fwd: RE: practical vs. theoretical implementations of micro...

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Original Text
From: John Loffink@HW Stor@Sys Hou, on 12/20/96 9:24 AM:
To: smtp[tuning@eartha.mills.edu.]

Re: practical vs. theoretical implementations of microtonality

This discussion is based upon several false assumptions. Some
corrections....

1. There is no such thing as a Kurzweil K3000. You must be referring to
the K2500.
2. It is very simple to do octave shifts of instruments. Multiple pitch
tables are not necessary to do more than 17 notes per octave for a piano
range instrument. If you need instruments with 250 discrete pitches,
assuming that they repeat by octaves, you can create the pitch table once,
copy the instrument and then merely shift the pitch by octaves to create
the full scale pitch range. This is not possible with the Ensoniq series
of samplers however (see next item).
3. The author seems to be mistaking the architecture of the Ensoniq series
with other manufacturers instruments as well. The Ensoniq samplers cannot
store the program parameters (tunings, filter settings, etc.) separate from
the sample RAM. This is one of the great weaknesses of the ASR-10. The
other is the limitation of loading 8 instruments. Kurzweil and I believe
E-mu and Akai can and do allow multiple program settings using a common set
of samples. So all these calculations starting with a 32M sample bank and
then multiplying it by X times are wrong except for those using an Ensoniq.
To do the octave shifts one merely needs to copy a few hundred bytes of
program RAM and readjust the relevent parameter.
4. The assumption is made that tuning tables are the only means of
creating a non-12 note scale on instruments without full scale tuning
tables. This is correct only when talking about non-equally spaced scales.
For equal tempered scales on the Kurzweil K2000 and K2500, it is very easy
to adjust the keymap tracking parameter to a rough value so that the
individual samples track the pitch range they were intended for. One then
adjusts one of the two available pitch modulation sources to fine tune the
pitch tracking to get a tuning accurate to +-1 cent over the entire MIDI
range. Since the Kurzweil gives the pitch tracking modulation depth in
real units of cents, it is very easy to calculate the proper values for any
equal tempered scale, including non-octave repeating scales such as the
Carlos alpha, beta and gamma scales. I recently gave an example of this to
a tuning list member for 19TET and I believe he forwarded those parameters
to this list. On the Kurzweil instruments this is stored as a program
parameter in program RAM, not in sample RAM. The K2000 and K2500 are
limited to 999 programs per instrument. I believe this to be an adequate
number for most users even though you would have to use separate programs
for the same sample set in 19TET and 31TET scales (but again, no extra
sample RAM). Any one of these 999 programs are instantly available by a
MIDI extended program change message. Multiple ET scales could even be
mixed within the same composition and sequence. It takes a few minutes to
calculate the parameters for a new ET scale and about 30 seconds to program
each instrument.
5. The K2500 and Emu EIV both allow 128M of sample memory. The lowest
cost Kurzweil option is to get a K2500R (Rack) without the sampling option
for about $2500. You don't need the sampling option to use samples, only
to do your own sampling from microphone, line or digital inputs! The SIMM
slots and SCSI interface are on the basic unit. 30 pin 16Mx8 RAM is
currently running $95-$120, so the full 128Mbyte cost is less than $1000.
Of course, the assumption that you need this much is entirely wrong. Add
64M RAM, the Program RAM option, a SCSI CD-ROM drive, a 1 or 2 Gig hard
drive and several sample CD-ROMs and the total price ticket is $4000-$4500.
Yes, this is expensive, no doubt about it, but it is also one hellaciously
powerful system.
6. Software updates do occur, especially for the more expensive instruments,
so the situation is not entirely hopeless. I urge everyone to contact the
manufacturers and request microtonal tuning capabilities. Make sure they
know that your purchase decision is dependent upon this feature. I am
personally working with Kurzweil on these matters and would love for other
manufacturers to be responsive as well. One problem is that there is no
consensus as to what microtonal users want. One user may want only a few
full keyboard tuning scales while another may want dozens of octave based
scales that can be selected on the fly for complex just intonation
modulations. And let's be realistic, no mass market manufacturer will
support resolutions to .01 cents or better because the VLSI chips simply
aren't that accurate. Users needing this accuracy will have to rely on
specialized systems like KYMA or the Justonics synthesizer.

For Marcus Hobbs:
The literate I've seen on the Ensoniq MR Rack says it has only one RAM
tuning table location. Is this incorrect?

John Loffink

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