Stereo record player, line input unit

The stereo record player/ line input unit is shown in Figure 3-29. The channel numbers are CH5R. , recording
deck (TAPE), tuner (TUNER), laser record player (CD) and other stereo two-channel audio signal sources,
you can also input the volume output signal of a laser video disk player or tape recorder, but each unit can only
Select one of the
signals through switches SA501A, SA01B or crucian carp‰IA, switch ‰1B, SA6(}IC. Taking CHs as an example, when using the electromagnetic record player to input clock ‰]A and switch B to the 1st position, this The stereo phono input amplifier is composed of IC501A and IC501B, and
the RIAA equalization network is composed of ‰1, island∞, C504, R503, Ros and R509. For
the input of recording deck, tuner, ∞phono player, video recorder and VCD player The audio signal is directly sent to the amplifier Icaol (in Figure 3-31) through the conversion of ‰I.
oRPsoi is a dual synchronous input signal attenuation potentiometer, used to adjust the intensity of the input signal. R512 and
Rs24 are isolation resistors. RP50z The double potentiometer is a cross attenuator designed for continuous playback of dance music in dance halls, and is also called a hybrid
attenuator. When the potentiometer is turned, the program broadcast from one channel (such as CH5L, CH5R) can gradually and smoothly shift
to another channel. One channel (such as CIiL, C}~R> is used to broadcast.
    In Figure 3-31, the double-pole switch, Rszs, and Rs2s form a speech coverage circuit. If you need to insert speech during the program
, you can close the switch. , to reduce the volume of the program and make the speech more prominent and clear.
    The SA601 in CH6 is a triple synchronous switch, in which ‰1A and ‰1B are used to switch the audio signal source, and SA6rO,iC
is used to switch the video signal source. For example: When switching from video recording (VTR) to VCD playback, the three sets of switches of ‰1 are switched from the third gear to the fourth gear
at the same time , and the audio signals are also switched synchronously. This is a unique function of this A and Kuang mixing console. .