Re: Question on JI timbres for "locking-in" partials

Hello, there, everyone, and here's a practical query for Dave Keenan
or Jacky Ligon or anyone else about just intonation (JI) timbres
which might bring out "locking-in partials" for small ratios on a
Yamaha TX-802 synthesizer.

I understand that sawtooth waves are especially recommended to achieve
a locking-in effect with simple ratios, and wonder if there are any
built-in voices which might especially bring out this effect.

Please let me express my thanks in advance for any advice.

Most appreciatively,

Margo Schulter
mschulter@value.net

Margo Schulter wrote:

>Hello, there, everyone, and here's a practical query for Dave Keenan
>or Jacky Ligon or anyone else about just intonation (JI) timbres
>which might bring out "locking-in partials" for small ratios on a
>Yamaha TX-802 synthesizer.
>
>I understand that sawtooth waves are especially recommended to achieve
>a locking-in effect with simple ratios, and wonder if there are any
>built-in voices which might especially bring out this effect.

I know the TX-802 uses FM synthesis, like the legendary DX-7. But I don't
know what timbres ("patches") are available on them. If it does General
MIDI then a sawtooth wave is GM patch number 82. But other timbres with
infinite sustain may be suitable provided they have no vibrato, chorus or
reverb. If you can turn off these effects, bowed string or trumpet
(unmuted) should be ok. Avoid woodwind.

Here's an interesting site with steady-state spectra of orchestral
instruments.

http://sparky.parmly.luc.edu/sharc/

A sawtooth is a standard that lets us compare results, but it is somewhat
cheating (as far as making complex ratios sound just) since its spectral
centroid and regularity (see the above website) are higher than most
natural sounds. For an ideal sawtooth, the relative amplitude (linear, not
logarithmic loudness) of the nth harmonic partial is 1/n. Of course any
real sawtooth will be band-limited.

Regards,
-- Dave Keenan
http://dkeenan.com

David C Keenan wrote:

> I know the TX-802 uses FM synthesis, like the legendary DX-7. But I don't
> know what timbres ("patches") are available on them. If it does General
> MIDI then a sawtooth wave is GM patch number 82.

I don't think General MIDI existed back then.

--
* D a v i d B e a r d s l e y
* 49/32 R a d i o "all microtonal, all the time"
* http://www.virtulink.com/immp/lookhere.htm

> > I know the TX-802 uses FM synthesis, like the legendary DX-7. But I > don't
> know what timbres ("patches") are available on them. If it does General
> MIDI

The TX-802 definitely predates General MIDI. It has some built-in FM timbres, but they do not at all match General MIDI.

Rick