What is this horrible noise when plugging in RCA cables
dan98svt
Posts: 83
I have a Kenwood KM 208 amp with KC 208 pre-amp. When I plug in the RCA to the amp, I get very loud low-end feedback through my Polk SDAs. I can twist the RCA connector a bit left and right and make it stop, but it takes a while to find the right spot. This happens on both channels (both plugs). Once it's set up, it's good until I have to unplug it for some reason. Is this a grounding issue inside the amp? Is it fixable (without a degree in rocket science)?
Thanks,
Dan
Thanks,
Dan
Comments
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Either your cables are bad or the RCA jacks on your amp are. Try different cables, if the problem goes away then you know it's the original cables. If the problem remains, it's the amp and time for a trip to the amp doc.Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
Just to check, you are plugging the cables in with all gear turned off, right?Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
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Just to check, you are plugging the cables in with all gear turned off, right?
As the read what the OP had written that was my 1st thought.
Because I am The Pumpkinking
A Kind Word Is An Easy Gift To Give -
Just to check, you are plugging the cables in with all gear turned off, right?
It would be dead silent if that was the case.
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Like Jesse mentioned.....I had a similar problem with a Carver TFM-35. The RCA connector ground solder connection broke free from the board. The RCA connector was a block assembly, like these. Might be worth a look inside to see. Of course power off, unplug and remember caps can hold a charge and they can shock you should you touch the wrong things inside the open chassis.
What folks have mentioned, it's not clear from your post if you are hot connecting or just twisting connectors after you power on. Hot connecting is a bad idea with an RCA connector as the hot center pin connects before the ground barrel connection does.
Just a little history info, the Lemo Camac connector, like Mark Levinson and others used on their gear, connected ground before hot. That connector didn't catch on so to speak, the RCA dominated. I still wouldn't hot-plug components with any type connector.
RCA to Camac adapters.
Salk SoundScape 8's * Audio Research Reference 3 * Bottlehead Eros Phono * Park's Audio Budgie SUT * Krell KSA-250 * Harmonic Technology Pro 9+ * Signature Series Sonore Music Server w/Deux PS * Roon * Gustard R26 DAC / Singxer SU-6 DDC * Heavy Plinth Lenco L75 Idler Drive * AA MG-1 Linear Air Bearing Arm * AT33PTG/II & Denon 103R * Richard Gray 600S * NHT B-12d subs * GIK Acoustic Treatments * Sennheiser HD650 * -
I had a bad sub connector on a old Sony ,everything was playing just fine then out of the blue loud nasty hum and touch the cable made it go away, shut it down right away, then when inspecting it I could feel the wobble in the connector.2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge
HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD -
I always plug inn my stuff with the amp off. When I turned it back on (after moving it all), it buzz/hummed like crazy. I had to adjust (twist) the RCAs a little until the noise stopped. It's good for now, but I'll pop the cover off sometime to check the connectors from the inside.
Thanks for the replies.
Dan -
Just to be clear, everything needs to be off, the pre too. Which RCA cables are you using ?HT SYSTEM-
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's -
I'm using regular red/white 3' cables. Tried different sets, all with the same noisy result. It's something internal. I can make it stop, but only when powered up so I can find the sweet spot...
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Those red and white cables are junk bro. Buy some decent cables, Signal cable analog 2's or Bluejeans cable.....about as cheap as you can go for decent interconnects. Or order some from Douglas connections, he's a member here. Solid build and not expensive.HT SYSTEM-
Sony 850c 4k
Pioneer elite vhx 21
Sony 4k BRP
SVS SB-2000
Polk Sig. 20's
Polk FX500 surrounds
Cables-
Acoustic zen Satori speaker cables
Acoustic zen Matrix 2 IC's
Wireworld eclipse 7 ic's
Audio metallurgy ga-o digital cable
Kitchen
Sonos zp90
Grant Fidelity tube dac
B&k 1420
lsi 9's
