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Thread

Thinking on Mixer

1999-10-30 by Elhardt@xxx.xxx

It was my understanding from months back that one of the reasons for this
list was for user input on what features a module might have before Paul
designs it. Even though I am new to this list, it seems like some modules
are kept somewhat in the dark until after their specs are already pretty much
finalized or until their release. As with the Mixer, it is known to be a
dual 3:1 or single 6:1. But are there only two output connectors? Looking
at the Polyfusion mixer, I noticed they also provide inverted output so the
mixer can act as a voltage inverter also. (With no inverted output on the
LFO and no Inverter module, how can one do 180 degree out of phase stuff?).
They also duplicated the output connectors which helps reduce the use of
multiples if needed. Aries provides a combined mix output (mixed output from
two separate submixers), this would mean the MOTM would not have to be
switched between modes and leave a non functioning knob as some people stated
before. You would just pick the output connectors you wanted to use (A mix, B
mix or A+B mix). However you would need to rotate both output knobs to
adjust all 6 inputs to output levels if using it as a 6:1 input mixer. Just
wondering if total specs are made public before laying out the PCB and it is
too late for changes/additions?

-Elhardt

Re: Thinking on Mixer

1999-10-30 by J. Larry Hendry

> From: Elhardt@...
>
> It was my understanding from months back that one of the reasons for this

> list was for user input on what features a module might have before Paul
> designs it. Even though I am new to this list, it seems like some

modules

> are kept somewhat in the dark until after their specs are already pretty

much

Show quoted textHide quoted text

> finalized or until their release. As with the Mixer, it is known to be a

Snip, you must have joined the list after the two week 200 e-mail
discussion on mixers. We had ideas tossed from every direction. At one
time, it could have been 5U wide. HAHA. I think "this" mixer is supposed
to be more of a utility mixer for AC or DC.

Larry Hendry

Re: Thinking on Mixer

1999-10-30 by Paul Schreiber

Ken: check the archives! We had over 20 emails debating the mixer topology.

Basically, the splitting jack turns out to be the best, because of *panel
space*
to keep the mixer in a 2U wide format.

As far as having inverted stuff: point well taken. That's why on CV inputs I
use
"reversing attenuators" when possible. This allows an inverted response.
Inverted
audio has no meaning, but you can play all sorts of tricks with inverted CV
sources.

Paul S.

-----Original Message-----
From: Elhardt@... <Elhardt@...>
To: motm@onelist.com <motm@onelist.com>
Date: Saturday, October 30, 1999 2:36 AM
Subject: [motm] Thinking on Mixer

>From: Elhardt@...
>
>It was my understanding from months back that one of the reasons for this
>list was for user input on what features a module might have before Paul
>designs it. Even though I am new to this list, it seems like some modules
>are kept somewhat in the dark until after their specs are already pretty

much

>finalized or until their release. As with the Mixer, it is known to be a
>dual 3:1 or single 6:1. But are there only two output connectors? Looking
>at the Polyfusion mixer, I noticed they also provide inverted output so the
>mixer can act as a voltage inverter also. (With no inverted output on the
>LFO and no Inverter module, how can one do 180 degree out of phase stuff?).
>They also duplicated the output connectors which helps reduce the use of
>multiples if needed. Aries provides a combined mix output (mixed output

from

>two separate submixers), this would mean the MOTM would not have to be
>switched between modes and leave a non functioning knob as some people

stated

>before. You would just pick the output connectors you wanted to use (A mix,

>mix or A+B mix). However you would need to rotate both output knobs to
>adjust all 6 inputs to output levels if using it as a 6:1 input mixer.

Just

>wondering if total specs are made public before laying out the PCB and it

>too late for changes/additions?
>
>-Elhardt
>
>>

RE: Thinking on Mixer

1999-10-30 by Dave Bradley

> From: Elhardt@...
>
> It was my understanding from months back that one of the reasons for this
> list was for user input on what features a module might have before Paul
> designs it. Even though I am new to this list, it seems like
> some modules
> are kept somewhat in the dark until after their specs are already
> pretty much
> finalized or until their release. As with the Mixer, it is known to be a
> dual 3:1 or single 6:1. But are there only two output
> connectors?

This particular module was debated at long length, but it was several months
ago.
8 jacks max in a 2U wide format = 6 input, 2 output for this particular
module.

Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...

Re: Thinking on Mixer

1999-10-30 by J. Larry Hendry

> From: "Paul Schreiber" <synth1@...>
>
> Ken: check the archives! We had over 20 emails debating the mixer

topology.

I could have sworn it was closer to 200. This one really got talked around
on two different occasions.

I remember back in the very first days when we were actually having
discussions about 1/4 phone verses 1/8" verses banana, and what kind of
knobs, etc.

