Electronic Organ

[Rickydou]

Hello,

I need to find or design an Electronic Organ that would generate a full
octave sound (DO-RE-MI-FA-SOL-LA-SI-DO) depending on which switch we
press. Ideally an OEM module that could be intergrated in between our
switches and the amplifier would be the best.

Anywone would know where I could find this type of module or how to
design this module using standard component?

thank you very much!

Eric

 

[Luhan]

Hello,

I need to find or design an Electronic Organ that would generate a full
octave sound (DO-RE-MI-FA-SOL-LA-SI-DO) depending on which switch we
press. Ideally an OEM module that could be intergrated in between our
switches and the amplifier would be the best.

Anywone would know where I could find this type of module or how to
design this module using standard component?

thank you very much!

Eric

Sinewaves or complex waveforms?

Attack-Decay-Sustain-Release envelope?

Monophonic or Polyphonic (how many notes)?

Luhan

 

[Rickydou]

Hello Luhan,

I just need to produce simple tone, so I assume sinewave would be
enough... as for the envelope, you will have to excuse my musical
knowledge... I'm not sure what to answer you...

As for the number of notes, we would like to be able to play several
note at the same time.

Does it help you?

Thanks

Eric

 

[Luhan]

Hello Luhan,

I just need to produce simple tone, so I assume sinewave would be
enough... as for the envelope, you will have to excuse my musical
knowledge... I'm not sure what to answer you...

As for the number of notes, we would like to be able to play several
note at the same time.

Does it help you?

(please bottom post)

The simplest method may be a microcontroller making square waves. I
have gotten as many a 4 simultaneous notes out of a PIC - but you have
to do the programming.

Note producing systems are generally rated by the degree of polyphony -
how many notes you can have at the same time. There is usually no real
limit on the number of notes available.

Luhan

 

[JeffM]

I need to find

Eric (Rickydou)

Look in any toy store.
There's no need to re-invent the wheel for the billionth time.

or design an Electronic Organ

School assignment?
http://www.google.com/search?q=top-octave-generator&num=100

 

[Bob Eld]

Hello,

I need to find or design an Electronic Organ that would generate a full
octave sound (DO-RE-MI-FA-SOL-LA-SI-DO) depending on which switch we
press. Ideally an OEM module that could be intergrated in between our
switches and the amplifier would be the best.

Anywone would know where I could find this type of module or how to
design this module using standard component?

thank you very much!

Eric

Pick up a cheap synthesizer like a Casio. They have many voices and most
operate over four octaves or more. As was said above, don't re-invent the
wheel unless you want the exercise in programming a micro or something. BTW,
the eight note octave Do to Do is incomplete. A chromatic octave has 13
notes not eight. C, C#, D, D#, E, F, F#, G, G#, A, A#, B, C. If your octave
is not complete, you are very limited in key.
Bob

 

[Rich Grise]

Pick up a cheap synthesizer like a Casio. They have many voices and most
operate over four octaves or more. As was said above, don't re-invent the
wheel unless you want the exercise in programming a micro or something. BTW,
the eight note octave Do to Do is incomplete. A chromatic octave has 13
notes not eight. C, C#, D, D#, E, F, F#, G, G#, A, A#, B, C. If your octave
is not complete, you are very limited in key.
Bob

Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it. Each freq. is the lower one times the twelfth root of 2.

Cheers!
Rich

 

[[email protected]]

[...]

Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it.

Err... the octaves in a well-tempred scale *are* exact, it's the other
intervals that are approximations.

Anno

 

[Paul Burke]

[...]

Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it.

Err... the octaves in a well-tempred scale *are* exact, it's the other
intervals that are approximations.

Even temperament means that the ratio between successive semitones is
the twelfth root of 2, 0r about 1.0595. Only electronic instruments
really get tuned that way though. Piano tuners bend the tuning quite a
bit, particularly at the extreme ends of the keyboard.

Paul Burke

 

[Ken Smith]

Hello,

I need to find or design an Electronic Organ that would generate a full
octave sound (DO-RE-MI-FA-SOL-LA-SI-DO) depending on which switch we
press. Ideally an OEM module that could be intergrated in between our
switches and the amplifier would be the best.

Anywone would know where I could find this type of module or how to
design this module using standard component?

Many years back pop-tronics (I think it was) had a design that used NE-2s.
It only needed one RC and NE-2 per note. IIRC the signal was taken from
the common point of all the capacitors.

 

[Rich Grise]

[...]

Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it.

Err... the octaves in a well-tempred scale *are* exact, it's the other
intervals that are approximations.

OK, I misspoke. The _octave_ is a perfect octave, as you say, and it's the
other notes - maybe I should have said, "chromatic scale" instead of
"octave".

Thanks,
Rich

 

[Rickydou]

Thank you very much for helping me. You are right...I do not want to
re-invent the wheel!

I also found an IC that is specialized for this application: MOSTEK
MK50240 Top-Octave Frequency Generator. I just need to find a supplier
for this...

Thanks!

Eric

[...]

Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it.

Err... the octaves in a well-tempred scale *are* exact, it's the other
intervals that are approximations.

OK, I misspoke. The _octave_ is a perfect octave, as you say, and it's the
other notes - maybe I should have said, "chromatic scale" instead of
"octave".

Thanks,
Rich

 

[Michael A. Terrell]

Thank you very much for helping me. You are right...I do not want to
re-invent the wheel!

I also found an IC that is specialized for this application: MOSTEK
MK50240 Top-Octave Frequency Generator. I just need to find a supplier
for this...

Thanks!

Eric

Have you got a time machine?


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

 

[Don Lancaster]

Thank you very much for helping me. You are right...I do not want to
re-invent the wheel!

