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Originally Posted by Postal_Blue /img/forum/go_quote.gif
It is almost certainly channel imbalance in your pot. You need to get further into the sweep of the pot most/all pots have the most imbalance issues at the lowest volume.
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That sounds right
Quote:
Originally Posted by Postal_Blue /img/forum/go_quote.gif
A voltage divider on the input may be the best solution, or you could try output resisters as suggested by Germania.
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Two poor options
Quote:
Originally Posted by tomb /img/forum/go_quote.gif
With the SSMH, Dsavitsk's and rds's method of using input resistors prior to the pot seem very helpful. I can't detect any downside, either - at least on the PCB version.
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Here's why and how this works, and why it is a better solution.
Generally, the load seen by the previous stage is a pot, which is an adjustable resistor divider to ground. At low volumes, the output can be pictorially though of as being closer to ground with the top resistor being larger, and at full volume, it is at the top.
Putting the resistor in front of the pot essentially elongates the top resistor of the divider pair. If, for instance, you have a 50K pot with a 50K resistor in front of it, you now have a 100K pot where the wiper, which sets the divisor's ratio, can only travel up half the length of the wiper. It also changes the divided ratio such that the same setting on the pot will yield less signal to the first stage of the amplifier. There is also some argument that it improves the quality of the resistor that is in the signal path, so actually sounds better than all but the best pots.
The full effect is that if you turn the amp all the way up, you have 50/50 divisor that sends, at most, half the signal to the amp when, with a normal pot only you would sent 100%. 50% of the signal is 6dB, which, for most instances is incidental. A 6db difference, especially at high volume, is almost inaudible. If you don't believe this, measure a normal log pot to find the point where it is 6dB down. It will likely be higher than you would ever turn up the amp.