I saved a bunch of that stuff along with some of Paul's early notes about
what modules would be like. I think it is interesting to see how much
things have migrated and improved and to see that customer input really has
been considered along much of the design process.

Let's face it, we all have differing opinions, but Paul has to make the
final decisions after hearing all there is to hear. Some things I would
have done a little different for my personal taste on some of the modules.
But a couple of things I would not change are:

1. The value of this discussion group and what I have learned from everyone
here.
2. The quality of the stuff Paul puts into these things.

Larry (happy that the modules have input from others than me... he he)
Hendry

Re: Thinking on Mixer

1999-10-31 by Elhardt@xxx.xxx

jlarryh@... writes:

>>Snip, you must have joined the list after the two week 200 e-mail

discussion on mixers. We had ideas tossed from every direction.<<

You're right, I missed the big dicussion. My comment about being in the dark
about some yet to be released modules was not necessarily only about the
mixer. I guess I was also thinking about the new Low Pass Filter of which
there is little info, and when Paul made mention of a surprise (module I
guess?) to also be released. But I may have missed big discussions of those
also. If so, ignore my ranting.

Show quoted textHide quoted text

>>I remember back in the very first days when we were actually having

discussions about 1/4 phone verses 1/8" verses banana, and what kind of
knobs, etc. Let's face it, we all have differing opinions, but Paul has to
make the final decisions after hearing all there is to hear. Some things I
would have done a little different for my personal taste on some of the
modules.<<

I think he pretty much made the right decisions myself. No goofy wiggly blue
water patterns, no Celtic or floral wallpaper designs, no flourescent paint
splatters or African art to mess up the modules. Everytime I hear banana
plugs mentioned in conjunction with modulars, I cringe. When I heard a
reviewer of the Fenix semi-modular say that the banana plugs fit so nice and
firmly that he could practically lift up the entire synth by one patch cord,
I thought why the hell would I want to fight with plugging and unplugging
cables like that all day. And how attractive to have a protruding eight inch
stack of banana plugs sticking out of my modular. Don't get me started.
(Someone who with two fistfulls, pulls out 20 cables at once on his D**pher
modular, and they pop right out. They're like butter.)

The only thing I might have suggested was that all the modules don't
necessarily have to adhere rigidly to the patch matrix at the bottom of each
module. Sometimes being able to put connectors elsewhere can help the visual
flow of a module and allow more ways to lay out a module. The future
VC-DADSR comes to mind in a past discussion with someone. 5 knobs vertically
doesn't allow room for connectors. 5 knobs horizontally is wider than needed
just to stick to the current rigid design.

-Elhardt

Re: Thinking on Mixer

1999-10-31 by DAVEVOSH@xxx.xxx

In a message dated 99-10-30 23:06:13 EDT, you write:

<< Fenix semi-modular >>

never heard of this one ? is it still around? do they have a website? mostly
just idle curiousity.
thanks!
best,
dave

Re: Thinking on Mixer

1999-10-31 by J. Larry Hendry

> You're right, I missed the big dicussion. My comment about being in the

dark

> about some yet to be released modules was not necessarily only about the
> mixer. I guess I was also thinking about the new Low Pass Filter of

which

> there is little info, and when Paul made mention of a surprise (module I
> guess?) to also be released. But I may have missed big discussions of

those

> also. If so, ignore my ranting.

Ranting is always allowed and encouraged here. Heck, lots of good ideas
come from "challenging conventional wisdom", as they say where I work. I
don't think you missed anything on the MOTM-400 or surprise module. I
wrote Paul and told him I though the surprise module should be able to make
any complex patch on the MOTM system automatically 16 note polyphonic. So,
I'm sure that's what it will be. he he

> I think he pretty much made the right decisions myself. No goofy wiggly

blue

> water patterns, no Celtic or floral wallpaper designs, no flourescent

paint

> splatters or African art to mess up the modules. Everytime I hear banana

> plugs mentioned in conjunction with modulars, I cringe.

Well, some people like bananas. But, I share your view and was one voting
for 1/4"

> The only thing I might have suggested was that all the modules don't
> necessarily have to adhere rigidly to the patch matrix at the bottom of

each

> module. Sometimes being able to put connectors elsewhere can help the

visual

> flow of a module and allow more ways to lay out a module. The future
> VC-DADSR comes to mind in a past discussion with someone. 5 knobs

vertically

> doesn't allow room for connectors. 5 knobs horizontally is wider than

needed

Show quoted textHide quoted text

> just to stick to the current rigid design.

