The outputs of the Allnic L-1500 are transformer coupled, and are described in its manual as having an output impedance that remains essentially constant (at 150 ohms) across the entire audible frequency range. So it should be fine driving 10K.
It would be a different story in the case of the some tube-based preamps which have capacitively coupled outputs. In those cases the output impedance might rise to much higher values in the deep bass region than the specified output impedance, which is usually based on a mid-range frequency such as 1 kHz. But that is not the case here.
Regards,
-- Al
It would be a different story in the case of the some tube-based preamps which have capacitively coupled outputs. In those cases the output impedance might rise to much higher values in the deep bass region than the specified output impedance, which is usually based on a mid-range frequency such as 1 kHz. But that is not the case here.
Regards,
-- Al