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Re: [motm] MOTM DIY - Was: List OK?

Re: [motm] MOTM DIY - Was: List OK?

2000-06-28 by CHRIS PARKER

Hey Larry! I m glad to finally hear some MOTM traffic...it s been terribly dull at work lately!!! These modules sound interesting!  Is there any chance you

Re: [motm] MOTM DIY - Was: List OK?

2000-06-28 by J. Larry Hendry

Absolutely Chris. Sharing was the whole reason for making the post to begin with. I have nothing to sell. You have to buy protoboards from Paul if you want to copy my exact layout because that is what I use. ; My current copy of the schematic is rather scratched up from changes I made as I went along. So, I will need to re-draw it first. But, I have a paper version of the proto board showing all the jumpers installed and component placement that is free to anyone that wants it. Photos are also available.
Larry H
----- Original Message -----
I'm glad to finally hear some MOTM traffic...it's been terribly dull at work lately!!!
These modules sound interesting! Is there any chance you might share the schematics/wiring diagrams for these module(s) with those of us who might want to build a couple ourselves?

Re: [motm] MOTM DIY - Was: List OK?

2000-06-28 by davevosh@aol.com

In a message dated 00-06-28 12:00:59 EDT, you write:

<< The result is a 1U utility module with three rotary switches for interval
 selection and six 1/4 jacks (3 CV IN, 3 CV OUT).  Each interval switch can
 be used separately, or all outputs controlled by the same keyboard CV
 (normalled a to b, b, to c).  >>



larry,
while range switching and precise intervals aren`t really my conceptual "cup 
of tea", this does seem handy in general.....i could see using something like 
this for swithching filter ranges or something.  keep us posted on how 
version 2 develops.
best,
dave v.
p.s. - have a good vacation!

Re: [motm] MOTM DIY - Was: List OK?

2000-06-29 by Nathan Alan Hunsicker

I wonder how hard it would be modify a module like that to effect the
scaling not the offset. a module that could switch tracking on the fly
to control a filter (kinda like the moogs had 1/3, 2/3 and full) -Nate

"J. Larry Hendry" wrote:
Show quoted textHide quoted text
> ----- Original Message -----
> From: thomas white <djthomaswhite@...>
> I haven't got any MOTM list messages for some time now.
> Is the list OK or did I get dropped or something?
>
> ------------------
> Yes, Thomas, the list appears to be OK.  It is suffering from a case
> of
> "everybody doing something else" I guess.  Since the list is quiet and
> I
> cannot be therefore accused of hogging the bandwidth (something I am
> very
> good at), I will share my latest DIY addition to my MOTM system.  This
> is my
> second project to be completely finished into a final assembly on MOTM
>
> proto-board.  I am having so much fun doing this, I just ordered a
> "pile-o-proto boards" from Paul so I can do some more (utility type
> stuff).
>
> This module is a manually controlled pitch shifter.  I started to make
> this
> just an octave switch, as I wanted a way to shift octaves and maybe
> 5ths
> between my MOTM oscillators without having to retune them.  I just
> like
> having octave switches on an oscillator.  BUT, the MOTM-300's pot
> control
> offers more range and I did not want to even THINK about modifying the
>
> greatest oscillator module on the planet.  So, my original plan was to
> make
> a module that put out a selection of fixed voltages that could be
> connected
> to one of the FM inputs of the MOTM-300 to provide this feature (real
> simple
> stuff).  There was some discussion on the list.  However, Ken Tkacs
> twisted
> my arm around my back (a neat trick via e-mail) and told me my plan
> should
> be modified so that the 1 volt/oct voltage keyboard CV connects to my
> module, and then my module connects to the MOTM-300 or any 1 volt-oct
> VCO.
> After first dismissing this as too difficult for a guy with a business
>
> degree, I finally admitted Ken was right (like he almost always is
> BTW), and
> adopted his concept for my project.
>
> The result is a 1U utility module with three rotary switches for
> interval
> selection and six 1/4 jacks (3 CV IN, 3 CV OUT).  Each interval switch
> can
> be used separately, or all outputs controlled by the same keyboard CV
> (normalled a to b, b, to c).  This simple circuit adds the selected
> voltage
> interval to the incoming keyboard CV and that is the output.  This
> first
> version has 5 interval shifts up and 5 down.  There are three channels
> of
> shift.  The interval shift amount is completely "user selectable" by
> the
> fixed resistor selection in a corner or the circuit board (when
> building).
> I was going to use only octaves and 5ths.  But along the way with my
> experimenting, I found many other useful and interesting harmonics
> (Thanks
> Ken)
>
> So, you hook your keyboard CV to the input of the module.  You hook
> this
> module's CV outputs (3) to the 1-volt-oct inputs of your oscillators
> and
> tune all the oscillators in unison (at the high end of the CV range
> BTW).
> Then you can use the rotary switches to shift the intervals between
> oscillators.  Of course, one oscillator (your fundamental frequency)
> does
> not need to pass through this module.  I have the module constructed
> and
> tuned and it works quite well.
>
> Version # 2 of this module, will feature only 2 channels of shifting
> (yes,
> we can get by with 3 oscillators per voice).  However, it will have
> MUCH
> more shifting capability.  It will have 4 rotary switches and 4 jacks
> (2 CV
> IN and 2 CV OUT).  The difference is that ANY semitone interval is
> selectable.  Since each shift channel has 2 switches, one will select
> octaves up and one octaves down.  The other will select intervals in
> semitones +1 through +11.  So, no user interval choice will be
> required when
> building.  Version # 2 is layed out on paper proto board but will not
> be
> tested and functional for about a month.  I am taking a 2 week
> vacation to
> the Washington, Idaho, Montana and Calgary, Canada.  So, I will start
> constructing it when I get back.
>
> Obviously, these are simple circuits consisting of resistor voltage
> dividers
> for interval voltages and op amps for DC adding.  The trick has been
> getting
> the accuracy in the 1 volt/oct CV.  If anyone has any additional
> interest in
> either of these two utility modules, please e-mail me off list.  I
> don't
> want to turn the MOTM list into DIY discussion for the many that don't
>
> build.  However, since this is created in the MOTM format for use with
> MOTM,
> I wanted to share it with the list.
>
> Thanks to Ken Tkacs for his inspiration and to Paul for answering the
> one
> hundered stupid Stooge-like questions.
>
> Larry Hendry
>
> Disclaimer:  I am not a BS/MSEE.  I am not a design engineer.  This is
> DIY
> learning stuff.  My only claims are that:
> 1 - I am having fun
> 2 - My circuit works very well
> 3 - I am buying more MOTM proto boards than anyone else.
>
>
>
> -----------------------------------------------------------------------
>
> -----------------------------------------------------------------------
>

