Doepfer

Hi, I'm a newbie to the group and to doepfer products but I thought I'd have a little go building a theremin/synth hybrid machine from (mostly) doepfer parts. I've got the thing more or less put together:

(2 a-178 theremin modules, a a-114 ring modulator, a a190-2 midi unit and doing most of the work the a-111-5 mini synth voice, the panel version of the Dark Energy)

There's also a space for a bucket bridge analogue delay but I'm still saving my pennies for one of them.

I was originally going to build the thing around the Dark energy.

Anyway.. It's working quite nicely but does anyone know a nice clean way of inverting the CV from one of the theremins so it will perform like a classic theremin and kill the sound when your hand approaches the volume antenna as opposed to making the sound louder?

http://i652.photobucket.com/albums/uu243/MarbleMad/therasynth.jpg

Are there any additional mods to the theremin modules? I know they have a bit of a rep for not being very linear. One of my modules was second hand and has some kind of mod involving the antenna but I can't figure out what it's all about and as far as i can tell it performs just like the new one.
I've already replaced the horrible transistor radio aerials with some nice antenna made from gas pipe and they work very nicely but I would like to get the volume behaviour right.

Use a voltage inverter, like the A175.

-Monroe

On Wed, Oct 27, 2010 at 2:02 PM, mr_marble_madness <
kinetic-arts@ntlworld.com> wrote:

>
>
> Hi, I'm a newbie to the group and to doepfer products but I thought I'd
> have a little go building a theremin/synth hybrid machine from (mostly)
> doepfer parts. I've got the thing more or less put together:
>
> (2 a-178 theremin modules, a a-114 ring modulator, a a190-2 midi unit and
> doing most of the work the a-111-5 mini synth voice, the panel version of
> the Dark Energy)
>
> There's also a space for a bucket bridge analogue delay but I'm still
> saving my pennies for one of them.
>
> I was originally going to build the thing around the Dark energy.
>
> Anyway.. It's working quite nicely but does anyone know a nice clean way of
> inverting the CV from one of the theremins so it will perform like a classic
> theremin and kill the sound when your hand approaches the volume antenna as
> opposed to making the sound louder?
>
> http://i652.photobucket.com/albums/uu243/MarbleMad/therasynth.jpg
>
> Are there any additional mods to the theremin modules? I know they have a
> bit of a rep for not being very linear. One of my modules was second hand
> and has some kind of mod involving the antenna but I can't figure out what
> it's all about and as far as i can tell it performs just like the new one.
> I've already replaced the horrible transistor radio aerials with some nice
> antenna made from gas pipe and they work very nicely but I would like to get
> the volume behaviour right.
>
>  
>


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

On 28/10/2010 01:34, Monroe Eskew wrote:
> Use a voltage inverter, like the A175.
>
> -Monroe
>
Thanks.
I guess this is 2 of these:
http://www.doepfer.de/DIY/a100_diy.htm
*Inverting amplifier.*



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

Hi,

> I guess this is 2 of these:
> http://www.doepfer.de/DIY/a100_diy.htm
> *Inverting amplifier.*
Yes -> http://www.doepfer.de/DIY/amp_inv.gif

Florian

mr_marble_madness wrote:

> I was originally going to build the thing around the Dark energy.
> 
> Anyway.. It's working quite nicely but does anyone know a nice clean way 
> of inverting the CV from one of the theremins so it will perform like a 
> classic theremin and kill the sound when your hand approaches the volume 
> antenna as opposed to making the sound louder?
> 

the Dark Energy (and presumably the modular version)
has an inverter.

www.doepfer.com > PRODUCTS > DARK ENERGY >
Dark_Energy_technical_information.pdf

It's accessed by  internal jumper pins.

andy butler

> 
> the Dark Energy (and presumably the modular version)
> has an inverter.

For the LFO outputs not usable on VCA input as far as i can tell.

mr_marble_madness wrote:
>  
> 
> 
>  >
>  > the Dark Energy (and presumably the modular version)
>  > has an inverter.
> 
> For the LFO outputs not usable on VCA input as far as i can tell.
> 

Why would I take time to advise you with nonsense? ;-)

The input of the inverter is available internally.
When the DE comes from the factory there's a jumper connecting it
to the Output of LFO1.
...and of course, the output of the inverter is the socket marked
/LFO1

So, it's rather trivial to patch the output of the inverter
to the VCA input.
Somewhat more taxing to remove jumper JP7 from the board and connect
your volume control to the lower or the two pins, which is
the input to the inverter.



happy handwaving

andy

> Why would I take time to advise you with nonsense? ;-)
I don't know.. I often dispense nonsensical advice.
> Somewhat more taxing to remove jumper JP7 from the board and connect
> your volume control to the lower or the two pins, which is
> the input to the inverter.
>
Ah <sound of the penny finally dropping>
I get it. That's perfect Thanks.