What is the Input Impedance of the ISA 828?

Pressing the Z In switch steps through each of the four transformer pre-amp input impedance values, as indicated
by the corresponding LEDs. By selecting different values for the impedance of the ISA 828 transformer input, the
performance of both the ISA 828 pre-amp and the microphone connected can be tailored to set the desired level and
frequency response. The impedance values are as follows:

Low – 600 Ω

ISA 110 – 1k4 Ω

Med – 2k4 Ω

High – 6k8 Ω

A guide to setting input impedance is available in the Applications section of the ISA 828 Manual.