The special Balanced Dual Core Autoformer creates an ideal match between the power amplifier output stage and the loudspeaker. A McIntosh amplifier with an Autoformer can be used to safely drive multiple speakers without re- ducing the life expectancy of the power amplifier. Refer to figure 13.
Figure 13
There is absolutely no performance limitation with an Autoformer. Its frequency response exceeds that of the out- put circuit itself, and extends well beyond the audible range. Its distortion level is so low it is virtually impossible to measure.
In the rare event of a power amplifier output circuit fail- ure, the McIntosh Autoformer provides absolute protection from possible damage to your valuable loudspeakers. The unequaled expertise of McIntosh in the design and manu- facturing of Autoformers is legendary in the high fidelity industry. McIntosh engineers know how to do it right.
Figure 14
Power Output Meter
The McIntosh MC1201 has a huge hand built Output Watt Meter that responds 95% full scale to a single cycle tone burst at 2kHz. Refer to figure 14. Voltage and current out- put are electronically measured, multiplied and fed to a special circuit that accelerates the pointer movement in the upward direction. When the pointer reaches its peak it pauses only long enough for the human eye to perceive its position, then drops. It is almost 10 times faster than a pro- fessional VU meter.
A front panel switch is provided to change the meter to the Watts Hold Mode of operation. This allows fast upward movement of the pointer but greatly increases Hold Time at the peak of its travel. The highest power output of the source material is thus recorded.
Protection Circuits
The MC1201 incorporates a version of the McIntosh Sen- try Monitor Output Transistor Protection Circuit. Refer to Figure 15. There is absolutely no compromise in sonic per- formance with this
circuit, and it en- sures safe opera- tion of the ampli- fier under even the most extreme oper-
ating conditions. The different types
of protection cir- cuits incorporated
in the MC1201 in- sure a long and safe operating life.
This is just one of
the many characteristics of McIntosh Power Amplifiers that make them world famous.
The MC1201 also includes the unique patented McIn- tosh Power Guard circuit.
Power Guard eliminates the possibility of ever overdriving the amplifier into clipping. Refer to figures 16, 17 and 18. An overdriven amplifier can produce both audible and inaudible distortion levels exceeding 40%. The au- dible distortion is un- pleasant to hear, but the inaudible ultrasonic dis- tortion is also undesir-
14
