Sequential circuits samplers

Hello, 
    Thanks to another member I was able to install the 8 outputs, but
I seem to have an issue now.  I can hear the 8 voices, but the level
is incredibly low (like an op-amp is not working).   Here is exactly
what I did:
I lifted up pin 11 out of the CEMs and soldered the wire from the
op-amp board to their respective places.

Then I removed an op-amp, 2 resistors, and 2 capacitors to solder the
remaining 5 wires from the op-amp board to their respective places.

When I turn on the machine and try to use it (without the ribbon cable
connecting to the jack board), I can hear the output but it is very,
very low.  I am not sure if the lack of ribbon cable would cause this
or if it is something more sinister.  

I am not sure how the upgrade operates though.  Do the main jacks
still work with the upgrade?  Even though the cable isn't connected to
the jack board, I would suspect that the main outputs would still
operate as normal, but either they don't or something is wrong.

Thanks,
Chase