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Volume Control with Loudness and no Taps

Hi! Anyone have schematic for passive volume control with loudness compensation and 250-500K potentiometer without taps? Tapped pots are very problematic to obtain today unless ordered in quantity 100+ directly from factory.

I found schematic on Steve Bench web site (attached to this post), but I have no idea of its origin. In the books I have there are schematics, but ALL use tapped potentiometers.

Thanks in advance for any suggestion(s).
 

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I have this one, slightly simpler - I also cannot tell you its origin: (when I saw the useful circuit I just saved it with no record of where it came from)

It should be easy enough - using simulation software - to plot the frequency response curves of both circuits and see which you prefer.

The tapped pot circuits are merely a cheap approximation anyway, so no reason they are inherently better than an arrangement using a standard pot, other than they may give a lower insertion loss.

There are also circuits that use double-gang pots, so for stereo you'd need a four-gang, or two gear-coupled twin-gangs.
 

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You can place a parallel RC in series with the cold end of the pot to ground, place a switch across it if you want to be able to defeat it.

Some iteration is required (With 100K pot I might start with 4.7K - 10K and 0.1uF or greater and iterate from there to the optimal values - best done in spice) and this approach works best over a very limited range of the listening levels, and as you would expect boost becomes significantly less as you turn the volume up.
 
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I have this one, slightly simpler - I also cannot tell you its origin: (when I saw the useful circuit I just saved it with no record of where it came from)

It should be easy enough - using simulation software - to plot the frequency response curves of both circuits and see which you prefer.

The tapped pot circuits are merely a cheap approximation anyway, so no reason they are inherently better than an arrangement using a standard pot, other than they may give a lower insertion loss.

There are also circuits that use double-gang pots, so for stereo you'd need a four-gang, or two gear-coupled twin-gangs.
Hi Steerpike!
Where is the simulation of this circuit?
At the output of this circuit can be eaten added OA (operational amplifier) IC= NE5532 with gain 2 ... 5dB?:confused:
thank you!
 
I have this one, slightly simpler - I also cannot tell you its origin: (when I saw the useful circuit I just saved it with no record of where it came from)

It should be easy enough - using simulation software - to plot the frequency response curves of both circuits and see which you prefer.

The tapped pot circuits are merely a cheap approximation anyway, so no reason they are inherently better than an arrangement using a standard pot, other than they may give a lower insertion loss.

There are also circuits that use double-gang pots, so for stereo you'd need a four-gang, or two gear-coupled twin-gangs.
Hi
Where is the simulation of this circuit?
At the output of this circuit can be eaten added OA (operational amplifier) IC= NE5532 with gain 2 ... 5dB?:confused:
thank you!
 
Hi
Where is the simulation of this circuit?
At the output of this circuit can be eaten added OA (operational amplifier) IC= NE5532 with gain 2 ... 5dB?:confused:
thank you!

Simulation I have not done, you'd have to do that for yourself using one of the free Spice programs out there.

Certainly an op-amp with any gain you wish can be added to the output.
 
Resurecting and OLD thread about the use of Loudness control with a non-tapped potentiometer, here's a simple design that works just fine.
Of course, if needed, you can modify the values to suit the situation accordingly.
It also makes the volume control into a Logrithmic taper, which is nicer to have.
SimpleLoudness.jpg