It's not an impedance issue. That kind of problem is more typically a gain mismatch issue. However, the gain and sensitivity specs on all of your equipment look pretty conventional and compatible. I'd suspect that either you have a bad connection or cable somewhere (although that would seem not to explain why both channels have the problem), or something isn't working properly.
I'm assuming that you have the gain selector switch on the rear of the GCPH set to its maximum position. If not, that could certainly account for the problem.
The only impedance spec that looks a bit atypical is the Blueberry's output impedance of 3.5K, which is higher than usual. That will not affect volume significantly, because it is still very small in relation to the amp's 100K input impedance, but it might result in some upper treble rolloff if the interconnect cable is long and/or high capacitance.
Regards,
-- Al
I'm assuming that you have the gain selector switch on the rear of the GCPH set to its maximum position. If not, that could certainly account for the problem.
The only impedance spec that looks a bit atypical is the Blueberry's output impedance of 3.5K, which is higher than usual. That will not affect volume significantly, because it is still very small in relation to the amp's 100K input impedance, but it might result in some upper treble rolloff if the interconnect cable is long and/or high capacitance.
Regards,
-- Al