| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 60.1 | | BARNUM::JWALTON | | Mon Feb 11 1985 13:03 | 24 |
| Eventide, Ibenez, and MXR are the only ones I know of
who make Harmonizer/pitch transposers.
The Ibenez works by having to delay lines in parallel
while one is sampling the input the other is clocking
out at a rate that is front panel controlled (your pitch
shift) then the latter line goes to sample and the former
does what the latter did. (???) Is that clear??
Eventide has a new one that is supposedly glitch free.
I don't know if I've ever heard the MXR, but I think
it would sound the same as the Ibenez. Which is not great.
$$$$$
Ibenez - ~$500
MXR - ~$1100
Eventide - ~$4500
I don't know how you would control a keyboard with it though.
(If that's what you asked, I can't see your original note now
bad planning)
John Wlaont
err. that's Walton
|
| 60.2 | | PIPA::JANZEN | | Mon Feb 11 1985 13:21 | 22 |
| If that's the way it works, the delays aren't in parallel they're in serial.
INPUT------|
V
********
* * Signal
*DELAY *--------------------|
* * |
******** V
^ ********
IN CLOCK---| * *
*DELAY *------OUTPUT
OUT CLOCK------>* *
********
THAT WOULD be pretty glitchy. That's not what I want. I want something
that plays chords automatically. I tell it I'm in F major, and when it
hears me play an F it plays an F major chord; if it hears an E it plays
a C major chord. like that.
TOm
|
| 60.3 | | BARNUM::JWALTON | | Mon Feb 11 1985 17:47 | 27 |
|
No it's like this...
input ********** #######
------>* memory *------# VCA #----------
********** ####### |
^ ^ |
| | |
| | |
input ********** ####### |
------>* memory *------# VCA #----------X-------> output
********** #######
^ | ^ |
| | | |
CLKA CLKB CVA CVB
CVA and CVB are 180 degrees out of phase. I don't know the waveform
but would think it's roughly a square wave. As CLKA runs at input
clock rate ~Nyquist frequency = 11KHz -> CLKB will run at a rate
equal to CLKA(degree of pitch shift). When the CV's change the
CLK's exchange rates.
You have parallel circuits performing alternate tasks 180 out
of phase.
John
|
| 60.4 | | BARNUM::JWALTON | | Mon Feb 11 1985 18:06 | 32 |
|
Sorry about that.....I got lost, like off the track/road
by a mile.....
But, to answer your question about getting your keyboard
to play notes only in a specified key in response to notes
from an acoustic source.....did I get that right????
I don't know.
If your going to use say an acoustic guitar or a violin
or a trumpet I don't think you've got much of a chance (I
hope I'm wrong) frequency-to-voltage converters aren't great
for that stuff PLL's though might do it. You would need to
some kind of dynamic expansion in order to keep your source
signal dynamics within the dynamic range of your curcuitry,
also most front-ends for these applications 'like' to have
a clean square or pulse wave, locked on the fundamental,acoustic
instruments have a nasty habit of containing harmonics that
tend to fluctuate in energy. That is, during the course of
the note the second/third harmonic will gain enough energy
over the fundamental and the PLL will lock on that, Kind
of like a yodle not unpleasent, but you can't always anticapate
it.
Anyway I've got some specs on chips of the expander,
F-V and V-F types if you would like copies of them.
A guy from PRIME (yow!!!) gave them to me!!!
Send E-NET mail if you want them (mail-stop) and I'll get
it out on inter-office as soon as I can.
John
|
| 60.5 | | PIPA::JANZEN | | Tue Feb 12 1985 08:33 | 2 |
| Thanks. I have more data books then I need. to build NORAD.
Tom
|
| 60.6 | | PIPA::JANZEN | | Tue Feb 12 1985 14:51 | 17 |
| I know what you mean about harmonics. Last year I built a simple circuit
that followed a pitch at the pitch or one or two octaves below. The
movers lost it. Maybe that's all a harmonizer is. I should build it
again with PLL's to get parallel chords.
9V power|\OP AMP *******
| \ *CMOS *
LINE IN----------| /------*F/F *********|
|/ ******* |
> voltage divider OPAMP
< |\
> | \
------------------| /---OUT
> |/
<
___
_
TOm
|
| 60.7 | | BARNUM::JWALTON | | Tue Feb 12 1985 16:54 | 15 |
| Here's a good one for frequency offsets (+,-)....
input Voltage output
-------> PLL --------> VCO ----------------->
^ |
| |
--------------------------
signal feedback loop
In the feedback loop you can put dividers (F/F) or an OP-AMP
to drive the VCO to frequencies other than the input. Also
put conversion circuitry in the Voltage line.
John
|
| 60.8 | | DCVAX::SBROWN | | Tue Mar 26 1985 20:49 | 16 |
| Anyone out there ever heard of Zappa's Electro-Wagnerian Emancipator?
I don't know much about it, but it sounds like a harmonizer, and was
probably done with fairly old (early 70's) technology.
I've often wondered what it would take to build one of these beasts, and
have filled the bacls of envelopes with chicken scratches about PLL's,
Schmitt triggers, filters and whatnot. The ultimate problem as a musician
and composer was getting beyond the simple octave or triad sounds produced.
If you want to get into modal harmonies and the like, it's probably just the
thing, but otherwise I suspect you'd need some more hands to work the conttrols,
and then why not get back to keyboards. My instrument is the trumpet, and I'd
like to play with some of the sounds that I hear coming from John Hassel, where
the trumpet is more of a controller than a melody instrument. So I can see a
need or desire to do this. Would a guitar synth help?
