[Mike Rivers[_2_]]

On 6/5/2018 10:21 PM, wrote:
I guess the question to ask is, on Uncle Joe's
1970 color Philco, is the volume located in the
input stage, or the power amp side?

Same for the volume on a stereo receiver in
the home.

On a TV set, the input is an RF signal, usually a pretty weak one, so
there's no need to attenuate it. The "volume" control is in the audio
portion of the circuitry, usually a stage or two before the power
amplifier. Same with a home stereo receiver.

A microphone preamp often has an attenuator ahead of the input stage
because, given the wide range of sounds (SPL) that might be encountered
and a fairly wide range of microphone sensitivity (millivolts out for a
given SPL), the input to the gain stage needs to be attenuated so as not
to overdrive it and cause clipping (distortion).

To be picky, a volume control is a special application of an attenuator,
and "volume" usually refers to sound level rather than voltage level.


--
"Today's production equipment is IT based and cannot be operated without
a passing knowledge of computing, although it seems that it can be
operated without a passing knowledge of audio" - John Watkinson

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