User manual MCINTOSH MC60

[. . . ] 5% harmonic distortion at any power output up to 60 watts and at any frequency in the audio spectrum, 20 to 20, 000 cps; less than 0. 5% intermodulation distortion f o r all power levels up to 120 instantaneous peak watts; and noise and hum level 90 db or more below the rated output level. [. . . ] In this case connect the input lead to pin #5 and the ground lead to pin #1. When using this connection the source must not have a DC output component. Output Connections The MC-60 has output impedances of 4, 8 and 16 ohms available at either the screw terminal connector or the output socket. In addition, a 600 ohm output (balanced to ground) is available at the output socket. See schematic diagram for socket connections. It is important that the loudspeaker or other load be properly matched to the amplifier if best performance is to be obtained. Because many loudspeakers do not have voice coil impedances exactly matching 4, 8 and 16 ohms, the following table lists suggested connections for the best impedance matching. 5 to 13 ohms 8 ohms 13 to 32 ohms 16 ohms WARNING: Output plugs wired for Mclntosh 20W-2 and 50W-2 amplifiers must not be used with the MC-60 without rewiring the plug. Output connections for the MC-30 are the same as those for the MC-60. Power Connections The MC-60 operates from any 110 to 130 volt 50-60 cycles power line. (When continuous use is contemplated on 120 to 130 line volts the transformer primary should bo re-connected using the 125 volt tap. ) When the MC-60 is used with Mclntosh Pre-Amplifier equipment, tuners, or other associated equipment, the MC-60 power cord may be plugged into the receptacle at the rear of these units. When thus connected the power switch of these units controls the MC-60. [. . . ] 3V ac to Pin 9 290 148 0 11 - 12BH7 9 1 2 3& 8 4& 5 6 7 9 Fil 340 0 16 Fil 340 0 Fil 0 to 70 43K* 2. 6M* 0 to 70 12K* 20 OK 1. 2K 0 to 70 12K* 200K 0 to 70 Tube 12AX7 Pin No. 1 2 3 4&5 6 7 DC Volts No Signal 435 -46 -45 Fil 435 DC Volts at 60W out 365 AC Volts at 60W out 106 148 148 - -46 -45 6. 3V ac to Pin 9 36S . 46 -45 - 106 148 148 - a -46 -45 9 KT-88/6550 (Both tube*) 1 2 3 4 5 Fil 0 Fil 435 435 -45 - 0 0 106 110 148 110 8. 9(ripple) 370 370 Resistance Unit Off 45* 1M 270K 0 to 70 45* 1M 27 OK 0 to 70 - 6. 3V. ac to Pin 7 365 365 -45 2. 5 - 0 to 70 45* 45* 270K 0 to 70 12 0* - 6 7 5U4GB (Both tubes) 8 1 2 3 4 5 Fil . 8 440 37 5 AC 380 - 370AC - - 6 7 8 37 5 AC 440 370AC 380 15 15 0* Pins not listed are either filaments, have no voltage or are not used. [. . . ]