Red LLama, Stupidly Wonderful Tone Control problem

[reddesert]

@reddesert:

I think I was expressing that it sounds like the filter is always on (i.e. the treble is clearly rolled off JUST AS IF the had maxed out the treble roll off on the tone control).  So effectively, it IS always fully on, the question on the table is why?

I fully understand the calculations involved, and in fact if you look at Mark Hammers original posting on this control, as I did to get the idea in the first place, he is somewhat agnostic about the "correct" values to use, simply stating that ratio is important to control gain loss (and of course the cap value must be chosen appropriately.

I think you are likely correct in your second paragraph and that the values in use in MY pedal are not capable of working correctly.  Either because they are objectively (not relatively) low, or because of some interaction with the 4049 chip, or some combination of the two factors.

IMO, it appeared that the tone control was fully on because you had "tone suck." That phrase has become overused, but originally it seems to have meant treble loss due to loading a high impedance output by a low impedance circuit.  Such as a guitar pickup that gets loaded by a low impedance input, or the capacitance of a lot of unbuffered cable.  Or in this case the 4049's output being loaded by the low impedance tone control.

My point about the voltage dividers was that the volume pot came after the voltage division of the tone control  - the volume pot, being a higher value, wasn't loading the tone control.

[Andrekp]

@reddesert:

I think I was expressing that it sounds like the filter is always on (i.e. the treble is clearly rolled off JUST AS IF the had maxed out the treble roll off on the tone control).  So effectively, it IS always fully on, the question on the table is why?

I fully understand the calculations involved, and in fact if you look at Mark Hammers original posting on this control, as I did to get the idea in the first place, he is somewhat agnostic about the "correct" values to use, simply stating that ratio is important to control gain loss (and of course the cap value must be chosen appropriately.

I think you are likely correct in your second paragraph and that the values in use in MY pedal are not capable of working correctly.  Either because they are objectively (not relatively) low, or because of some interaction with the 4049 chip, or some combination of the two factors.

IMO, it appeared that the tone control was fully on because you had "tone suck." That phrase has become overused, but originally it seems to have meant treble loss due to loading a high impedance output by a low impedance circuit.  Such as a guitar pickup that gets loaded by a low impedance input, or the capacitance of a lot of unbuffered cable.  Or in this case the 4049's output being loaded by the low impedance tone control.

My point about the voltage dividers was that the volume pot came after the voltage division of the tone control  - the volume pot, being a higher value, wasn't loading the tone control.

Fair enough. You may well be correct about the exact "why," but at this point, it is academic. The assumption always was that barring a problem with my layout, that it was due to the values of the pots. Changing that, as expected, rectified the problem. If a definitive answer can be found and explained electronically, then great, but at this point the immediate problem is simply solved by higher value pots. No offense, as you are probably correct. 


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