This applies to the ISA 428 MkII
- Line Input: 10k Ω
- Inst Input: >1M Ω
Mic Input:
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 428 MkII transformer input, the performance of both the ISA 428 MkII pre-amp and the microphone connected can be tailored to set the desired level and frequency response. The impedance values are as follows:
- Low – 600Ω
- ISA 110 – 1k4Ω
- Med – 2k4Ω
- High – 6k8Ω