Wiardgroup

Thank you all for that useful information. I believe I understand now.

Each Wiard module in the 300 and 1200 series has a 1K limiting resistor on the output of 
the op-amp or transistor Class A buffer. This limits the output current to a safe level, even 
in the even of a complete short (like when a patch cord touches a faceplate during normal 
patching). They also protect the outputs if two outputs are connected together (see 
below).

Lets do a tiny bit of math. By Ohms law, 10 volt divided by 1000 (1K) ohms equals 0.01 
amps or 10 milliamps. Power is determined by volts times amps so, 10 times 0.01 equals 
0.1 or 100 milliwatts. The output resistors are 250 millwatts to give a time 2 margin of 
safety.

The 1K output resistor does form a voltage divider with the 50K input resistance of 
module inputs. But this voltage drop is only 2%, and not audible. For precision outputs (1 
volt per octave) the 1K resistor is placed inside the op-amp feedback loop. This keeps the 
output protection, but the voltage drop is compensated for.

Since all the output are protected by 1K resistors, you can use simple multiples to mix 
module outputs together. For example, to place Borg 1 ouptus in parallel, just run the 
same signal to both inputs and connect both ouputs to the multiple at the bottom of the 
patch bay.

Since every module input and output is fault protected, this means you can connect the 
modules without fear to any other type of module. It should be impossible for the Wiard to 
do any damage to any other kind of module, and likewise the other modules can not 
damage the Wiard modules.

So, it is safe to patch the Wiard 300 or 1200 modules to modules from other 
manufacturers.

If you are sending 10 volt outputs to 5 volt inputs, you need a simple attenuator to get the 
BEHAVIOR you expect. Take the exaple of a VCA that has a gain of one (unity) at 5 volts. 
Without an attenuator, the VCA will "clip" the 10 volt envelope and spend most of it's time 
fully on.

Now that I know whats going on, it would be trivial to convert the 1209 Joystick and 1211 
JAG module to operate at 5 volts in the native mode. This only involves changing some 
resistor values.

This is not the same as changing to banana plugs, which is machanically difficult and 
would not produce a "roadworthy" module.

Sorry for any misunderstanding. I deliberately do not look at other modern manufacturers 
products so I don't get influenced by trendy ideas. It is easier to be completely original if 
you avoid the "pollution" of what is happening now, and just concentrate on sticking to 
your own internal vision. 

I think the market needs more original thinking and less repackaging of vintage designs. 
Just repackaging someone elses design is very inexpensive, because there are no research 
and development costs. This is why some people can sell their modules so cheaply, they 
have no real investment aside from a faceplate and PC board. This does nothing to 
advance the state of the art.

All of Wiard intellectual property is utterly unique, nothing is copied (except on the 
conceptual level) from any one else. The goal is to advance the state of the art in synthesis 
in general, not just in regards to modular instruments. I think this has worked great in that 
regard (although the "cloned" designs may sell more widely).

--- In wiardgroup@yahoogroups.com, "p. hendricks" <ph@...> wrote:
>
> posted on the Doepfer list Fri Jul 7, 2006:
> 
> As long as the voltages applied to any socket are within -12V...+12V we
> guarantee that nothing can be damaged within the A-100. But even voltages
> beyond these limits will not damage most of the inputs (e.g. audio inputs
> and CV inputs with attenuators). But there is one exception: inputs and
> outputs of modules that use voltage controlled switches (e.g. A-150, A-151,
> A-152, A-154, A-155, A-148), older versions of A-150 and A-151
> (max. -8V...+8V), and CV or audio inputs without attenuators. For these
> in/outputs the voltages applied should be within -12V...+12V.
> 
> Best wishes
> Dieter Doepfer
>