CJ is notorious for having a lot of gain, the classic has 27db. The McCormack only needs 2.25 volts for its full 500 watt per channel output. A CD or Dac output should be 2v. So the OP should be able to get full output from a preamp that has 1db of gain.
The only two solutions here are imhififan’s suggestion for attenuators, or a different preamp with less gain.
The only two solutions here are imhififan’s suggestion for attenuators, or a different preamp with less gain.