Doepfer

Dieter,
 
that would be interesting as it would save me daisy chaining mixers and
loosing an i/p
 
david
 
David Salter
Senior Consultant
PSG 

Reuters Messaging: david.salter.reuters.com@reuters.net
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Get the latest news at Reuters.com <http://www.reuters.com/> 

 

________________________________

From: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
On Behalf Of hardware@doepfer.de
Sent: 13 November 2006 10:51
To: Doepfer_a100@yahoogroups.com
Subject: AW: [Doepfer_a100] Re: 8 channel cv mixer



> Hello
>
> I use two 4 channels mixers... A138a and A138c... it somehow
> makes like a cheap 8 steps
> sequencer... but it works... if you use the resets function from
> the A160 and A147 (as a
> clock).. you can have quite some good fun... using the outputs
> from A149-2 to reset
> also...
>
> but I also sometimes thought about an 8 channels mixer... but
> then you have A155 sequencer already...

All mixers A-138a/b/c can be expanded to 8/12/16... channel mixers very
easily. I could add a corrensponding remark to the DIY page if somebody
is
interested (but most details are already available on the DIY page -
exept
the corresponing solder points on the boards of A-138a/b/c).

Best wishes
Dieter Doepfer



 


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[Non-text portions of this message have been removed]

I still think an 8 input mixer without pots could be a plan - just one pot for the output - it could be pretty inexpensive module, and a space saver too? Would anyone else be interested in such a thing?

richard

  ----- Original Message ----- 
  From: David Salter 
  To: Doepfer_a100@yahoogroups.com 
  Sent: Monday, November 13, 2006 1:33 PM
  Subject: RE: [Doepfer_a100] Re: 8 channel cv mixer


  Dieter,

  that would be interesting as it would save me daisy chaining mixers and
  loosing an i/p

  david

  David Salter
  Senior Consultant
  PSG 

  Reuters Messaging: david.salter.reuters.com@reuters.net
  (t) +44 (0)20 7542 2402 | (m) 07990562402 | (f) 52699 

  Get the latest news at Reuters.com <http://www.reuters.com/> 

  ________________________________

  From: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com]
  On Behalf Of hardware@doepfer.de
  Sent: 13 November 2006 10:51
  To: Doepfer_a100@yahoogroups.com
  Subject: AW: [Doepfer_a100] Re: 8 channel cv mixer

  > Hello
  >
  > I use two 4 channels mixers... A138a and A138c... it somehow
  > makes like a cheap 8 steps
  > sequencer... but it works... if you use the resets function from
  > the A160 and A147 (as a
  > clock).. you can have quite some good fun... using the outputs
  > from A149-2 to reset
  > also...
  >
  > but I also sometimes thought about an 8 channels mixer... but
  > then you have A155 sequencer already...

  All mixers A-138a/b/c can be expanded to 8/12/16... channel mixers very
  easily. I could add a corrensponding remark to the DIY page if somebody
  is
  interested (but most details are already available on the DIY page -
  exept
  the corresponing solder points on the boards of A-138a/b/c).

  Best wishes
  Dieter Doepfer

  This email was sent to you by Reuters, the global news and information company. 
  To find out more about Reuters visit www.about.reuters.com

  Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Reuters Ltd.

  [Non-text portions of this message have been removed]



   

[Non-text portions of this message have been removed]

> Dieter,
>
> that would be interesting as it would save me daisy chaining mixers and
> loosing an i/p
>
> david
>
> David Salter
> Senior Consultant
> PSG

David,

the mod is simple:

For the old version of A-138a/b remove the dual opamp IC1 (TL062) of one of
the two modules and connect pin #2 of IC1 (i.e. the inverting input pin of
the first opamp) of both modules. The module with the missing IC1 has no
longer a output signal available. If you want to have a output of this
module connect pin #7 of IC1 (i.e. output of the second opamp) of both
modules. Now you have two outputs with adjustable levels available.

For the new version of A-138a/b its similar but here a quad opamp (TL064) is
used. Remove the quad opamp IC1 (TL064) of one of the two modules and
connect pin #9 of IC1 (i.e. the inverting input pin of the first opamp) of
both modules. The module with the missing IC1 has no longer a output signal
available. If you want to have a output connect the output sockets of both
modules. In this case the output of the second module cannot be adjusted
(different circuit compared to the old version). But you may connect the pin
header JP2 of the first module to the output of the second module. Then you
have the inverted output available.

For the polarizing mixer A-138c remove IC3 (TL062) of one of the two modules
and connect pin #6 of IC3 (i.e. the inverting input pin of the mixing opamp)
of both modules. The module with the missing IC3 has no longer a output
signal available. If you want to have a output of this module connect pin #1
of IC3 (i.e. output of the final opamp) of both modules. In this case the
level is the same for both outputs. The master control of the second module
has no function.