Well, there's an area where my opinion would (respectfully) disagree with
yours. I really like the fact that the patch points are always at the
bottom. In my opinion, you will never see 5 full size knobs vertically on
a standard MOTM panel. Paul's idea was to get as many of the pots as
possible on the board to save outboard wiring (I certainly appreciate
that). You could put 5 in a row and move the jacks elsewhere, but that
could require:

1. another different size mounting bracket
2. studs on the back of the panel in a different location
3. custom engineering of each layout starting from scratch

I'm sure Paul could add to that list. But, the bottom line is that all of
these things would add cost. Being able to use only one of the two current
bracket designs (full and half size), and starting a panel design from a
set standard speeds the process and lowers cost. So, from a pure
engineering point of view, that is one of the best ways to hold down cost
without compromising on the quality of parts. True, there are some
limitations imposed by that standardization.

Concerning no input on some of the modules, that is somewhat true. The
upcoming JH filter is a proven design clone of the popular filter from the
P5 I think. JH thought enough of the IC version to invest his time in a
discrete version. I am certain I could not contribute anything significant
to his well thought out circuit. Now the surprise module.... Well. I
guess we are ALL in the dark on that one. I am hoping it is another PS/JH
collaboration like the scanner. And, I hope it is NOT the Blacet/PS
collaboration of Dark Star in a MOTM format. But, whatever, I know it will
meet the same quality standards as all MOTM products.

Just to give you a couple of examples where user input has actually changed
a design even AFTER the initial issue:

MOTM-800 - The new one has a circuit addition which will allow full ADSR
operation with a gate only. That change was a direct response to ranting
(like yours) here on the list.

MOTM-100 - The new 101 will have a change to reduce popping during certain
conditions and I "think" a switch to replace the vibrato jumper that
everyone bitched about on the circuit board.

So, RANT away. It is a good thing. Sometimes when the ideas serve the
best interest of most users, they do make their way into design. However,
what goes along with the ranting process is realizing that lots of ideas
(especially mine) turn out to be not exactly the "best" for everyone.

Like all good investments, ranting takes time to mature. I think you will
see the fruits of that investment here over time. I wonder what Rex (that
other modular) would say if you called him up and wanted to change a few of
his designs for your purchase. (he he) I think we all know the answer to
that.

Larry (ranting, whining, p**sing & moaning or whatever it takes) Hendry

Re: Thinking on Mixer

1999-10-31 by DAVEVOSH@xxx.xxx

In a message dated 99-10-30 23:53:55 EDT, you write:

<< I wonder what Rex (that
other modular) would say if you called him up and wanted to change a few of
his designs for your purchase >>

larry,
i can`t comment on rex as i don`t know him but back in `78 when getting my
s**** from serge t. i was also getting a pitch to voltage converter from carl
fravel at gentle electric. at my urging, "s" talked to "c" and the result was
a pvc in the s**** module format. carl was also building an analog delay
module for me with a lot of v.c. functions and he sent my module to "s" to
see before it came to me. i think they came to an arrangement as "s" came out
with an analog delay module having most of those features a while later. so,
there are cases where talking to the designers can make a difference. another
point would be that i had asked "s" about changes to some modules and he sent
me back a few pages of modified schematics showing me where to make some of
the changes i was suggesting in the modules i had. it is a nice thing when
the designers want our input and try to help. from what i`ve read on this
list so far, paul seems to be this sort of interested type.
best,
dave

Re: Thinking on Mixer

1999-10-31 by Elhardt@xxx.xxx

jlarryh@... writes:

>>....the fact that the patch points are always at the bottom. So, from a

pure engineering point of view, that is one of the best ways to hold down
cost without compromising on the quality of parts. True, there are some
limitations imposed by that standardization.<<

Since I still haven't gotten my shipment of MOTM modules, I don't know
anything about the mechanical design behind the panel. So I am speaking not
having those considerations in mind. But those cost factors of course have
to come into the equation.

>>Concerning no input on some of the modules, that is somewhat true. The

upcoming JH filter is a proven design clone of the popular filter from the P5
I think.<<

It wouldn't be the actual filter design that would be discussed on something
like that. But maybe for example, the number of audio/modulation inputs or
other features outside of the actual filter circuit. If it is like the 420
filter in that area, then great.

Show quoted textHide quoted text

>>Just to give you a couple of examples where user input has actually changed

a design even AFTER the initial issue: MOTM-800 - The new one has a circuit
addition which will allow full ADSR operation with a gate only. That change
was a direct response to ranting (like yours) here on the list.<<

I would hope the 800 could be controlled with gate only like all other EGs,
because that is all that is usually available. That is why we should know
before final design.

