Recent content by sleazymamba

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    Denon PMA-600NE

    Hi everyone. From experience, would this amp be a good match for Diamond 9.1 speakers with a sub ? I like natural sound, not too shouty, not too bright in the upper mids, airy highs with solid bass but not overbearing. Usually listen at 70-80db. Currently running a Technics SU-A700 mk 3 which is...
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    Mains hum from subwoofer

    I was using hashed together RCA cables with banana plugs screwed on to the centre conductors, grounded outer sleeves, plugged into the speaker level inputs (not the RCA inputs). Just to see if providing some sort of shielding would make a noticeable difference, like a poor man's shielded speaker...
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    Mains hum from subwoofer

    OK so after much mucking about I seem to have a solution. Not an answer, but a solution. First of all I grounded the amp to an earth pin in a mains plug (nothing else connected, no fuse, just earth). Made no difference. However I'll leave it connected. Then I made up a set of test cables using...
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    Mains hum from subwoofer

    Ok thanks I'll give that a try. Probably connect a lead to an earth pin on a mains plug (leaving the other pins disconnected) and shove it in the wall. If it doesn't work, or not completely, I'll try the cables. I guess I can ground the shield to the same point as it won't be part of the audio...
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    Mains hum from subwoofer

    Thanks. I have a feeling that AnalogSteph is bang on the money. I just need to understand how best to ground the amp.
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    Mains hum from subwoofer

    Forgive me but I don't understand. If it still produces hum when the cables are disconnected from the amp and hanging in air, where is the circuit to create the loop ?
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    Mains hum from subwoofer

    Fair point. Because the power switch is round the back at the bottom, and the sub has an auto-off feature that doesn't work because it thinks the hum is a signal so it never shuts off. I was hoping to let it turn itself on and off as needed. Interestingly the problem persists when the cables...
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    Mains hum from subwoofer

    Thanks for replying. The SU-A700 has a grounding terminal on the back which is currently unused. No other ground terminals that I can see, and the mains supply is non-earthed. Should I connect this to something, and if so what ? Mains earth ? Water pipe ? The only other component apart from the...
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    Mains hum from subwoofer

    Hi, I have recently purchased a Wharfedale SW-150 subwoofer which is being driven by my old Technics SU-A700 MK3 amp. Very happy with it. However I am getting a pronounced and clearly noticeable mains hum when the Technics amp is powered off. The subwoofer is connected from my amplifier “B”...
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