We already discussed a simple "mixing expander" module that could be used to
add 5 more inputs to A-138a/b. It will be about 20-30% cheaper than an
A-138a/b as no integrated circuits and no power supply are necessary for
such a simple module (only a front panel with five sockets, five
potentiometers+knobs and five resistors). How about a poll ?

Good luck,
Dieter Doepfer

hello dieter,
ok, poll coming very soon!
but, how will this passive mixer be connected to the
a138a/b? will it need soldering to the a138a/b's pcb?
or, externaly with a patchcable to one of the a138a/b
inputs?
best regards,
Bakis.



--- hardware@doepfer.de wrote:

> > Dieter,
> >
> > that would be interesting as it would save me
> daisy chaining mixers and
> > loosing an i/p
> >
> > david
> >
> > David Salter
> > Senior Consultant
> > PSG
> 
> David,
> 
> the mod is simple:
> 
> For the old version of A-138a/b remove the dual
> opamp IC1 (TL062) of one of
> the two modules and connect pin #2 of IC1 (i.e. the
> inverting input pin of
> the first opamp) of both modules. The module with
> the missing IC1 has no
> longer a output signal available. If you want to
> have a output of this
> module connect pin #7 of IC1 (i.e. output of the
> second opamp) of both
> modules. Now you have two outputs with adjustable
> levels available.
> 
> For the new version of A-138a/b its similar but here
> a quad opamp (TL064) is
> used. Remove the quad opamp IC1 (TL064) of one of
> the two modules and
> connect pin #9 of IC1 (i.e. the inverting input pin
> of the first opamp) of
> both modules. The module with the missing IC1 has no
> longer a output signal
> available. If you want to have a output connect the
> output sockets of both
> modules. In this case the output of the second
> module cannot be adjusted
> (different circuit compared to the old version). But
> you may connect the pin
> header JP2 of the first module to the output of the
> second module. Then you
> have the inverted output available.
> 
> For the polarizing mixer A-138c remove IC3 (TL062)
> of one of the two modules
> and connect pin #6 of IC3 (i.e. the inverting input
> pin of the mixing opamp)
> of both modules. The module with the missing IC3 has
> no longer a output
> signal available. If you want to have a output of
> this module connect pin #1
> of IC3 (i.e. output of the final opamp) of both
> modules. In this case the
> level is the same for both outputs. The master
> control of the second module
> has no function.
> 
> We already discussed a simple "mixing expander"
> module that could be used to
> add 5 more inputs to A-138a/b. It will be about
> 20-30% cheaper than an
> A-138a/b as no integrated circuits and no power
> supply are necessary for
> such a simple module (only a front panel with five
> sockets, five
> potentiometers+knobs and five resistors). How about
> a poll ?
> 
> Good luck,
> Dieter Doepfer
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 


Bakis Sirros - Parallel Worlds
[Doepfer_a100] group owner
http://www.parallel-worlds-music.com
http://www.myspace.com/parallelworldsmusic
http://www.shimarecords.co.uk
http://www.rubber.gr
Athens-Greece


 
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> hello dieter,
> ok, poll coming very soon!
> but, how will this passive mixer be connected to the
> a138a/b? will it need soldering to the a138a/b's pcb?
> or, externaly with a patchcable to one of the a138a/b
> inputs?
> best regards,
> Bakis.

It will be necessary to solder 2 wires to the existing A-138a/b.

I also think about to pick up Florians idea concerning a crossfade mixer.
I'm not yet sure if it will be realized as a expansion module for an
existing mixer A-138a/b or as a new module (A-138d ?). And we have to try
different circuits to find out the control behaviour (i.e. the crossfade
characteristics/response).

Thank you
Dieter Doepfer

ok, thanks for the info Dieter.
regarding florian's suggestion: yes it is a great idea
and it would be better to be realized as a separate
module(a138d) in my opinion as i am not too keen on 
soldering...
best regards,
bakis.




--- hardware@doepfer.de wrote:

> > hello dieter,
> > ok, poll coming very soon!
> > but, how will this passive mixer be connected to
> the
> > a138a/b? will it need soldering to the a138a/b's
> pcb?
> > or, externaly with a patchcable to one of the
> a138a/b
> > inputs?
> > best regards,
> > Bakis.
> 
> It will be necessary to solder 2 wires to the
> existing A-138a/b.
> 
> I also think about to pick up Florians idea
> concerning a crossfade mixer.
> I'm not yet sure if it will be realized as a
> expansion module for an
> existing mixer A-138a/b or as a new module (A-138d
> ?). And we have to try
> different circuits to find out the control behaviour
> (i.e. the crossfade
> characteristics/response).
> 
> Thank you
> Dieter Doepfer
> 
> 
> 
> 
> 
> 


Bakis Sirros - Parallel Worlds
[Doepfer_a100] group owner
http://www.parallel-worlds-music.com
http://www.myspace.com/parallelworldsmusic
http://www.shimarecords.co.uk
http://www.rubber.gr
Athens-Greece


 
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