-Elhardt

Re: Thinking on Mixer

1999-10-31 by J. Larry Hendry

That's great. I think now "s" and "c" are gone and "r" is building from
the old plans. BTW, this was not supposed to be an attack on "r." I spoke
to "r" once and he was a really nice guy and sent me a book simply on my
word to pay. Don't ever expect him to answer e-mail though.
LH

> From: DAVEVOSH@...
> larry,
> i can`t comment on rex as i don`t know him but back in `78 when getting

> s**** from serge t. i was also getting a pitch to voltage converter from

carl

> fravel at gentle electric. at my urging, "s" talked to "c" and the result

was

> a pvc in the s**** module format. carl was also building an analog delay
> module for me with a lot of v.c. functions and he sent my module to "s"

> see before it came to me. i think they came to an arrangement as "s" came

out

> with an analog delay module having most of those features a while later.

so,

> there are cases where talking to the designers can make a difference.

another

> point would be that i had asked "s" about changes to some modules and he

sent

> me back a few pages of modified schematics showing me where to make some

> the changes i was suggesting in the modules i had. it is a nice thing

when

Show quoted textHide quoted text

> the designers want our input and try to help. from what i`ve read on this

> list so far, paul seems to be this sort of interested type.
> best,
> dave

Re: Thinking on Mixer

1999-10-31 by DAVEVOSH@xxx.xxx

In a message dated 99-10-31 00:37:31 EDT, you write:

<< think now "s" and "c" are gone and "r" is building from
the old plans. BTW, this was not supposed to be an attack on "r." >>

larry,
i certainly didn`t take it that way and,like i said, i don`t know him. last i
heard, "s" moved to france. "c" seems to have disappeared. one of the people
who used to work with him was at emu at one time ( kevin monahan) but i don`t
know what became of him now either. i recall seeing that rex ran out of the
potted modules that made up the pitch to voltage converter. pity, it was a
fun module to mess around with and it worked pretty well. from a lengthy
article i saw in an old electronotes designing one that worked well was not a
simple engineering task!!! makes me wonder how well the pitch to midi gizmo`s
i`ve seen mentioned work -? anyone have one -? probably too specialized for
paul to mess with. me, i`d encourage weird waveshapers of all sorts but thats
just my two cents worth. once a workable basic set of modules is done, it is
the unusual ones that helps define a systems personality. me, i`m a heretic -
i pretty much think basic vco`s,vca`s,eg`s are "solved" problems due to
things like cem chips. its what is added to that foundation that makes the
difference and lets a designer focus on other, weirder things. IMHO, of
course, so please don`t shoot me!!!! :^)
best,
dave

Re: Thinking on Mixer

1999-10-31 by The Old Crow

On Sun, 31 Oct 1999 DAVEVOSH@... wrote:

> i pretty much think basic vco`s,vca`s,eg`s are "solved" problems due to
> things like cem chips. its what is added to that foundation that makes the
> difference and lets a designer focus on other, weirder things. IMHO, of

The thing is, to make the esoteric modules like waveform skewing modules
pay off is to start with *good* basics. A CEM3340 VCO is a nice device,
yes. Short of buying some of Paul's stock of the long-since-discontinued
chip and making your own VCO, or buying that module from some nondescript
German outfit that has limited quantity due to the same scarcity of
chips, or even digging up some old module's design on the web that used
the 3340--eventually this is going to stop being viable as the chips will
be depleted. (I have 16 of them sitting in a drawer that will never be
used because my Voytra-Eights use them, and I *must* stock repair parts
for those machines).

This is why modules like the MOTM-300 exist. A really good VCO that
*does not depend on some critical part that is no longer made*. Yes,
folks said the same thing when the uA726 went away. But other matched
pairs existed--not the case for a custom IC. In addition, to offer a
modular system means to effectively offer a *complete solution*, not just
nifty modules to fill in the gaps between "stuff I already have".

(Of course, I like VCOs. Lots of VCOs. ;)

--Crow

/**/

Re: Thinking on Mixer

1999-10-31 by DAVEVOSH@xxx.xxx

In a message dated 99-10-31 02:25:04 EST, you write:

<< long-since-discontinued
chip >>

i had been under the impression that there was a current producer of the
chips. if not, point taken.
a solid foundation of the "basics" is needed to be able to more fully exploit
the abilities of the more "exotic" modules, i certainly agree there also.
certainly, designing a good vco from scratch is not a trivial endevour but at
least there is a substancial body of existing work / literature to build upon.
a lot is subjective, too, on modulars. for example, i`m still learning the
"personality" of mine. its been pretty balanced, i find stuff i like, i find
stuff i don`t. here`s one most people don`t even think of - getting used to
"standard" adsr`s. i come from a background where the primary envelope
modules are ar`s. i`m used to combining envelopes to get more complex shapes.
basic adsr`s aren`t the same thing. not bad, just different. i`d love a nice,
complex envelope generator ( paul....... ).
i guess my point was to just try and encourage the design of modules that are
well outside the normal milieu.
best,
dave