MOTM

Hi All,

I like the Idea of the single master - this would be great from a
performance standpoint.
Perhaps the master control knob could be made larger than the others.

On another note, how many of us have broken the switches when installing?
I am a member in good standing of the "Switch Busters Club"

Mark Tencza

While attending a National Semi seminar today (Bob Pease was a riot! Had him
autograph his book)
I doodled out a mixer. Comments, please.

a) It's either 6:1 or 2 seperate 3:1 AC/DC mixers
b) in 6:1 mode, you have 2 outputs
c) in 3:1 mode, each mixer has an output
d) toggle switch that Larry torques to 400ft-lb selects the mode

now tricky stuff

e) there is only 1 MASTER level out. It is a dual pot. So, in 3:1 mode the
MASTER effects BOTH mixers
the same.

Actually, this can be sort of cool. You can still individually set the
levels (say Mixer #1 is "left" and Mixer #2 is "right")
and the with the MASTER fade them both in and out at once.

f) uses the pots found on the ADSR. I PROMISE to make the holes bigger this
time!!
g) uses OP275s as the summing amps, but a tricky OP-97 as a DC servo amp to
reduce the output
offset voltage to 25uV. This is so you can sum CV and audio with it and get
ZERO drift. As far as I know,
this has NEVER been done in any synth. Serge included.

I estimate the cost to be $130 because of the $$$ of the pots, it has 8
jacks, and the OP-97s ain't cheap.

Well??!?!?

Paul S.

Hi All !

Hmm, big real-estate problem . Would it be out of the question to
position the switch somewhere else (between knobs, maybe on the top)
so an extra pot could be accommodated for the second mix .

On another note, as the front hardware makes up most of the cost of
any module, how much would it be extra to VC each input . Not enough
real estate for this in 2U but 3U would do just fine .

The servo idea looks great .

Later .


Keep 'em oscillating :)


Hugo
=

> From: Paul Schreiber <synth1@...>
> While attending a National Semi seminar today (Bob Pease was a riot! Had

him

> autograph his book)
> I doodled out a mixer. Comments, please.
>
> a) It's either 6:1 or 2 seperate 3:1 AC/DC mixers
> b) in 6:1 mode, you have 2 outputs
> c) in 3:1 mode, each mixer has an output
> d) toggle switch that Larry torques to 400ft-lb selects the mode
>
> now tricky stuff
>
> e) there is only 1 MASTER level out. It is a dual pot. So, in 3:1 mode

the

> MASTER effects BOTH mixers
> the same.
>
> Actually, this can be sort of cool. You can still individually set the
> levels (say Mixer #1 is "left" and Mixer #2 is "right")
> and the with the MASTER fade them both in and out at once.

I like the sound of this. I do not consider the common master to be a
problem since there IS a master. The individual levels could be adjusted
on one channel if desired. could one side be AC while the other side was
DC? Would this cause the common master to be a heartache?

> f) uses the pots found on the ADSR. I PROMISE to make the holes bigger

this

> time!!

I personally liked the tight holes (don't we all)?

> g) uses OP275s as the summing amps, but a tricky OP-97 as a DC servo amp

to

> reduce the output
> offset voltage to 25uV. This is so you can sum CV and audio with it and

get

> ZERO drift. As far as I know,
> this has NEVER been done in any synth. Serge included.

If you say so Paul. This falls in that category for me of not knowing what
I want until Paul tells me <g>.

> I estimate the cost to be $130 because of the $$$ of the pots, it has 8
> jacks, and the OP-97s ain't cheap.
>
> Well??!?!?

I'll buy it.
Larry Hendry

DO IT!!!!!

Paul Schreiber wrote:

