone wheels. This does not have an acoustic pendant.

In summary, it is absolutely possible to use electric-guitar-style pickups on non-guitar string instruments, but it doesn't make a lot of sense to retrofit an acoustic instrument with such PUs. They are mostly useful for processed, loud, possibly distorted sounds, in which case it anyway sounds basically like a different instrument. Indeed, even the “standard clean” sound people associate with the above instrument is actually result of amplifying them with a nonlinear, possibly tube amp without HF tweeter – again, like you do with guitar.

The only requirement for magnetic PUs is that the strings (or otherwise vibrating elements) are magnetic – which of course isn't the case for example for harps! However, instruments with non-magnetic strings could generally be redesigned to use steel strings, though that might again make a lot of difference to playing feel and certainly to the sound.

Piëzo pickups tend to reproduce the acoustic sound more closely than magnetic ones do, as well as not making any demands on the string material. Contrary to popular opinion the characteristic “magnetic sound” actually has less to do with the magnetic design per se, but rather with the fact that such PUs typically have very many windings, causing a high inductance which together with a passively-driven cable to the amp makes for a resonant low-pass filter. An active magnetic PU can be designed to reproduce the original spectrum quite well, though it will not pick up much of the body resonances. Therefore, to get an acoustic-like tone, you'll always need to combine it with reverb and/or additional microphones.

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  • This doesn’t seem to answer the question, which is partly about zithers and harps Jun 13 at 19:07
  • Well, it gives examples for very different instruments, demostrating that magnetic PUs can be used in versatile ways. And that it would be possible to design even a harp with steel strings and magnetic PUs, though how useful that would be I can't say. Jun 13 at 19:30
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You can't really do that as you imagine.

Yes, the strings must be steel - not only steel but magnetic steel [some steel isn't magnetic]

You don't need one coil per string, but it's useful if you have one pole piece from the magnet.
Your coil is going to be really, really difficult to wind for a curved zither, or a huge harp or piano…

… which is why we use piezo pickups on this type of instrument, if we can't mic them.

These are not recommendations, just the ones I found first
Zither - https://www.thomann.de/gb/shadow_sh_z1nfx.htm
Harp - https://manufacturing.dustystrings.com/harps/accessories-hardware/amplification/dusty-harp-pickup
Piano - https://www.yamahiko.info/en/products-2/piano-pickup

After comments - sure you can do this if you design the instrument from the ground up to work this way, but retrofitting is nowhere near as easy ;)

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An electric guitar pickup works by magnetic interaction between metal strings and a coil of wire.

What are sold as 'pickups' for stringed instruments other than metal-stringed guitars are generally contact microphones.

The Rhodes 'electric piano' used hammers striking a sort of tuning fork, each with its own pickup coil. That's about the nearest to a magnetic guitar pickup in a mainstream instrument.

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