I also found an IC that is specialized for this application: MOSTEK
MK50240 Top-Octave Frequency Generator. I just need to find a supplier
for this...

Thanks!

Eric

[...]


Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it.

Err... the octaves in a well-tempred scale *are* exact, it's the other
intervals that are approximations.

OK, I misspoke. The _octave_ is a perfect octave, as you say, and it's the
other notes - maybe I should have said, "chromatic scale" instead of
"octave".

Thanks,
Rich

The MK50240 is outrageously and horrendously obsolete.

Check the Ensoniq chips instead.

But the magic numbers appear in my CMOS and TTL cookbooks.
There is only ONE eight bit sequence that gets all of the notes right.





--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Michael Black]

Have you got a time machine?

Those things were so impressive when they were introduced, doing away
with a bunch of oscillators or at the very least an oscillator and
a bunch of small count digital counters. All you needed was an oscillator
of the right frequency, and you'd get an octave of notes all with the
exact ratio to the others that was required. More octaves were easy,
since it just required a string of flip flops per note (or a more
integrated string of them). Get that needed sawtooth to boot, with
summing resistors of the outputs of the flip flops.

But yes, things have leaped further since then. Last week, I found
a small Casio "synthesizer" on a pile of garbage, sadly one black
key is broken, which I intend to give to a one year old when he's
a tad older. This is twenty or so years old, likely cost a fair
amount when new, but they were doing polyphonic in that thing with
a single IC (so I hear, I've not opened up), I think a CPU.

It's gotten so easy that every computer basically has a full synthesizer
built in, and top octave dividers are long in the past.

Michael

 

[Michael Black]

Thank you very much for helping me. You are right...I do not want to
re-invent the wheel!

I also found an IC that is specialized for this application: MOSTEK
MK50240 Top-Octave Frequency Generator. I just need to find a supplier
for this...

Thanks!

Eric

On Fri, 07 Jul 2006 10:43:15 +0000, anno4000 wrote:



[...]


Strictly speaking, the "well-tempered" scale is one that's not an exact
chromatic octave in any key, but "close enough" in _every_ key to get away
with it.

Err... the octaves in a well-tempred scale *are* exact, it's the other
intervals that are approximations.


OK, I misspoke. The _octave_ is a perfect octave, as you say, and it's the
other notes - maybe I should have said, "chromatic scale" instead of
"octave".

Thanks,
Rich

The MK50240 is outrageously and horrendously obsolete.

Check the Ensoniq chips instead.

But the magic numbers appear in my CMOS and TTL cookbooks.
There is only ONE eight bit sequence that gets all of the notes right.

Don't forget all your articles in Popular Electronics where you explained
the insides of a synthesizer, about when top-octave dividers were the
cat's meow, a big step forward from analog synthesizers, but only
a small step in terms of what came later.

Michael

 

[JeffM]

Get that needed sawtooth to boot,

with summing resistors of the outputs of the flip flops.
Michael Black

<nit-pick>
The wave shaping is actually done on the far side of the key contacts.
</nit-pick>

(This requires only 1 key contact per rank per key.)

 

[Glenn Gundlach]

Those things were so impressive when they were introduced, doing away
with a bunch of oscillators or at the very least an oscillator and
a bunch of small count digital counters. All you needed was an oscillator
of the right frequency, and you'd get an octave of notes all with the
exact ratio to the others that was required. More octaves were easy,
since it just required a string of flip flops per note (or a more
integrated string of them). Get that needed sawtooth to boot, with
summing resistors of the outputs of the flip flops.

But yes, things have leaped further since then. Last week, I found
a small Casio "synthesizer" on a pile of garbage, sadly one black
key is broken, which I intend to give to a one year old when he's
a tad older. This is twenty or so years old, likely cost a fair
amount when new, but they were doing polyphonic in that thing with
a single IC (so I hear, I've not opened up), I think a CPU.

It's gotten so easy that every computer basically has a full synthesizer
built in, and top octave dividers are long in the past.

Michael

Musically, the 50240 was an 'improvement' over 12 discrete out-of tune
oscillators but it was not good. The intervals were all over the place,
some notes sharp and others flat -- musically unpleasant. I replaced
one with a raft of 74F chips running at 32 MHz instead of 2 MHz which
managed to cross the boundary between 'appliance' and 'instrument'.

I bought some organ samples from Milan Digital audio and re-sampled
(tuned) using CoolEdit. You can hear an example here.

http://www.milandigitalaudio.com/buzard12demos.htm

GG

 

[Don Lancaster]

<nit-pick>
The wave shaping is actually done on the far side of the key contacts.
</nit-pick>

(This requires only 1 key contact per rank per key.)

Not any more.

All the keys are scanned into a standard xy keyboard matrice.


--
Many thanks,

Don Lancaster voice phone: (928)428-4073
Synergetics 3860 West First Street Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml email: [email protected]

Please visit my GURU's LAIR web site at http://www.tinaja.com

 

[Michael Black]

Not any more.

All the keys are scanned into a standard xy keyboard matrice.

Obviously it's all done differently now.

But even in your CMOS Cookbook, and your article in Popular Electronics
that showed the basics of a polyphonic synthesizer using the top octave
divider, you show ramps going to the VCAs, and those ramps were generated
by summing the outputs of the ripple counters at the outputs of the top
octave divider.

And, a page of my copy of the CMOS Cookbook just fell out, 29 years
after I got the book. That's the first of your books that have come
apart, though I admit I likely have taken more care of them than
some books. (On the other hand, the various TAB books I have have
never fallen apart, but they've seen far less use.)

Michael