It's not processor power/speed or system resources, it's the fact that on the Mk1 there is physically no path for the processor to sample; on the Mk2 there is a sample path, but the sample rate is insufficiently high to accurately resolve anything above 15kHz.
I suggested a self-sampling EQ system for the Mk2 based on it's speech mike input and the ability to sample, but above 15k it would not work. That would mean that you would only be able to do output level compensation below this level. However, it would be pretty useless for decent ripping on the AUX port.
One of the few remaining Mk1 owners...
#00015