FYI:
The prevailing rule of thumb is that the input impedance of amplifiers should be 10 X greater than the output impedance of preamplifiers.
The Pass XA30.5 input impedance is spec'd at single ended: 15K Ohms and at balanced: 30K Ohms.
c-j recommends an amplifier input impedance of 20K Ohms for all of the above mentioned c-j preamps. All c-j's are single ended only.
The Aesthetix Calypso suggests recommended amplifier loads of single ended: 10K Ohms or greater and balanced: 20K Ohms or greater.
Couldn't find anything specifically re: the EAR 868, but Ear does suggest looking at the EAR 912 as this what the 868 what based upon. The EAR 912 output impedance is spec'd at: 600 Ohms.
The Zesto Leto output impedance is spec'd at: 150 Ohms both single ended and balanced.
The prevailing rule of thumb is that the input impedance of amplifiers should be 10 X greater than the output impedance of preamplifiers.
The Pass XA30.5 input impedance is spec'd at single ended: 15K Ohms and at balanced: 30K Ohms.
c-j recommends an amplifier input impedance of 20K Ohms for all of the above mentioned c-j preamps. All c-j's are single ended only.
The Aesthetix Calypso suggests recommended amplifier loads of single ended: 10K Ohms or greater and balanced: 20K Ohms or greater.
Couldn't find anything specifically re: the EAR 868, but Ear does suggest looking at the EAR 912 as this what the 868 what based upon. The EAR 912 output impedance is spec'd at: 600 Ohms.
The Zesto Leto output impedance is spec'd at: 150 Ohms both single ended and balanced.