I wasn't really sure where to put this as it wasn't really appropriate for any of the given topics, but I suppose it will work here.
I am wanting to make a simple passive box between my dac and headphone amp where I can adjust the channel balance. I plan to do it with a single dual gang 100k pot. My idea is to run the ground on the left on the top gang, and the ground on the right on the bottom, so that when you turn it one way, one channel gets louder while the other gets quieter, and the other way, vice versa.
Obviously this will mean the volume will be cut in half right off the bat, but will that be a huge issue if I do it before the actual amp? Is there a better way to do a single knob balance without the issue of the volume being cut in half?
I am wanting to make a simple passive box between my dac and headphone amp where I can adjust the channel balance. I plan to do it with a single dual gang 100k pot. My idea is to run the ground on the left on the top gang, and the ground on the right on the bottom, so that when you turn it one way, one channel gets louder while the other gets quieter, and the other way, vice versa.
Obviously this will mean the volume will be cut in half right off the bat, but will that be a huge issue if I do it before the actual amp? Is there a better way to do a single knob balance without the issue of the volume being cut in half?
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Its best if draw what you have in mind tbh.
If you are relying on the shunting action of the pot (its decreasing resistance) being placed across a DAC output then that won't work because the output impedance of the DAC will be so low that nothing will happen until you almost short it out.
If you meant wiring a linear pot up and taking the signal from the wiper at the midpoint setting then yes that will work, however 100k is very high and could cause HF roll off issues. That's really wiring the pot so that one side works as a normal volume control and the other works in reverse.
Best to draw it
If you are relying on the shunting action of the pot (its decreasing resistance) being placed across a DAC output then that won't work because the output impedance of the DAC will be so low that nothing will happen until you almost short it out.
If you meant wiring a linear pot up and taking the signal from the wiper at the midpoint setting then yes that will work, however 100k is very high and could cause HF roll off issues. That's really wiring the pot so that one side works as a normal volume control and the other works in reverse.
Best to draw it
"That's really wiring the pot so that one side works as a normal volume control and the other works in reverse. "
That is exactly what I mean. Screenshot by Lightshot
I'll try it out and see how it works for me. If the volume becomes too low for a usable line level, I guess I will try something else. Maybe an extra resistor to each ground to limit the range and give me more headroom. I don't think I will need to to pan fully left or right anyways.
That is exactly what I mean. Screenshot by Lightshot
I'll try it out and see how it works for me. If the volume becomes too low for a usable line level, I guess I will try something else. Maybe an extra resistor to each ground to limit the range and give me more headroom. I don't think I will need to to pan fully left or right anyways.
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Thanks guys, worked great! Volume turned out to be a non-issue.
Next, for a totally different project, I am wanting to make a passive crossfeed box, where a small bit of the left channel will feed to the right channel and a small bit of right channel feeds to the left.
This is what I am planning to do, so you can understand.
Basically, when the knob is all the way left, everything is normal(with minimal crossfeed), when in the middle, the output is basically mono, and all the way to the right, the right and left channels are inverted. Will this work out? I know these three positions will be fine, but I am unsure about everything in the middle, if it will effect frequency response, and what will happen in regards to destructive interactions of the sound.
Next, for a totally different project, I am wanting to make a passive crossfeed box, where a small bit of the left channel will feed to the right channel and a small bit of right channel feeds to the left.
This is what I am planning to do, so you can understand.
Basically, when the knob is all the way left, everything is normal(with minimal crossfeed), when in the middle, the output is basically mono, and all the way to the right, the right and left channels are inverted. Will this work out? I know these three positions will be fine, but I am unsure about everything in the middle, if it will effect frequency response, and what will happen in regards to destructive interactions of the sound.
I did, and the only issue I have is, the volume decreases towards 50%, and increases towards 0% and 100%. After matching the volume, I can't hear much frequency response issues, although the signature alters slightly to the warm side. It is difficult to know if it is in my head though, since at lower volumes, the low end would be more audible anyway.
Overall, it's a success, but it would be nice if the volume discrepancy wasn't a thing, but I can't think of a way around that passively. Perhaps it would be possible with a quad gang pot, but I am not sure if it is worth it for my purpose.
I will chalk it up to resistive division limitation and leave it there. Perhaps someone who knows more than me can chirp in a simple addition that would minimize the effect I can't think of, but I am not sweating it.
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> the volume decreases towards 50%
Your sim-screen shows "10M" amp inputs. Assuming 10 Meg, that's unlikely. And pot value is not shown.
Assuming 10k pots and 20k amp input, yes volume will drop. Assuming 100k pots to 50k amp via a long cable, volume will drop appreciably and high-end response will fall below 20KHz, "warm".
There is actually a large body of writing about cross-feed. Particularly for headphones, but much of this applies to loudspeakers also. Have you harvested/plagiarized those who walked this field before you?
Your sim-screen shows "10M" amp inputs. Assuming 10 Meg, that's unlikely. And pot value is not shown.
Assuming 10k pots and 20k amp input, yes volume will drop. Assuming 100k pots to 50k amp via a long cable, volume will drop appreciably and high-end response will fall below 20KHz, "warm".
There is actually a large body of writing about cross-feed. Particularly for headphones, but much of this applies to loudspeakers also. Have you harvested/plagiarized those who walked this field before you?
me> Looks like the Panorama knob .... maybe Mac?
Darn organic memory. And I had that knob at-hand for much of a decade.
Crown IC-150. Dual linear BUT with center-tapped tracks AND some switching, probably to ensure no cross-feed at the extremes. After one try, _I_ always left it strictly Normal. But that rig's speakers were not much further apart than the IC-150 is wide.
Darn organic memory. And I had that knob at-hand for much of a decade.
Crown IC-150. Dual linear BUT with center-tapped tracks AND some switching, probably to ensure no cross-feed at the extremes. After one try, _I_ always left it strictly Normal. But that rig's speakers were not much further apart than the IC-150 is wide.
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No. Which is why I asked here. I thought something might have been going on with high frequencies, but since I never get close to the center, I haven't really looked into.
The 10M for the amp was just for simulation purposes, I know the amp doesn't actually have that high of input impedance
I'll try a lower resistance pot and see if that fixes the high end around 50%.
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