Wavetable technology

[The Dark force of dance]

Y-ellow Lucas 'n' all.

At 09:17 PM 26-04-98 -0300, Lucas Medeiros Reis wrote:
>What is Wavetable Technology? In which keyboards can I find it? Is it the
>same as virtual analog?

It depends on what you call wave-table technology. Most sample playback
engines destined for computer sound cards hijacked the term to mean that
they have a bunch of ram which is seen by the synth-engine as a look-up
table of sample data. Which is kinda true but in reality they are more aptly
referred to as above. A sample playback engine.

Wolfgang Palm first coined the term as far as I am aware. To refer to his
wave-table synthesis used in the PPG, and now the Waldorf range of
synthesizers. The PPG wave family of synths were/are digital/analogue
hybrids. Back in the early 80s when they were shiny and new, digital
technology was big clunky and expensive. Memory was a fairly expensive
resource so no-one wanted to use any more than necessary. Wolfgang Palm,
thus PPG, (Palm Products Germany) devised a way of reducing samples into
sample tables. In the wave2.3, the only PPG synth I had, there were 64 waves
per table. Each wave was a complete single cycle of a wave from. Each table
would make up an entire transient for a single sound. A piano or a sax for
example. Though there were some other more interesting sound to choose from
in the wave. A kind of quasi analogue sequencer would sweep through a
selected wave table backwards and forwards playing out the various wave
forms. Because each wave in the table was a complete cycle, there would be
no issues of looping and loop-points because they were all designed to link
up perfectly no matter what. The sequence of which waves got played back
from an individual wave table could be determined by an envelope generator
or an LFO. Or any number of other sources. It could be made to start at any
given point in the wave table, dwell upon a small few whilst the key is held
and then drift off back down the table when the key is released.

To polish off the system, Palm included complete analogue filter and VCA
sections for each of it's 8 voices. The wave table synthesis became the
equivalent of the VCO if you like. The vocal cords followed by the mouth.

You really have to appreciate what Palm did when he started working on this.
It was unique and back in those days, must have taken considerable effort to
create all the wave tables. There were no tools available to do such things.
He had to build his own. Later he turned these tools into another product
called the "WaveTerm" Which we also had for the 2.3. Basically a computer
system which could perform a fourier analysis of a sample and convert it
into a wave table. It could do much more than that but that is essentially
what it was for. It connected to the PPG via what looks like a big GPIB
interface. Though this is probably totally proprietary. All the wave tables
were only 8 bits wide.

Hope this helps.

be absolutely Icebox.
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