Can someone help me with this peculiar issue?
I replaced a cheap 100K Ohm volume pot on an tube amplifier kit with a 100K Ohm Alps Blue Velvet volume pot. With the Alps volume control at the extreme ends, near the most quiet and near the most loud, I get a slight hum with a noise, a sort of rushing sound.
Between those extremes the Alps volume control is dead quiet.
The original cheap volume pot had a similar issue but less pronounced.
This was an S5 Electronics K12G kit. I did remove two 0.22uf DC blocking caps in line with the two inputs.
I replaced a cheap 100K Ohm volume pot on an tube amplifier kit with a 100K Ohm Alps Blue Velvet volume pot. With the Alps volume control at the extreme ends, near the most quiet and near the most loud, I get a slight hum with a noise, a sort of rushing sound.
Between those extremes the Alps volume control is dead quiet.
The original cheap volume pot had a similar issue but less pronounced.
This was an S5 Electronics K12G kit. I did remove two 0.22uf DC blocking caps in line with the two inputs.
You might have an oscillation problem, as well as a ground issue. The residual resistance of the Alps in both extreme positions is only a few tens of an ohm, unlike cheap pots where it's 10x more, which may account for the less pronounced effect with the cheap pot. For an experiment try connecting a ~1k resitor in series getween the pot wiper and the amp input, and report what happens.
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