Electric Piano or Bell Sounds

[chumpito]

Any suggestions on how to get a guitar to give bell tones or else sound like an elec. piano.  Not really chimy but those round bell sounds.

[LP Hovercraft]

You could try light ring mod mixed with a dry signal plus careful Band Pass filtering set with high resonance.  Craig Anderton's EPFM book has both of these effects (ring modulator and 3-band filter)

[Mark Hammer]

Robert Penfold had a project in Practical Electronics some years back for a "Light Metal Effect".  It is posted around in a pdf form.  Penfold refers to it in the guitar-to-synth interface project of his posted at my site (http://hammer.ampage.org).

Forget the veiled reference to heavy metal.  This has nothing to do with that.  The gist of the project is that it is a ring modulator-plus-pitch-to-voltage whose modulation frequency is proportional to the input frequency.  Normally, ring modulators have a fixed modulation frequency, with the output being the sum and difference of that fixed frequency and the input frequency.  The trouble is that the use of a fixed and varying pitch as the X and Y inputs means the ampount of detuning will depend on the input frequency.  So, if you modulate at 200 hz, an input note of 400hz gets you an output of 200 and 600hz.  An input of 1000hz gets you an output of 800hz and 1200hz, 2000hz gets you 1800hz and 2200hz, and so on.  Essentially the higher up you go the closer the sidebands are to the original such that it gets more "pitched" (i.e., sound like a boingey, but discernible, note rather than noise) as you increase the pitch of the input signal.  If you keep the modulating frequency low enough to make low input notes seem relatively pitched (e.g., use 500hz, rather than 200hz as in the examples), the higher ones lose their "boing".  Conversely, iif you make the mdulating frequency high enough to get sufficient boing out of the higher notes you expect to play, the low ones may be too chaotic.

The Light Metal unit tracks the pitch of the input, and systematically adjusts the modulating frequency (by the amount you set) to achieve a consistent ring modulation tone across the entire fretboard.  This way, if you want just a hint of intermodulation and detuning, you can produce it for every note played.

Just bear in mind that this is a decidedly MONO effect.  It can only do pitch-to-voltage conversion one note at a time.  Within those limits, it may be what you want.

[chumpito]

Thanks guys.  That would make sense, get a metallic sound, then filter it out.  I would like to use this with appregios so unfortunately pitch-to-voltage is probably not the solution.  I was also thinking of envelope shaping but that' probably not going to work on more than one note either.

[chumpito]

Okay well I've been playing around with ring modulators and eq/filters and I can get some very convincing church bells or clock strikes.  However, it's not very round or pretty like the vibraphone/ElecP. sounds I'm going for.  Any other suggestions for polyphonic EP sounds from guitar?

[Mark Hammer]

Certainly one of the "striking" aspects of a piano is the amplitude and harmonic envelope.  "Plucked" may be a cousin of "struck" but strings are not percussion instruments.  EP's have a different attack/decay cycle than strings do.  Perhaps you might want to experiment with some sort of dynamic expander (upwards, not downwards) to give you more "whack" on the attack?

[chumpito]

Thanks Mark, that was my original idea (well i was going to use an evelope shaper but...).  I think I will try to find some information on how to program a synthesizer patch for something like that.  I think that would give me a better idea of what needs to be done.

[RDV]

Take your B string and stretch it over the G string and hold them crossed over at the 7th fret, now turn on your disoverfuzzdrivestortion and strike the B string. You now have a church bell.

For whom the bell tolls!

RDV

[Mark Hammer]

My gut sense is that its going to be fairly difficult to mimic electric piano with guitar in the absence of hexaphonic processing.  Any time you need to derive envelope information about a note in order to alter its characteristics, you need to keep strings separate from the pickup onwards, at least if you're operating in the analog domain.

[bwanasonic]

The other thing that came to mind is two handed-tapping technique and right-hand technique in general. Fingerstyle techniques can get you a  lot closer to a pianistic sound. I like the sound I get with an envelope filter set for *reverse* or down sweep, a little tremelo and some reverb. By setting the threshold carefully, and playing fingerstyle, I can get some nice *keys* sounds.

Kerry M