I have a small 8" sub which only has low level inputs, it doesn't have any unusual hum with nothing connected but as soon as you connect it to an amp's pre-out it gets a rather loud and noticeable hum.
I've tried 3 different amps and all have the same outcome but if I connect a cellphone headphone output to it it works as expected so I'm assuming it's a earth loop issue.
According to my plug point tester the plug in the wall is correctly wired with earth connected and the amp and sub are connected to the same plug point.
What is the next step?
Albeit risky will removing the subs earth connection help?
2 of the amps I tried used 2 core power cables without a ground, I'm not sure how that affects things. Touching the metal body of the amp did somewhat reduce the hum in the sub, not completely though.
I've tried 3 different amps and all have the same outcome but if I connect a cellphone headphone output to it it works as expected so I'm assuming it's a earth loop issue.
According to my plug point tester the plug in the wall is correctly wired with earth connected and the amp and sub are connected to the same plug point.
What is the next step?
Albeit risky will removing the subs earth connection help?
2 of the amps I tried used 2 core power cables without a ground, I'm not sure how that affects things. Touching the metal body of the amp did somewhat reduce the hum in the sub, not completely though.
