MOTM

If you are interested, go to

www.synthtech.com/pix

and look at the 2 MOTM-820 photos (I got a C- in Photography 101) and also,
there is a MS Word 97 copy of the manual! It is NOT proofread: feel free to
look for typos,
boo-boos, and other glitches. No schematic (feeling Serge-ish today).

It was actually COOL today in Texas. Yiippeee..

Paul S.

Hmmm, what can I use as a background for my 820 photo? I know, the
schematics!!!!

I'm just playing with ya' Paul! :)

Tony

> -----Original Message-----
> From: Paul Schreiber [mailto:synth1@...]
> Sent: Tuesday, September 26, 2000 9:45 PM
> To: MOTM listserv
> Subject: [motm] MOTM-820 stuff
>
>
> If you are interested, go to
>
> www.synthtech.com/pix
>
> and look at the 2 MOTM-820 photos (I got a C- in Photography 101)
> and also,
> there is a MS Word 97 copy of the manual! It is NOT proofread:
> feel free to
> look for typos,
> boo-boos, and other glitches. No schematic (feeling Serge-ish today).
>
> It was actually COOL today in Texas. Yiippeee..
>
> Paul S.
>
>
>
>
>
>
>

hello all
(my first attempt at sending to egroups from work...)

anyway, a couple of questions:
1)the application notes for the 820 imply that sticking an LFO into 
any of the CV inputs will cause some kind of HF noise when the LFO is 
in the negative part of its duty cycle, so how would be avoid this, 
or is there something already in there to stop this..?
2)how could i use a gate signal to switch the bypass in & out - or is 
this job for some kind of relay circuit (anyone fancy designing a 
simple module..?)
3) had to look - who is "dork" in the /pix directory..?

cheers
paul b
(hoping not to type all this out again tonight - but then if you 
never get this email then you wouldn't know that...)

> 1)the application notes for the 820 imply that sticking an LFO into
> any of the CV inputs will cause some kind of HF noise when the LFO is
> in the negative part of its duty cycle, so how would be avoid this,

Don't stick the output of the LFO into a '820 CV input would work.
But, you just need DC offset to avoid negative voltages. I think the
SAW out, with SHAPE around mid-range, will work. Check it on a 'scope.
This will make a 0-5V triangle.


> or is there something already in there to stop this..?

Nope.

> 2)how could i use a gate signal to switch the bypass in & out - or is
> this job for some kind of relay circuit (anyone fancy designing a
> simple module..?)

If the GATE does go to near ground (say, below 0.050V) then it should
BYPASS. I will test this out today and add a blurb to the manual. THe
pullup resistor is 2K7 to to +15V. So, you need to NOT hook it up to say TTL
outputs :) Moog S-Trig with pullup to +15V (an option of Kenton Pro-2000)
should work, as well as true open-collector outputs.


> 3) had to look - who is "dork" in the /pix directory..?

Err... that would be ME, circa 1978.

Paul S.

----- Original Message -----
From: Paul Schreiber <synth1@...>
It was actually COOL today in Texas. Yiippeee..

Indiana has been 40s night & 50s to upper 60s days as of late.  Heck, ther
trees are starting to turn.
Larry H

>>> Indiana has been 40s night & 50s to upper 60s days as of late.  Heck,
ther
trees are starting to turn. Larry H

Same here in Connecticut. I've had to run the furnace the past two nights
for the baby's sake.

>Indiana has been 40s night & 50s to upper 60s days as of late.

Nope, doesn't mean a thing to me. Halve it and add sixteen I think. But
here its raining and about 12C. :-)

Regards,

Tony Allgood  Penrith, Cumbria, England

Modular Synth:
www.techrepairs.freeserve.co.uk/projects.htm

hello all

> Don't stick the output of the LFO into a '820 CV input would work.
> But, you just need DC offset to avoid negative voltages. I think the
> SAW out, with SHAPE around mid-range, will work. Check it on a 'scope.
> This will make a 0-5V triangle.

a gasp escapes from somewhere near the back of my mind...
so the CV inputs should be triggered by EGs only then
it's just that i immediately thought it would be cool to stick a load of
LFOs into everything (my stock response to any box that has a "CV IN"

> > or is there something already in there to stop this..?
> Nope.
i couldn't do something with a diode over the control inputs could i...?
(ducking)

> If the GATE does go to near ground (say, below 0.050V) then it should
> BYPASS. I will test this out today and add a blurb to the manual. THe
> pullup resistor is 2K7 to to +15V. So, you need to NOT hook it up to say
TTL
> outputs :) Moog S-Trig with pullup to +15V (an option of Kenton Pro-2000)
> should work, as well as true open-collector outputs.

or a Korg S-Trig style 5V..? (that last sentence went right over my head
today)

> > 3) had to look - who is "dork" in the /pix directory..?
> Err... that would be ME, circa 1978.

that's nothing, i was only ten then, however at least i could blame my
parents for any fashion mistakes back then :)

cheers
paul b