It is often necessary to patch a CV output to multiple modules. When this is being done with a 'crucial control voltage' such as 'pitch' e.g. using a CV to tune 2 or more VCOs, it is important that each 'INPUT' gets exactly the same voltage. To prevent potential voltage differences due to variations in impedance of patch leads and patch points, it is preferable to use a buffered output that positively drives each input independently.

The ED129 has two sets of buffered outputs configured to nominally provide a 1-in/2-out buffered expander and a 1-in/3-out buffered expander. If the 2nd, lower, [IN] jack is not used then the first section becomes a 1-in/5-out buffered expander.

The ED129 is specifically designed for CV expansion but will work equally well with audio signals.

Although normally supplied with either 3.5mm or 4mm jacks, the ED129 can also be supplied with a mix i.e. [IN] jacks in one format, [OUT] jacks in the other to allow mixed format systems to be easily patched.

The ED129 uses 0.1% matched resistors to achieve a close tracking (typically +/-0.2%) when driving multiple VCO's and should be better than 6 cents over a 5 octave range.

Build Guide