-seymour-
|
| 60.9 | | PIPA::JANZEN | | Mon Sep 30 1985 08:39 | 13 |
| PIPA::JANZEN * Integrated Circuits * 27-SEP-1985 09:04
Note 47.7 -< SAD1024 ? >- 7 of 7
The Reticon Analog Signal Processing Integrated Circuits data and
applications book (Spring 85) which just arrived from East REgional Office
35 Congress St., Salem, MA, 01970, (617)7457400, does not have this part,
but does have more up-to-date versions of the same function.
The application notes are about pitch transposers and reverbs and signal
processing filters.
The pitch transposer articles are in reference to tape recorders that can
play at different speeds without changing the pitch of the speaker on the
tape..
Tom
|
| 60.10 | Digitech IPS33 intelligent pitch shifter | ANT::JACQUES | | Wed Aug 09 1989 10:59 | 28 |
| One harmonizer that was not mentioned (and is perhsps the best all
around harmonizer for the money) is the Digitech IPS33 "Intelligent
Pitch shifter". It sells betwee $600 and $700. It has midi in/out/
through jacks, and has about 100 to 200 memory locations. Half the
memory is full of factory presets, and the other half is for user-
defined patches. This unit must be tuned to the instrument you are
using, and offers pitch shifting in any of the modes. I believe it
produces up to three or more harmonics around the input. There are
notes on the IPS33 in the guitar notes files, and possibly in the
Music notes as well. An Eventide unit with comparable features
(like midi) sells for around $5000. I'm sure there are differances
in sound quality, construction, and circuitry, but the differance
in price is tremendous (let's face it, most people would be wasting
their time looking at an Eventide, unless they plan to sell their
car to get one, but the Digitech unit is quite affordable).
Some of the multi-effects units include a harmonizer. The A.R.T.
multiverb is one of their newer units that allows layering, and
includes a simple but useable pitch shifter which allows you to
produce one harmonic anywhere between -1 octave to +1 octave.
I believe the Yamaha SPX90 also allows for pitch shifting.
While these units may have usable pitch shifters, the IPS33
really blows them away.
Check one out !
Mark
|
| 60.11 | | ANT::JANZEN | cf. ANT::CIRCUITS,ANT::UWAVES | Wed Aug 09 1989 11:25 | 34 |
| > < Note 60.10 by ANT::JACQUES >
> -< Digitech IPS33 intelligent pitch shifter >-
>
> One harmonizer that was not mentioned (and is perhsps the best all
> produces up to three or more harmonics around the input. There are
If they are around the note in ratios other than positive integers,
they are not harmonics.
> notes on the IPS33 in the guitar notes files, and possibly in the
> Music notes as well. An Eventide unit with comparable features
> (like midi) sells for around $5000. I'm sure there are differances
> in sound quality, construction, and circuitry, but the differance
> in price is tremendous
It is my suspicion that modern VLSI digital signal processors and DACs
and ADCs are the same parts in most systems, especially the 32000
series DSP chips, and information about DSP s/w is common now, so
I wouldn't expect serious differences for this type of unit costing
thousands; after all, it's less software than a microcomputer and
less hardware as well.
> I believe the Yamaha SPX90 also allows for pitch shifting.
The SPX90 can pitch shift to one or two pitches simultaneously, with
feedback if desired, and delay to 2 seconds on the spx90II. Using
MIDI input changes the base note.
In practice this would allow a sequencer to play it any interval
you wanted in real time.
Sounds like a smart-shift function if you combine the
right hardware.
It shifts +/- 1 octave.
> Mark
Tom
|
| 60.12 | all you need is a harmonizer | UNXA::LEGA | Bug Busters Incorporated | Wed Aug 09 1989 11:39 | 13 |
| I know this is slightly off the track, but its notes-worthy.
When I was in high school, my friends sister worked with Larry
Fast's (solo albums, foreigner, p. gabriel) wife. Anyway,
Larry Fast was at my friends house for a picnic, and I was
gaping-mouthed in awe, and talked about keyboards.
(My setup at the time was a PAIA organtua, and a CAT-SRM synth)
He swore to me that the ONLY effect one ever needs is a harmonizer.
(he had an eventide)
Not that I believe him ((I think he has a fairlight or two now))
but at the time the words were divine.
|
| 60.13 | More on IPS | DREGS::BLICKSTEIN | Conliberative | Wed Aug 09 1989 11:49 | 38 |
| I'm normally not in to making corrects but some of these are
significant:
> I believe it produces up to three or more harmonics around the input.
I'm not sure what you meant by "up to 3 or more", but the IPS
is capable of producing two other pitches besides the original
pitch.
> An Eventide unit with comparable features (like midi) sells for
> around $5000.
I'm not sure which unit you are thinking of but the Eventide H-3000
is also comparable to the IPS-33 and sells for around $2,000.
(IPS sells for around $600-$700 as Mark stated.)
The H-3000 is also capable of doing most standard digital effects besides
harmonization.
The Eventide is definitely a higher quality unit, but the IPS-33
is remarkable for its price. I can't imagine too many people in
here springing the extra $1500 for the Eventide unless you have
a very serious studio.
I've played with the IPS-33. It tracks most keyboard patches
flawlessly. As for guitar, if you have good technique (you articulate
each note well), it will also track nearly flawlessly. If your
technique is not so good, you'll have problems.
Only crticism is that it's very sensitive to tuning. Your guitar
being slightly out of tune, or if you bend the string accidently
you will get very obvious and undesirable glitches.
I wrote a very extensive review in GUITAR (conference) somehwere.
It's definitely a hot unit.
db
|