Re: [motm] MOTM DIY - Was: List OK?

2000-06-29 by J. Larry Hendry

If I understand what you are saying, that would be very easy.  On both the
420 and 440 you could put your tracking voltage into one of the FM inputs.
The FM attenuator would provide the tracking magnitude on the fly.
Certainly a switch could be constructed as you mention, but I would ask why?

Larry Hendry
Show quoted textHide quoted text
----- Original Message -----
From: Nathan Alan Hunsicker <nate@...>
To: <motm@egroups.com>
Sent: Wednesday, June 28, 2000 7:03 PM
Subject: Re: [motm] MOTM DIY - Was: List OK?


I wonder how hard it would be modify a module like that to effect the
scaling not the offset. a module that could switch tracking on the fly
to control a filter (kinda like the moogs had 1/3, 2/3 and full) -Nate

Re: [motm] MOTM DIY - Was: List OK?

2000-06-29 by Nathan Alan Hunsicker

I guess for the same reasons you wouldn't want to retune your
oscillators to a fifth or other interval while playing, it's just easier
to flip a switch on another module to get the desired tracking, plus it
still leaves you with 2 FM inputs. not a necessity more of  a
convenience. -Nate

"J. Larry Hendry" wrote:
Show quoted textHide quoted text
> If I understand what you are saying, that would be very easy.  On both
> the
> 420 and 440 you could put your tracking voltage into one of the FM
> inputs.
> The FM attenuator would provide the tracking magnitude on the fly.
> Certainly a switch could be constructed as you mention, but I would
> ask why?
>
> Larry Hendry
>
> ----- Original Message -----
> From: Nathan Alan Hunsicker <nate@...>
> To: <motm@egroups.com>
> Sent: Wednesday, June 28, 2000 7:03 PM
> Subject: Re: [motm] MOTM DIY - Was: List OK?
>
>
> I wonder how hard it would be modify a module like that to effect the
> scaling not the offset. a module that could switch tracking on the fly
>
> to control a filter (kinda like the moogs had 1/3, 2/3 and full) -Nate
>
>
>
>
> -----------------------------------------------------------------------
>
> -----------------------------------------------------------------------
>

Re: [motm] MOTM DIY - Was: List OK?

2000-06-29 by jwbarlow@aol.com

In a message dated 6/28/2000 5:02:45 PM, nate@... writes:

>I wonder how hard it would be modify a module like that to effect the
>scaling not the offset. a module that could switch tracking on the fly
>to control a filter (kinda like the moogs had 1/3, 2/3 and full) -Nate

Couldn't one just run the keyboard voltage through an attenuator and have a 
bypass switch for the straight keyboard voltage? I would use external knobs 
to set the scaling anyway (so that it could be adjusted for any particular 
ratio needed). Note: if you wanted ratios greater than one, you'd need to add 
at least one op amp (or similar active electronics).

Great work Larry -- you are obviously very happy with it. I can imagine this 
would be a real great module in a performance situation. I absolutely don't 
mind people posting the schematics, pictures, and descriptions of diy modules 
to the list (people who don't like it can just delete it). I think MOTM is a 
great diy platform for unusual modules, and sometimes these diy discussions 
could lead to developments in the MOTM line. And I don't see how anyone could 
complain with the list as slow as it's been for the past few days.

Sitting in almost no pain.
JB

Re: [motm] MOTM DIY - Was: List OK?

2000-06-29 by jhaible

> Couldn't one just run the keyboard voltage through an attenuator and have
a
> bypass switch for the straight keyboard voltage?

Yes.

And if you want a *really* cheap and dirty solution (I don't recommend
it, but sometimes quick and dirty is fine though it's clearly sub standard
...),
solder a cable with a 100k series resistor at one end (for 1/2 tracking).
Just make sure that the resistor end of the cable goes at the input of the
VCF,
not the output of the keyboard. Depending on your mechanical skill, you
can also solder a switch across this resistor.

JH.

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