[sdiy] sn76477 external control

[Dave Magnuson]

You need to be cautious when running between GND/V-.  You'd need to be sure
that your CVs (and other inputs) are inverted so they are always between
V-/GND.... if you send a positive input, it'll exceed the max operating
range of the chip.

I suggest you chek Rene Schmitz's design for the 566 VCO for ideas of how
he accomplished this.

http://www.uni-bonn.de/~uzs159/

Hopefully this will get you headed in the right direction




At 04:28 PM 5/29/02 +0200, Rude 66 wrote:
>that may be wordt a try if it doesn't destroy the synth.could it?
>
> the half octave range (and playing backwards,remember..) doesn't bother me
>too much because it's basically a noise box, and i can always sample a sound
>and then play it. it's not my only synth.. though 1 or 2 octaves would be
>cool. but it has 3 switches controlling range (sort of 'lo, mid, hi') so in
>reality the problem is probably there, as in the cv-in only controls the
>selected range, not the whole possible range. i've tried selecting all 3
>together, but that doesn't make it better either..;-)
>
>r./
>
>
>
>
>----- Original Message -----
>From: "Dave Magnuson" <resfreq at hoohahrecords.com>
>To: "Rude 66" <r.lekx at chello.nl>
>Cc: <synth-diy at dropmix.xs4all.nl>
>Sent: Wednesday, May 29, 2002 2:56 AM
>Subject: Re: [sdiy] sn76477 external control
>
>
>> The SN76477 is a single-supply chip, right?  Someone figured out you can
>> get more range/linearity from a 566 VCO by powering it between GND/V-
>> instead of V+/GND.
>>
>> Perhaps the same can be done here?  A half octave would KILL me.
>>
>> Dave
>>
>> At 01:53 AM 5/29/02 +0200, Rude 66 wrote:
>> >thanks! those articles included some good ideas.. it turned out to be as
>> >easy as soldering pin 16 to an external jack input for the cv. it's now
>> >happily chugging away arpeggios. also kinda found my gate mode again.. so
>> >even no need for external machines. i am happy, though it has a range of
>> >about 1/2 octave through external cv, and it's backwards too. maybe it's
>> >compatible to the kawai 100f..:)
>> >anyway, i can finally start with those sicker than sick basslines i've
>heard
>> >this thing play in my mind..
>> >
>> >r./
>> >
>> >
>> >
>> >----- Original Message -----
>> >From: "Ullrich Peter" <peter.ullrich at kapsch.net>
>> >To: "Rude 66 " <r.lekx at chello.nl>
>> >Cc: <synth-diy at dropmix.xs4all.nl>
>> >Sent: Tuesday, May 28, 2002 8:52 PM
>> >Subject: RE: [sdiy] sn76477 external control
>> >
>> >
>> >Hallo!
>> >
>> >>the only thing i haven't quite figured out is the external control. when
>> >>i first got it, it reacted to my mono/poly's arpeggiator, doing gate and
>> >>limited pitch. it has inputs for that, which don't seem to be working
>> >>naymore.
>> >>since this is basically someone else's project, it's kinda hard to
>> >>figure out what does what. does anyone know how to add especially cv-in
>to
>> >>the
>> >master oscillator? to gate it i can always run it through another
>> >>synth,but some kind of external pitch control would be nice.
>> >
>> >Have a look at the articles with the SN76477 on my homepage
>> >http://www.ullrich.at.tt !!!
>> >
>> >Switch to English if you want / then Music / and then click on my old
>> >SN76477
>> >synth near the bottom of the page. There is also a project with a
>keyboard!
>> >
>> >Ciao
>> >Peter
>> >
>> >http://www.ullrich.at.tt
>> >
>> >
>>
>> Resonant Frequency:
>> resfreq at hoohahrecords.com
>> http://www.hoohahrecords.com/resfreq/index.html
>
>

Resonant Frequency:
resfreq at hoohahrecords.com
http://www.hoohahrecords.com/resfreq/index.html