nel cooling fins. Temperature sensors, attached to the inte- rior of the tunnel, control the cooling fans. The fans are normally off; if the program material contains sustained loud passages demanding high power, the fans will turn on to increase cooling.
Autoformers
All solid state power amplifier output circuits work best into what is called an optimum load. This optimum load may vary considerably from what a loudspeaker requires. In the case of more than one
loudspeaker connected in parallel, the load to the power amplifier may drop to two ohms or even less. A power amplifier connected to a load that is lower than opti- mum, causes more output current to flow, which results in extra heat being generated in the power output stage. This increase in temperature will result in a reduced life
expectancy for the amplifier.
The Autoformer creates an ideal match between the power amplifier output stage and the loudspeaker. Refer to figure 10. A McIntosh amplifier with an Autoformer can be used to safely drive multiple speakers without reducing the life expectancy of the power amplifier.
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 de- sign and manufacturing of Autoformers is leg- endary in the high fidel- ity industry. McIntosh
Block Diagram |
of both |
Amplifier Channels |
Figure 11
16
