I wanna advice how to make the proper way to do a balance potentiometer for audio.
I'm using 100K ladder resistor as volume control but also I use AVC.
TIA
Felipe
I'm using 100K ladder resistor as volume control but also I use AVC.
TIA
Felipe
The ideal way? Buffer the volume control signal and use a dedicated half-and-half balance control, or make your own by using half the steps of a ladder attenuator.
Otherwise the hacked single pot with two series resistors works well enough for 99% of users. Buffering is critical for good response of passive attenuators.
Otherwise the hacked single pot with two series resistors works well enough for 99% of users. Buffering is critical for good response of passive attenuators.
Thanks Rayma how do you calculate the 30K resistors? The 100K pot is lin or log? It's OK always 100K pot or depends the value of volume pot? Where to install: I guess before the volume pot right?
Just before the volume control. This circuit is for a linear balance pot.
Post your schematic and this will be easier, since the values depend on your circuit.
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That's I want to know: how to calculate depend the circuit?
My case I have only two options: 100K ladder resistor attenuator & AVC (autoformer volume control)
Input always low impedance.
Your schematic seem always have attenuation the 30K resistors in series?
My case I have only two options: 100K ladder resistor attenuator & AVC (autoformer volume control)
Input always low impedance.
Your schematic seem always have attenuation the 30K resistors in series?
Put a differential receiver in the front, pick unbalanced signal from it and regulate it under unbalanced manner as you wish, put a fully-differential amplifier as the last unbal->bal stage.
With two independent "channel balance" pots you have independent knobs and independent shafts. If you want, you can set the left one to 30% rotation and the right one to 55% rotation. You can't do that with a dual gang pot having a single knob and a single shaft.
Ah, now I understand but I can't see the advantatge. Can be more simple two mono volume pots.
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You'll never manage exact match unless it's two stepped attenuators.
There are preamps like that, FWIW.
The First Watt B1 with Korg Triode includes two separate, single-gang potentiometers for gain adjustment. One pot for the Left channel and another pot for the Right. Link to review including photos.
A diyaudio member inquired, "When you have dual mono pots without any clicks to ensure same setting of both pots, then you have to do the "tracking" by "eye and/or ear"?"
And Nelson Pass answered, "I would have thought, but I find that separately dialing them up makes you more aware of the balance. It doesn't bother me at all. Perhaps Mark Levinson's preamp had something....."
(Here is a link to his post.)
I've attached an image of the Mark Levinson preamp which I (MJ) think Nelson Pass is talking about. It has two balance pots and a volume pot.
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A diyaudio member inquired, "When you have dual mono pots without any clicks to ensure same setting of both pots, then you have to do the "tracking" by "eye and/or ear"?"
And Nelson Pass answered, "I would have thought, but I find that separately dialing them up makes you more aware of the balance. It doesn't bother me at all. Perhaps Mark Levinson's preamp had something....."
(Here is a link to his post.)
I've attached an image of the Mark Levinson preamp which I (MJ) think Nelson Pass is talking about. It has two balance pots and a volume pot.
_
Attachments
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Some schematics & formulae to get the appropiate values for pots & values of resistor if needed.
Have a look at Douglas Self's book "Small Signal Audio Design". The 2nd edition has two full chapters about this (ch. 13 & 14), with large numbers of tables, graphs, formulae, and discussion. The publisher's website (Focal Press) has the book's Table Of Contents online and viewable; I took a screen capture image of one page, attached below.
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+1 While not exhaustive, or "trendy", Self's SSAD is for-sure your First Stop for volume/balance networks.