root (05/12/82)
I am interested in any experiences anyone may have had along the lines of building a computer driven synthesizer system, be the synthesizer analog or digital. I would especially like to hear from anyone using a PAIA product. Jim Binkley mail address: ...ucbcad!teklabs!tekmdp!dadla-b!james
bufford@ihuxw.UUCP (S. C. Smith) (06/19/84)
Hey, world! Help? As a piano player with a desire to experiment and some $$ to spend, I find myself in the market for a "getting started" synthesizer. I'd prefer 5 octaves, with the ability to play around with wave shapes, attacks, etc., so it appears that "electronic keyboards" without the ability to do some elementary programming would be the wrong way to go. The Roland JX-3P begins to look like the right ball park. Anyone willing to offer some advice? Thanks, Steve Smith ihuxw!bufford (don't ask) 312-979-0716 AT&T-Bell Laboratories, Indian Hill
ken@turtlevax.UUCP (Ken Turkowski) (06/23/84)
The Yamaha DX-7 seems to be a really nice machine, although it performs
differently than the Roland. The Yamaha uses Frequency Modulation to
get its rich complement of sounds, while the Roland uses Harmonic
summation (I think). It goes for $1995, and its little brother, the
DX-9, goes for $1395.
--
Ken Turkowski @ CADLINC, Palo Alto, CA
UUCP: {amd70,decwrl,flairvax}!turtlevax!ken
Posted: Fri Jun 22 18:54:29 PDT 1984
--
Ken Turkowski @ CADLINC, Palo Alto, CA
UUCP: {amd70,decwrl,flairvax}!turtlevax!kentynor@uiucuxc.UUCP (06/29/84)
#R:ihuxw:-89400:uiucuxc:30800022:000:1762
uiucuxc!tynor Jun 28 21:14:00 1984
Actually I think that the JX3P (as well as most other synthesizers
with 'digital oscillators') uses a form of 'table lookup.' This works
as follows: imagine a string of numbers representing the amplitude of
a waveform. the table for a sawtooth might look like:
0 1 2 3 4 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 etc.
Actually, only one period of the waveform is really needed (ie. 0 to
-1) The table is not necessarily sampled one number after another.
It may skip one or two (or 2 1/2... here we get into interpolation
problems...) the rate at which it samples the table is dependent on
both the dac (digital to analog converter) sample rate and the
frequency of the desired pitch. It's a simple way to simulate a
waveform.
After you create the sawtooth, the JX3P (and again, most other
synthesizers on the market...) the signal is routed through a filter.
the effect of this filter is to *subtract* harmonics. So actually
the JX3P is an example of a synthesizer that uses Subtractive
Synthesis.
I like the JX3P. It might be a good synthesizer if you don't plan on
doing too much of your own programming. If you do, however, you'll
probably want to add the clip-on programmer (It makes tweaking the
parameters a heck of a lot easier) It also makes the JX3P a couple
hundered dollars more expensive.
Also. listen to the Yamaha DX-7. As a pianist, you'll like the extra
control available due to its velocity sensitive keyboard. And the
sound beats everything else I've listened too. If only the price
would come down (Rock steady $1995... no deals. It's a hot item and
Yamaha is having a hard time keeping up)
Steve Tynor
ihnp4!uiucdcs!uiucuxc!tynor
University of Illinois Champaign-Urbana