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Marantz 500 schematic question

T

tranguru

Active Member
Hi all,

One of my favorite parts of the service manuals for Japanese units and handbook for US units, is the circuit description.

I have question

This is from the handbook:
lnput Amplifier - The input signal level to the input amplifier is determined by the setting of the Gain control. Within the input amplifier, the signal is ac coupled to the input of an emitter follower (Q101) and a constant current source (Q102). The output of the emitter follower is a-c coupled to the inverting input of an unbalanced differential amplifier (Q103, 0122] whose gain and roll-off slopes are controlled by the feedback network from the output of the input amplifier. The other input to that differential amplifier is derived from a potentiometer which is adjusted for proper cl-c operating point.

is this correct? isn't Q101 the current source and q102 the input emitter follower?



upload_2022-4-15_14-46-44.png

thanks
robin
 
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tranguru said:
Hi all,

One of my favorite parts of the service manuals for Japanese units and handbook for US units, is the circuit description.

I have question

This is from the handbook:
lnput Amplifier - The input signal level to the input amplifier is determined by the setting of the Gain control. Within the input amplifier, the signal is ac coupled to the input of an emitter follower (Q101) and a constant current source (Q102). The output of the emitter follower is a-c coupled to the inverting input of an unbalanced differential amplifier (Q103, 0122] whose gain and roll-off slopes are controlled by the feedback network from the output of the input amplifier. The other input to that differential amplifier is derived from a potentiometer which is adjusted for proper cl-c operating point.

is this correct? isn't Q101 the current source and q102 the input emitter follower?



View attachment 2539844

thanks
robin
Click to expand...
You're correct.
FWIW there is a sticky thread at the start of this forum devoted to errors in service manuals.
Marantz Service Manual error thread | Audiokarma Home Audio Stereo Discussion Forums
 
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