1. buzz is emitted by the speakers
2. both channels
3. All inputs
4. This is with all components disconnected, only a speaker is connected.
5. Yes volume and tone knobs do have effects
Ok here are my findings (Our default position is with volume at 0, balance 50/50, bass 0, treble 0, and I am testing it with only one speaker one channel at a time) :
LEFT CHANNEL: With variable/defeat switch set to variable and turnover set at 600hz max, maxing bass makes buzz significantly thicker and bassier. Any effect of max treble is negligible. With variable/defeat switch set to defeat, max bass has no effect. Switching between source functions at 0 volume have no effect, unless bass is maxed out with variable on - then you can hear fluttering when quickly changing between source functions.
Volume effects the buzz. On all sources other than phono (tape1, tape2, aux1, aux2, tuner) turning knob has no increase until a sudden and momentary bump at level 2. Here it goes from its default "err" buzz to a louder honking "ee" buzz, then immediately back to the "err" once level 2 is passed and remains here with no change in volume until level 6 where the main change in sound is the pitch gets more "needley" and is slightly louder than default. Important note is max bass with variable on exaggerates all of this -- sound is louder, fuzzier, more distorted.
PHONO however is very different. Volume increases exponentially on its way to level 2 at which time it is suddenly muffled (the reverse of other source functions), once past level 2 volume is at a deafening level and cannot be tolerated. If I turn the balance 100% away from the channel I am currently testing (which would ordinarily put the speaker at 0 volume), then Phono behaves like the other source functions when volume is increased EXCEPT when bass is maxed out with variable on -- then the protection indicator light goes from green to red at level 3 and beyond. If I switch source functions when the amp is in this state, the red light does a quick double blink, then a momentary hold when all buzzing and all volume is turned off, then quickly back to green light and accompanying buzz at the new non-phono source function.
RIGHT CHANNEL: The only differences are 1.) the default buzz is a smidge less abrasive, 2.) there is no fluttering when max bass, variable on, volume 0 while quickly changing source functions, 3.) on all non-phono function sources there is no sudden and momentary bump at level 2 when increasing volume, it remains the default buzz until it too gets needley at level 6, and 4.) increasing volume with phono selected results in same exponential volume increase as left channel except there is no momentary muffling at level 2.