> From: "Paul Schreiber" <synth1@...>
>
> While attending a National Semi seminar today (Bob Pease was a riot! Had him
> autograph his book)
> I doodled out a mixer. Comments, please.
>
> a) It's either 6:1 or 2 seperate 3:1 AC/DC mixers
> b) in 6:1 mode, you have 2 outputs
> c) in 3:1 mode, each mixer has an output
> d) toggle switch that Larry torques to 400ft-lb selects the mode
>
> now tricky stuff
>
> e) there is only 1 MASTER level out. It is a dual pot. So, in 3:1 mode the
> MASTER effects BOTH mixers
> the same.
>
> Actually, this can be sort of cool. You can still individually set the
> levels (say Mixer #1 is "left" and Mixer #2 is "right")
> and the with the MASTER fade them both in and out at once.
>
> f) uses the pots found on the ADSR. I PROMISE to make the holes bigger this
> time!!
> g) uses OP275s as the summing amps, but a tricky OP-97 as a DC servo amp to
> reduce the output
> offset voltage to 25uV. This is so you can sum CV and audio with it and get
> ZERO drift. As far as I know,
> this has NEVER been done in any synth. Serge included.
>
> I estimate the cost to be $130 because of the $$$ of the pots, it has 8
> jacks, and the OP-97s ain't cheap.
>
> Well??!?!?
>
> Paul S.
>
> ------------------------------------------------------------------------
> Ideas on how we can improve ONElist?
> http://www.onelist.com
> Check out the Suggestion Box feature on our new web site

May as well get my 2 cents in...

>
> a) It's either 6:1 or 2 seperate 3:1 AC/DC mixers
> b) in 6:1 mode, you have 2 outputs
> c) in 3:1 mode, each mixer has an output
> d) toggle switch that Larry torques to 400ft-lb selects the mode
>
> now tricky stuff
>
> e) there is only 1 MASTER level out. It is a dual pot. So, in 3:1 mode the
> MASTER effects BOTH mixers
> the same.

How about this - 8 pots, 8 jacks, no switch. Configured as 2 3x1 mixers,
each with 3 input and 1 output level controls. Output of mixer 1 is
normalled to a hidden 4th summing node input on mixer 2 (no input jack or
pot). Plugging a jack into output 1 disconnects the normalling and you have
2 3x1 mixers. Use only output 2, and you have 1 6x1 mixer. You might need a
pulldown resistor on the hidden input so that it doesn't flop around when it
is disconnected. Does this sound feasible?

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

1) That's a s***tload of wiring
2) I am worried about confusion of having 2 LEVEL pots in 6:1 mode

Paul S.

-----Original Message-----
From: Dave Bradley <daveb@...>
To: motm@onelist.com <motm@onelist.com>
Date: Wednesday, March 10, 1999 10:14 AM
Subject: [motm] Re: Mixer idea

>From: "Dave Bradley" <daveb@...>
>
>May as well get my 2 cents in...
>
>>
>> a) It's either 6:1 or 2 seperate 3:1 AC/DC mixers
>> b) in 6:1 mode, you have 2 outputs
>> c) in 3:1 mode, each mixer has an output
>> d) toggle switch that Larry torques to 400ft-lb selects the mode
>>
>> now tricky stuff
>>
>> e) there is only 1 MASTER level out. It is a dual pot. So, in 3:1 mode

the

>> MASTER effects BOTH mixers
>> the same.
>
>How about this - 8 pots, 8 jacks, no switch. Configured as 2 3x1 mixers,
>each with 3 input and 1 output level controls. Output of mixer 1 is
>normalled to a hidden 4th summing node input on mixer 2 (no input jack or
>pot). Plugging a jack into output 1 disconnects the normalling and you have
>2 3x1 mixers. Use only output 2, and you have 1 6x1 mixer. You might need a
>pulldown resistor on the hidden input so that it doesn't flop around when

it

>is disconnected. Does this sound feasible?
>
>Dave Bradley
>Principal Software Engineer
>Engineering Animation, Inc.
>daveb@...
>
>
>------------------------------------------------------------------------
>New hobbies? New curiosities? New enthusiasms?
>http://www.onelist.com
>Sign up for a new email list today
>

> From: "Paul Schreiber" <synth1@...>
>
> 1) That's a s***tload of wiring

I guess I don't understand this. Isn't the only extra wiring over a straight
dual 3x1 mixer the 1 extra wire normalling them together?

> 2) I am worried about confusion of having 2 LEVEL pots in 6:1 mode

Ya got a point there. Maybe breaking the normalling could fire an analog
switch that grabs the mixer 1 output before the output pot, so that in 6x1
mode that pot just does nothing.

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

1) Sorry. I mean the amount of physical wiring versus what's on trace on the
pc board.

2) This violates the Prime Directive: All controls shall operate at all
times, else customer
thinks it's broken!

Paul S.

