[sdiy] sequential multitrack schematics.

[mark verbos]

what if you used a hi frequency triangle or saw wave to dither the CV, 
then you could get fading out of it. no?


Mark



harry bissell wrote:

> The ability to use CV to select waveforms is more to 'save' IC pins.
> 
> Its not real interesting to use the CV to switch dynamically... they don't
> MIX, they switch.  You could use a CV to program the chip (recall from 
> computer
> with one DAC and multiple S/H like uhhh... every CEM or SSM synth thta 
> ever was ?
> 
> Having a pot 'might' be useful... I'd suggest that a rotary switch or a 
> couple of toggles
> that produce the correct voltages might be a better interface. The pot 
> would be fussy
> and hard to mark the front panel... the switch points would probably not 
> be easy to label...
> no detents etc...
> 
> OTOH if you want to use an LFO to switch waveforms... then the pot would 
> offer a lot
> of variations and fine-tuning of sounds... its a ~feature~ then, not a 
> bug. Only building it
> will tell you for sure...
> 
> H^) harry
> 
> 
> Cole Groff wrote:
> 
>> So... physically, how would I select the waveshape if I were to have
>> this all laid out in front of me, on a front panel?
>>
>>
>>
>> On 9/26/06, harry bissell <harrybissell at prodigy.net> wrote:
>>
>>> Save you the trouble... the CV selects the waveform
>>>
>>> H^) harry
>>>
>>> Cole Groff wrote:
>>> > I'll contact the fellow who made the interface.
>>> >
>>> > Do you see down towards the bottom, the "Wave Select CV."  And then
>>> > farther down there is a 10K potentiometer.  I'm guessing the
>>> > potentiometer selects the wave?
>>> >
>>> > Cole
>>> >
>>> > On 9/26/06, Altitude <Altitude at optrand.com> wrote:
>>> >> Cole,
>>> >>   without looking at the data sheet for the 3394 (which you will
>>> >> probably
>>> >> need to do), I'll guess that it the CV is divided into 4 ranges which
>>> >> select
>>> >> the waveform
>>> >>
>>> >> -----Original Message-----
>>> >> From: owner-synth-diy at dropmix.xs4all.nl
>>> >> [mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of Cole Groff
>>> >> Sent: Tuesday, September 26, 2006 10:49 PM
>>> >> To: synth-diy at dropmix.xs4all.nl
>>> >> Subject: Re: [sdiy] sequential multitrack schematics.
>>> >>
>>> >> Thanks Raph.  This looks really nice.
>>> >>
>>> >> What I don't understand about this interface, is how it selects which
>>> >> wave
>>> >> form to use.
>>> >>
>>> >> How do you do this?
>>> >>
>>> >> Cole
>>> >>
>>> >> On 9/26/06, Altitude <Altitude at optrand.com> wrote:
>>> >> > No, its all analog goodness.
>>> >> >
>>> >> > Aaron Cram designed and interface for it for modular use:
>>> >> >
>>> >> > www.ori.org/~aaronc/synth/CEM3394_V2.pdf
>>> >> >
>>> >> > Don't go hacking apart a multitrak for parts if it still works, its
>>> >> > still a cool synth :P
>>> >> >
>>> >> > Cheers,
>>> >> > Raph
>>> >> >
>>> >> > -----Original Message-----
>>> >> > From: Cole Groff [mailto:chonald at gmail.com]
>>> >> > Sent: Tuesday, September 26, 2006 5:42 PM
>>> >> > To: Altitude
>>> >> > Subject: Re: [sdiy] sequential multitrack schematics.
>>> >> >
>>> >> > Does the CEM 3394 need a computer or microprocessor to control 
>>> it?  Or
>>> >> > can it be made into a synth module?
>>> >> >
>>> >> > On 9/26/06, Altitude <altitude at optrand.com> wrote:
>>> >> > > They were all socketed on mine
>>> >> > >
>>> >> > >
>>> >> > > __________________________________________
>>> >> > > "Setting the RESONANCE to high level might prove interesting" -
>>> >> > > Roland
>>> >> > > SH-101 Manual
>>> >> > >
>>> >> > > www.no-ho.com
>>> >> > > www.teknatural.com
>>> >> > >
>>> >> > >
>>> >> > >
>>> >> > > -----Original Message-----
>>> >> > > From: owner-synth-diy at dropmix.xs4all.nl
>>> >> > > [mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of Cole 
>>> Groff
>>> >> > > Sent: Tuesday, September 26, 2006 4:05 PM
>>> >> > > To: synth-diy at dropmix.xs4all.nl
>>> >> > > Subject: Re: [sdiy] sequential multitrack schematics.
>>> >> > >
>>> >> > > Thanks guys.
>>> >> > >
>>> >> > > On to my next questions:
>>> >> > > How hard will it be to remove these CEM chips from the SCI's 
>>> circiut
>>> >> > board?
>>> >> > >
>>> >> > > Are there any precautions I should take, or special things I
>>> >> should do?
>>> >> > >
>>> >> > > Cole
>>> >> > >
>>> >> > > On 9/26/06, Bob Weigel <sounddoctorin at imt.net> wrote:
>>> >> > > > These are a great sounding little machine.  Most compact 
>>> velocity
>>> >> > > > sensitive poly analog that I know of. And yes it uses the 
>>> CEM3394
>>> >> > > > as does six-trak, Split-eight (still have one for sale here but
>>> >> > > > it's so mint I'm waiting for the right buyer), and MAX as 
>>> well as
>>> >> > > > the Akai AX-60 and 73 as I recall.
>>> >> > > >
>>> >> > > > There is lots of info off my cu.imt.net/~sounddoctorin/synthtec
>>> >> page.
>>> >> > > > Just follow the logical links to SCI etc.  Also note that 
>>> there is
>>> >> > > > a design flaw in the machine which causes the battery to 
>>> discharge
>>> >> > > > in about a year and a half.  If you don't enjoy replacing
>>> >> > > > batteries I can show you how to fix that.  Much...pain 
>>> finding the
>>> >> problem.
>>> >> > > > Would never object to being tipped for the tip on that one.
>>> >> > > >
>>> >> > > > As far as I know there is no specific parameter edit on these
>>> >> > > > machines but patches are small so dumping a patch is probably
>>> >> how it's
>>> >> done.
>>> >> > -Bob
>>> >> > > >
>>> >> > > > Cole Groff wrote:
>>> >> > > >
>>> >> > > > > is there anywhere to find out what's inside a multitrack?  i
>>> >> > > > > might have the opportunity to buy one from a friend.  i 
>>> want to
>>> >> > > > > know what's in there.
>>> >> > > > >
>>> >> > > > >
>>> >> > > >
>>> >> > >
>>> >> > >
>>> >> >
>>> >> >
>>> >>
>>> >>
>>> >
>>> >
>>>
>>>
>>
>>
> 
>