As J M Fahey said.
Just off the cuff, with almost same value components either side of the output, the variation in tone obtainable will be very slight apart from not being balanced. You say you have built it; how audible are the differences you get?
The more usual ratio of components on the lift and cut sides is about 10:1, then used with log taper controls to make response at various settings similar. The penalty is of course a factor 10 attenuation. If that is too much, the only hope is to use another stage and build a linear taper feedback control type, often called the Baxandall, after the first person to use it.
Just off the cuff, with almost same value components either side of the output, the variation in tone obtainable will be very slight apart from not being balanced. You say you have built it; how audible are the differences you get?
The more usual ratio of components on the lift and cut sides is about 10:1, then used with log taper controls to make response at various settings similar. The penalty is of course a factor 10 attenuation. If that is too much, the only hope is to use another stage and build a linear taper feedback control type, often called the Baxandall, after the first person to use it.
The balance is a little off more to the right speaker I read and saw the schematic on the net for the tone I to notice that equal parts on the lift / cut apart from that it sounds good, although the bass could be better but I have this amp running for jazz classical thence the 6N3C/6J8 Tubes I will be building another amp with EL34/ 6H9C and use a better design tone control. this works well for a jazz amps. I will tweak the bass side to see if I can get better?
Mdamp,
Sorry to be an old - whatever! But you could get still more predictable results.
Firstly, the feeding impedance (input) needs to be fairly low, say <15K in order for that not to add to the tone control resistance and influence operation negatively. It might mean an impractical change, but the ideal 'feed' will be a cathode follower. That will make operation independant of what the input impedance might be. A triode with some 20K cathode resistor will have an impedance of <2K (with a series capacitor of course).
It might be that whatever you are feeding into the tone control (tuner, cd player etc.) will already have a low impedance output; in that case fine then.
Then at the output of the tone 'stack' again, the impedance needs to be rather higher than the 100K pot you have at present. Since it feeds a tube the impedance there the value can be high, as much as a 1 meg. log pot. It is also not necessary to have a separate fixed resistor from the grid to ground (the 1M you have there now.)
That will give a flat frequency pass characteristic with controls in the center and a more or less equal frequency increase-decrease. (Note that log law controls are difficult to make to track as the right/left controls; cheap models can be audibly out of track so to speak. Capacitors also have a tolerance. Not to split hairs, but such may give an audible difference between left and right channels.)
With all that in mind, I wish you joy with the addition. (Sticking my neck out where it is not required, but I am not one to be dismissive of tone controls. I notice too much difference between recordings not to use mine, while the complaint about tone controls adding phase shift and what-not is a myth. With close tolerance components the 'phase shift' in the mechanical center position is nil to negligible. But that is another story.)
Sorry to be an old - whatever! But you could get still more predictable results.
Firstly, the feeding impedance (input) needs to be fairly low, say <15K in order for that not to add to the tone control resistance and influence operation negatively. It might mean an impractical change, but the ideal 'feed' will be a cathode follower. That will make operation independant of what the input impedance might be. A triode with some 20K cathode resistor will have an impedance of <2K (with a series capacitor of course).
It might be that whatever you are feeding into the tone control (tuner, cd player etc.) will already have a low impedance output; in that case fine then.
Then at the output of the tone 'stack' again, the impedance needs to be rather higher than the 100K pot you have at present. Since it feeds a tube the impedance there the value can be high, as much as a 1 meg. log pot. It is also not necessary to have a separate fixed resistor from the grid to ground (the 1M you have there now.)
That will give a flat frequency pass characteristic with controls in the center and a more or less equal frequency increase-decrease. (Note that log law controls are difficult to make to track as the right/left controls; cheap models can be audibly out of track so to speak. Capacitors also have a tolerance. Not to split hairs, but such may give an audible difference between left and right channels.)
With all that in mind, I wish you joy with the addition. (Sticking my neck out where it is not required, but I am not one to be dismissive of tone controls. I notice too much difference between recordings not to use mine, while the complaint about tone controls adding phase shift and what-not is a myth. With close tolerance components the 'phase shift' in the mechanical center position is nil to negligible. But that is another story.)
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