California Audio Labs CL-2500 SSP Repairs... Schematics?

I have two CAL SSP units with what seem to be identical volume control issues.  I am trying to find out if anyone has the schematics so I can troubleshoot these issues.  I am thinking this may be a common problem amongst these wonderful preamps.  I am open to any information that might be out there.  Can anyone help?

I emailed Scott Morris (one of the original CAL engineers) but have not heard back from him.

My 2500 MCA is a jewel and I don't want to give up this fine matching equipment if there is a chance to repair it...