albert
Junior Member
Living in Sthwst Florida
Posts: 68 
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Post by albert on Feb 2, 2019 23:41:16 GMT
My AMI f120 was modded before I got it. it is mostly original with the old amp still installed but disconnected. an old radio shack stereo amp (very small) was installed and a stereo cartridge installed. I repaired power supply all crumbling cables and have the mech working including coin slot. They installed a white flat ribbon cable (4 conductor) from the tone arm cartridge all the way to the amp. I installed a small stereo amp after removing the radio shack amp. It has a separate output for the base speaker. So its left/right horns and center base. I get a hum that I reduced by adding ground wires to everything. I think I need to get a shielded tone arm cable and wire my cartridge to be Mono from cartridge to amp. what do you think. I select a song and it plays great and loud without the preamp I bought. (cheap) but hum still there. it plays with me as I touch that thin ribbon cable. a fifteen foot shielded mono cable is 35 bucks and I just don't want to throw money away on this. All I need is about seven feet. Thanks. Albert.
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Post by Ron Rich on Feb 3, 2019 0:45:16 GMT
Albert,
PLEASE--add your location as requested in our User Introduction section ! Is the cable you are using shielded separately, or is the shield being used as a wire for the ground ? Ron Rich
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albert
Junior Member
Living in Sthwst Florida
Posts: 68
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Post by albert on Feb 3, 2019 1:30:07 GMT
there is no shield. just 4 wires on a flat white ribbon cable. right/ground and left ground. I want to use a mono cable and connect both grounds to ground and right left together to audio input. I think if I use a shielded mono cable I will eliminate the hum and can split the line in to the amp. my profile shows i'm from florida.
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Post by Ron Rich on Feb 3, 2019 14:06:47 GMT
Hi Albert,
My thought was to use the shield as a drain, rather then a ground ??
Yes, that's what it says in your profile, but it's not shown in your posts, as it is not in either your "status", nor "signature area" as requested, in our introduction sticky. Ron Rich
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albert
Junior Member
Living in Sthwst Florida
Posts: 68
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Post by albert on Feb 3, 2019 16:50:29 GMT
I'm looking for it to fill it out?  ? |
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albert
Junior Member
Living in Sthwst Florida
Posts: 68
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Post by albert on Feb 3, 2019 17:03:54 GMT
It has 2 wires covered by a soft braided shield. by drain do you mean clamping down the shield material to the tonearm and then also the other end to the amplifier chassis?
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Post by Ron Rich on Feb 3, 2019 18:39:37 GMT
Hi Albert,
No--a "shield" is tied to chassis ground on one end ONLY--usually on the amp end ! Ron Rich
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albert
Junior Member
Living in Sthwst Florida
Posts: 68
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Post by albert on Feb 3, 2019 21:50:45 GMT
Oh, ok thanks ron... now gotta wait for new wire. will keep you posted.
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