The article refers to the CM4-750, CM3-750, and CM2-750 70 volt amplifiers with Dual Mode Amplification.
Dual Mode Amplification – The unique CM series amplifiers are designed to play into either high impedance 70 volt loads (Hi Z) or into traditional 4 or 8 ohm loads (Lo Z). The CM amplifiers are stable to 2 ohms.
Power Output (70 V / 100 V): 750W per channel
Power Output (8Ω / 4Ω): 625W per channel
Simple Mode A/B dip switches allow the user to change the channel output independently depending on the speaker types in use. The CM amplifiers can run a 70V line in Mode A or low impedance in Mode B, either in stereo or mono operation. The CM2-750 has 2 switches, the CM3-750 has 3 switches, and the CM4-750 has 4 switches. Switches UP for Mode A = 70V, switches DOWN for Mode B = Low Impedance.
Common use applications:
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