> Hello,
>
> I have a technical question about safety in doepfer use, i¹m preparing an
> electro-acoustic performance to be presented around a fountain,
> the idea is
> to use the fountain¹s water as a sort of multiple, i mean i would build a
> box to carefully sepparate the jack¹s GND and +V, then would
> connect all +V
> to the water keeping the GND in one of my hands, this way the
> water would be
> a conducteur and my body the resistor or the attenuator for the voltage, i
> would then join GND and +V and use it as a CV source...
>
> I was testing with a 9v battery in my bathtub and could have total voltage
> attenuation control - 0v to 9v
>
> Would i be in risk here, with the doepfer connected to an ac supply
> Any major not advised thing would be envolved here
>
> To make it safer could i isolate through optocouplers the water
> line and the
> doepfer line, would this resolve any problem
> Any help, ideas
>
> Thanks in advance
>
> Best regards
> andre

I'd be very cautious with water and equipment that is connected to mains
voltage. You have to make 100% sure that any contact between water and the
A-100 power supply is impossible (mains and +/-12V).

From my point of view this would be a safe solution: Use a very long patch
cable to establish the connection between your "wet installation". The minus
terminal of the external 9V battery is connected to the GND of the cable,
the tip of the cable is used for the control voltage generated by your body
and the water. The length of the cable has to make 100% that no humidity or
water could reach the A-100 frame.

Another solution would be the usage of batteries for the A-100 power supply.
Then there is no connection between the A-100 and mains (e.g. two 12V
rechargeable batteries for +12V and -12V).

In any case you have to be very careful and I'd dissuade to realize the
project if you are not sure if you can keep all safety conditions.

Best wishes
Dieter Doepfer