But if there's no sound how do you know what it tastes likeThat’s the recommended approach for dialing the Mark amps (from the Mesa manuals): Start with tone controls at zero, bring up the treble to taste, then midrange, then bass.
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But seriously I'm not sure you need to have zero sound with them all off for this method to work. Also, how I taste the treble will change when I bring in some mids and bass.