5-2: Amplifier Module; Specifications; Power Supply Circuit - Eiki ESL SERIES Service Manual

AMPLIFIER MODULE
Refer to Amplifier Circuit Diagrams for the following:
A. Specifications
1. Solid State, "2" IC and "8" transistors
2. Output Power: 25 watts RMS 8 ohm load
15 watts RMS for Models SSL-OL & SSL-1 L
3. Distortion: Less than 5% at 400Hz
Less than 3% at 1 KHz
4. Wow & Flutter: Less than 0.2% WRMS.
5. Frequency Response: Optical 50Hz - 7000Hz ±4db
Magnetic 50Hz - l 2000Hz ±4db
6. S/N ratio of the amp: 60db
7. MIC input impedance: 600 ohm and up (Hi Z)
8. MIC input level: lOmv max.
9. Speaker Jacks: 8 ohms
10. Aux output: 600 ohm un-balanced -20db to Odb (1 .4V)
1 OK ohm+ l 9db (7 .OV)
B. Amplifier Power Supply Circuit
AC power to the amplifier is supplied from the 46V AC secondary windings of the trans-
former through pins #1 & #2 of the 9 pin socket (MT-9P), dual diodes D-4 & 5 bridge
rectifier, filtered by capacitor C-35 providing the amplifier voltage of approximately 62V DC.
The 8V AC transformer secondary winding supplies AC exciter lamp voltage through pins #4
&
#5 of the 9 pin socket. Dual diodes D-6
&
7 form a bridge rectifier which is filtered by
capacitor C-36, C-37, and C-38. Zener D-3 provide a base reference to TR-7. R-42 is a current
sense resistor serving as feedback to TR-8's base. TR-7 acts as a series regulator with a voltage
sense from TR-8 to maintain the 3.5 volt to 4 volts. DC Exciter Lamp voltage is routed
through pins #8-9 of 9 pin socket to the exciter lamp.
In magnetic playback the base input voltage to TR-7 is held at OV, turning TR-7 "OFF".
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