Wiardgroup

All transpositions should be possible at the controller. But to 
save money, digital systems have no negative supply and cannot 
add the correct negative offset to satisfy the mathematics.

The normal 10 octave control range of the coarse tuning knobs 
covers the audible 20 Hz to 20,000 Hz range. The expaned range 
is only required to compensate for cost reduced digital 
controllers.

> The VCA mod is simply that Grant has found that by moving 
some of the
>  signals around,  crosstalk from the VCO is greatly reduced.  
When
> using an unmodified VCA to gate a Sine Wave for FM, the pulse 
wave is
> faintly present. even when fully closed.  This mod greatly 
reduces
> this crosstalk, making them much more useful as an 
independent
> circuit, without the trace presence of the pulsewave signal of 
the
> mother VCO.

I have to admit, this one got by me. A typical engineering problem 
of concentrating on making a connection, but not testing the 
disconnect state.

There is a ground loop on the PC board which causes bleedthru. 
Moving one resistor fixes this.

Remove board screws from the board side only.

The resistor is the 220 ohm 1/4 watt next to two 100Ks by the 
CA3080 next to the bottom ribbon cable. Remove the CA3080 
from its socket. Clip out the existing 220 ohm resistor and solder 
a new 220 ohm resistor across pins 2 and 3 of the CA3080 
socket. Reinstall the CA3080.

> I just received another Borg, and it does not have this mod.  It 
goes
> off to Wisconsin tomorrow...

The new mode was custom engineered for Gary.

> > Omni Filter gain mod
> 
> The OmniFilter gain mod was a way of compensating for the 
lower output
> of the Omni in Bandpass mode.  It simply gives gain to the 
inputs when
> they are turned all the way up.  It allows one to overdrive the 
Filter
> even when you are using a single source.

Also custom engineered for Gary.
> 
> >  
> > Noise Ring Sync
> 
> This allows for the syncronization of the Clock circuit of the 
Noise
> Ring with an external signal.  I thought that, in lieu of having an
> external clock input, being able to sync the internal osc 
provides
> some sort of way to set the relationship of the Noise ring to 
other
> time based modules in a patch.
> 

The new Noise Ring faceplates in Black or Blue add this feature.

With the exception of the VCA bleedthru, all the mentioned mods 
are exhancements to already exceptional performance.