-----Original Message-----
From: Dave Bradley <daveb@...>
To: motm@onelist.com <motm@onelist.com>
Date: Wednesday, March 10, 1999 11:27 AM
Subject: [motm] Re: Mixer idea

>From: "Dave Bradley" <daveb@...>
>
>
>> From: "Paul Schreiber" <synth1@...>
>>
>> 1) That's a s***tload of wiring
>
>I guess I don't understand this. Isn't the only extra wiring over a

straight

>dual 3x1 mixer the 1 extra wire normalling them together?
>
>> 2) I am worried about confusion of having 2 LEVEL pots in 6:1 mode
>
>Ya got a point there. Maybe breaking the normalling could fire an analog
>switch that grabs the mixer 1 output before the output pot, so that in 6x1
>mode that pot just does nothing.
>
>Dave Bradley
>Principal Software Engineer
>Engineering Animation, Inc.
>daveb@...
>
>
>------------------------------------------------------------------------
>Have you visited our new web site?
>http://www.onelist.com
>Onelist: Helping to create Internet communities
>

> From: "Paul Schreiber" <synth1@...>
>
> 1) Sorry. I mean the amount of physical wiring versus what's on
> trace on the
> pc board.
>
> 2) This violates the Prime Directive: All controls shall operate at all
> times, else customer
> thinks it's broken!

OK, so when you plug in the jack, the pot retracts into the panel; you have
a specially made knob for it that collapses down to the size of the shaft.
That way, all VISIBLE controls operate at all times. Or, you could just grey
it out when it's not available (Windows joke).

Uh, never mind.

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

> From: "mmt" <mmt@...>
> On another note, how many of us have broken the switches when installing?
> I am a member in good standing of the "Switch Busters Club"
> Mark Tencza

The question is who holds the record for bustin' the most.
I nominate myself at 3.
Larry Hendry

> Dave Bradley wrote:
> OK, so when you plug in the jack, the pot retracts into the panel; you

have

> a specially made knob for it that collapses down to the size of the

shaft.

> That way, all VISIBLE controls operate at all times. Or, you could just

grey

> it out when it's not available (Windows joke).
> Uh, never mind.

OK, let me play this game. As much as I totally love both of Dave's
suggestions, I don't think they are practical. I am certain Paul could
design the retracting option. However, I am certain that I cannot afford
it. I don't like option # 2 because MOTM is one place in my electronics
that I don't want Bill Gates involved. <grin> Thanks for the humor Dave.

However, seriously, here is one more thought without specifying how it
would work (Paul figures that out)

8 jacks
8 pots
no 6:1 3:2 switch
Function is so that with only the A output plugged in it functions 6:1. But
with each master controlling the respective three it would for separate
operation. When B output is plugged in the masters separate into both A
and B outputs. So instead of a 6:1 or 3:2, It would really be a 3:2:1 or
3:2.

If this ideas sucks, don't blame me, I admit to not knowing anything.

One more thought and then I will shut up on the subject (I love this
process of idea sharing). How about if one of the master pots has a push
pull switch on the shaft. When you pull that knob out, it becomes disabled
as the second master and converts the mixer to 6:1. The violation of MOTM
rule that all controls must function is not resolved as "pull to disable
for 6:1" is a feature. Paul, can you find those swell pots with switches?
Even a rotary switch at the lower end of the operating range could have a
tick marked "6:1" or "disabled" or something cute. on the panel.

Larry Hendry

hi guy's.
i did not have time to read all this talk about the mixer desighn,i realy
dont mind for a 6:1 or ....
I WANT IT TO BE VC for all level and pan,i want a system with full vc on
each function.
would it be great to make a cv input for the switch pots on the 700 ?
would it be great to make cv for all of the 120 pots ?

i would agree to pay for it.
as more jacks the moduls would become more powerfull.

thanx
Gur Milstein

Hi All !

Since these are all low impedance/hi level signals one is mixing, how
about making two virtual summers, one with all 6 inputs and one with
say the last three . Give each mixer its output and pot . The six
vol pot would have a push switch that cuts off the last three inputs :

- pull : all six
- push : first three

An extra idea :

One could then normalise 1 to 4, 2 to 5 and 3 to 6 .

Tiny Matrix Mixer :) TMM (tm)

Hmm, this would halve the resistor value in 6 mode, maybe not such a
good idea...except when jack sockets with extra switches are used to
disconnect double inputs that is . Are these available in MOTM
quality, Paul ?

(Since the first hour i got my pc, i have not had a single grey day,
except for some programs that do not use all the desktop colours,
cause i made up my own ;-) )

Take care .


Keep 'em oscillating :)


Hugo
=