Bob101
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- Apr 12, 2021
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On all A-Sxxxx (from 1100 and up, not sure about the 1000) the tone control circuit has an automatic bypass mode via a relay. There is no 'input direct' or 'tone defeat' push switch. The bypass is activated automatically and only when both the Treble and Bass knobs are in the middle position (straight up, there is little notch-feel).
The tiniest of amount you move one knob in any direction out of that notch, you will hear a little mechanical 'click' in the amp. That's the relay that switches the tone-board into or out of the signal path. There is a momentary, harmless, muting of the output: the time it takes the relay to physically switch (a mere fraction of a second, but audible). Only when you put both tone control knobs back in 'neutral' the tone control circuit gets bypassed again via the same relay, so same little click, same momentary muting. No other movement should interrupt output. There is a sort sort of exception. Example: say, you keep the Bass in neutral, and turn the treble from left to right, or vice-versa, crossing the middle position, the tone circuit will, for the brief period both knobs were in the upright position, switch the relay...
The tiniest of amount you move one knob in any direction out of that notch, you will hear a little mechanical 'click' in the amp. That's the relay that switches the tone-board into or out of the signal path. There is a momentary, harmless, muting of the output: the time it takes the relay to physically switch (a mere fraction of a second, but audible). Only when you put both tone control knobs back in 'neutral' the tone control circuit gets bypassed again via the same relay, so same little click, same momentary muting. No other movement should interrupt output. There is a sort sort of exception. Example: say, you keep the Bass in neutral, and turn the treble from left to right, or vice-versa, crossing the middle position, the tone circuit will, for the brief period both knobs were in the upright position, switch the relay...
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