Cooper Sound Systems CS 106 Direct Out Modification

The Cooper CS 106 mixer continues to be a workhorse of the location recording industry. At the time of its initial design, multi track field recorders were not much in use and the isotrack recording of each input was not as common as it is today. The CS 106 channel outputs, direct outputs, whether picked up at the 1/4 inch direct out jack or at the 1/4 inch insert jack were low in level, existing somewhat lower than a low line level but higher than mic level. To make isotracking more easily accomplished, we have designed a direct out modification for the CS 106 input module. The features include:
 

1. The direct out gain is increased by 10 dB. More gain (or less) may be ordered at time of installation and is easily changed at a later time. Other signal levels in the CS 106 are unaffected.
2.  The direct out is now balanced. In addition to the increased isolation to common mode interference of the direct out signal, the headroom of the direct out is increased by 6 dB.
3. The direct out is now after the equalizer section of the input module. When editors make use of the isotrack information it is relatively easy to match the gain difference of the isotrack to the mix, but matching any EQ that has been done is quite difficult and time consuming for the editor. By taking the direct out post EQ it will, of course, automatically match.
4. Our modified direct out is Pre Fader.
5. An input module containing our modification plugs into and out of the 106 chassis the same as ever. There are no wires to disconnect should you need to swap modules around in your mixer, loan an input module to a colleague, or borrow one should you need an extra input channel.
6. Our modification allows full use of all slots in the mixer. It does not tie up the extra space in the 106+1. The direct out 1/4 inch tip sleeve jack is replaced with a 1/4 inch tip ring sleeve jack and the balanced pre fader signal for each input module is available on its own 1/4 inch jack.
7. The direct out is now isolated from degrading the mix signal. Momentarily short one side or both of the direct out signal, connect it to an input having 48 Volt Phantom, our direct out doesn't care. It handles all this with ease. Yes, you read it correctly, our direct out modification is undamaged by momentary or permanent connection to an input with the 48 Volt Phantom turned on.
8. Over the years, op amps have continued to improve in signal to noise ratio and distortion characteristics. We use op amps not available at the time of the 106's design. In addition, we replace both of the op amps in the EQ section of the input module, improving the distortion and overload characteristics of the EQ section of the 106.
9. No holes are cut in the chassis of the CS 106 for this modification. Except for the label noting the modification, the CS 106 looks as it did before. It simply performs better and is more user friendly.

The cost of the direct out modification is $175.00 per input, installed, tested and warranted for one year. Often, the cables now in use for isotracking can be modified at little cost to a balanced configuration. However, if new cables are needed, a 1/4 inch tip ring sleeve plug to male XLR starts at about $25.00, each. Gold plated connectors and Canare cable, of course. Other cable configurations are available.