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).
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).
Attachments
Something like this?
http://www.diyaudio.com/forums/solid-state/154209-reverse-old-loudness-control-4.html#post1982010
Also check the latest posts in that thread, starting with this one:
http://www.diyaudio.com/forums/solid-state/154209-reverse-old-loudness-control-8.html#post2292435
... but I haven't seen a way to do it passively. If there was, it would have been done that way from the beginning to avoid the extra cost of tapped pots.
http://www.diyaudio.com/forums/solid-state/154209-reverse-old-loudness-control-4.html#post1982010
Also check the latest posts in that thread, starting with this one:
http://www.diyaudio.com/forums/solid-state/154209-reverse-old-loudness-control-8.html#post2292435
... but I haven't seen a way to do it passively. If there was, it would have been done that way from the beginning to avoid the extra cost of tapped pots.
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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.
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.
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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Seems like passive circuit is not the best solution. May be someone can suggest active one with 12AX7 or6N1P for example (I have them anyway already)?
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?😕
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?😕
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.
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.
similar approaches are realized here:
http://www.dl4cs.de/audio/preamps/loudness/index.htm
Unfortunately this isn't a level independent approach - exact like those versions with tapped potentiometers.
This is a great disadvantage for the use of loudness filter - mostly the equalizing effect is clearly too strong due too much output levels of several line-level sources like a lot of cd players.
Therefore I like the variable and level independent loudness potentiometers like in use on Yamaha's AX-570.
check out also this thread:
https://www.diyaudio.com/community/threads/loudness-circuit-modify-pot.364258/
http://www.dl4cs.de/audio/preamps/loudness/index.htm
Unfortunately this isn't a level independent approach - exact like those versions with tapped potentiometers.
This is a great disadvantage for the use of loudness filter - mostly the equalizing effect is clearly too strong due too much output levels of several line-level sources like a lot of cd players.
Therefore I like the variable and level independent loudness potentiometers like in use on Yamaha's AX-570.
check out also this thread:
https://www.diyaudio.com/community/threads/loudness-circuit-modify-pot.364258/
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Just a Newby intuitive thought... If you used a 24 or more position rotary switch with resistors, couldn't you simply take a tap at any point you wanted?