Schematics for Thorens TTP 2000F preamp?

Hi folks,

Does anyone know where I could find schematics for TTP 2000F preamp? Emailed Thorens, their answer was that they don't have anything for that anymore.

The peculiarity with that preamp is that it's output level seems to be too high for the TMA 2000 power amps it's paired with - can't turn the volume above around 20% of travel without things getting uncomfortably loud. According to the little information I could find, the sensitivity of the power amps is 0,7 V - seems insanely sensitive to me. Is that normal, or is there anything I can do to lower the output level of the pre-amp?