noise

maingey
maingey Posts: 632
edited November 2005 in Electronics
need help,
I just hooked up a parasound hca806 to my onkyo 989 avr..i bridged it down to 4 channels, but am only usiing 3... well, now I have a noisy hum, and can't figure it out......I can hear it with nothing playing, but I can turn it down by adjusting the vol level on each channel, but it's still their... what is it and what to do about it?
Post edited by maingey on
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  • beardog03
    beardog03 Posts: 5,550
    edited November 2005
    ground loop maybe
    could also be your I/C`s

    Swap your interconnects around one at a time, and see if you find a bad/noisy one

    what do you mean "bridged it down" ?
    Cary SLP-98L F1 DC Pre Amp (Jag Blue)
    Parasound HCA-3500
    Cary Audio V12 amp (Jag Red)
    Polk Audio Xm Reciever (Autographed by THE MAN Himself) :cool:
    Magnum Dynalab MD-102 Analog Tuna
    Jolida JD-100 CDP
    Polk Audio LSi9 Speaks (ebony)
    SVS PC-Ultra Sub
    AQ Bedrock Speaker Cables (Bi-Wired)
    MIT Shotgun S1 I/C`s
    AQ Black Thunder Sub Cables
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    Magnum Dynalab ST-2 FM Antenna
    Sanus Cherry wood Speak Stands
    Adona AV45CS3 / 3 Tier Rack (Black /Gold)

    :cool:
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  • adam2434
    adam2434 Posts: 995
    edited November 2005
    When I had a hum, it was a ground loop that I eliminated by using a 3 prong to 2 prong adapter (cheater plug) on my amps power cords.


    I've also read that these types of ground loops can be caused by cable TV. I think you can buy ground loop isolators for cable.
    5.1 and 2.0 ch Basement Media Room: Outlaw 975/Emotiva DC-1/Rotel RB-1582 MKII/Rotel RB-1552/Audiosource Amp 3/Polk LS90, CS400i, FX500i/Outlaw X-12, LFM-1/JVD DLA-HD250/Da-Lite 100" HCCV/Sony ES BDP/Sonos Connect. DC-1/RB-1582 MKII/Sonos Connect also feed Polk 7C in garage or Dayton IO655 on patio.
    2.1 ch Basement Gym: Denon AVR-2807/Klipsch Forte I or NHT SB2/JBL SUB 550P x 2/Chromecast Audio.
    2.0 ch Living Room: Rotel RX-1052/Emotiva DC-1/Klipsch RF-7 III/Sony ES BDP/LG 65" LED.
    2.0 ch Semi-portable: Klipsch Powergate/NHT SB3/Chromecast Audio.
    Kitchen: Sonos Play5.
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  • maingey
    maingey Posts: 632
    edited November 2005
    It's a six channel amp, channel 5 and 6 bridged for front left, 3 and 4 to front right, and channel 2 to center.... I didn't realize I couldn't bridge the first two channels so I'm stuck with a little less power from the center.......
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  • maingey
    maingey Posts: 632
    edited November 2005
    I have the all units plugged into a monster htr 3500 surge power jammie, the parasound is on a switched outlet, so when I power the avr(onkyo) it triggers the parasound. THere is a radio shack not too far away, so I'll run out and ask (ps I did check the interconnects to the amp, all the other analog interconnects have always been without interference)
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  • F1nut
    F1nut Posts: 50,779
    edited November 2005
    Never plug a power amp into a switched or unswitched outlet on a receiver. Those outlets are not designed to handle the demands of power amps.
    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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  • maingey
    maingey Posts: 632
    edited November 2005
    the power amp is plugged into a switched outlet on the monster htr 3500 not the avr
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  • maingey
    maingey Posts: 632
    edited November 2005
    i got the three to two plug adaptor, plugged the new amp into one then plugged it into the htr3500, no help... I disconnected the cable from the cable box, and believe it or not, the noise got a lot louder!(cable still running thru the htr3500 filter before getting to the cable box..... I can say that it is a little quiter than last nite, and more prevalent in the front left adn center speaker than the right.... still lost.... I asked at radio shack tonite for a ground loop isolator and no one had a clue... can someone tell me what it looks like?
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  • McLoki
    McLoki Posts: 5,231
    edited November 2005
    Have you called Parasound about it?

    I have a 6 channel Cinepro that ended up with a hum and I was able to call the company that purchased Cinepro when they went out of business and was able to solve my hum issue. (was an easy fix from home so I did not have to send in my amp)

    Just a thought.

    Michael
    Mains.............Polk LSi15 (Cherry)
    Center............Polk LSiC (Crossover upgraded)
    Surrounds.......Polk LSi7 (Gloss Black - wood sides removed and crossovers upgraded)
    Subwoofers.....SVS 25-31 CS+ and PC+ (both 20hz tune)
    Pre\Pro...........NAD T163 (Modded with LM4562 opamps)
    Amplifier.........Cinepro 3k6 (6-channel, 500wpc@4ohms)
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  • maingey
    maingey Posts: 632
    edited November 2005
    Ya, today, spoke to a guy named TOny. Said it was prob a ground loop or blamed the cable for the prob...he also interrogated me about the amp because it's been discontinued for a few years, but I told him about me just buying it and opening the sealed box myself....
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  • adam2434
    adam2434 Posts: 995
    edited November 2005
    Have you tried completely disconnecting your cable TV by unplugging it from your Monster line conditioner? You may also want to try to put the 2 prong adapter on the Monster just for kicks.

    If unplugging the cable eliminates the hum, then it would appear that your cable TV is the problem and an isolation transformer would be a good thing to try.

    Here's a cheap one from Parts Express.

    [URL=http://]http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=180-075[/URL]

    I've also seen a $100 one at Audioadvisor.com, however, the ad for it says that it is not compatible with digital cable or satellite. Don't know if the Parts Express one would have the same compatibility issue. My guess is that the transformer messes up the digital bit stream.

    Good Luck
    5.1 and 2.0 ch Basement Media Room: Outlaw 975/Emotiva DC-1/Rotel RB-1582 MKII/Rotel RB-1552/Audiosource Amp 3/Polk LS90, CS400i, FX500i/Outlaw X-12, LFM-1/JVD DLA-HD250/Da-Lite 100" HCCV/Sony ES BDP/Sonos Connect. DC-1/RB-1582 MKII/Sonos Connect also feed Polk 7C in garage or Dayton IO655 on patio.
    2.1 ch Basement Gym: Denon AVR-2807/Klipsch Forte I or NHT SB2/JBL SUB 550P x 2/Chromecast Audio.
    2.0 ch Living Room: Rotel RX-1052/Emotiva DC-1/Klipsch RF-7 III/Sony ES BDP/LG 65" LED.
    2.0 ch Semi-portable: Klipsch Powergate/NHT SB3/Chromecast Audio.
    Kitchen: Sonos Play5.
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  • maingey
    maingey Posts: 632
    edited November 2005
    can't mess it up too badly, all signals hiccup constantly on that cable box, annoying as all heck.... thanks for the renewed suggestions... I called radio shack but they had no such item... damn them!!
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  • Holydoc
    Holydoc Posts: 1,048
    edited November 2005
    Maingey,

    You can read about ground loop problems here:

    http://www.audioholics.com/techtips/setup/avhardware/groundloopcableTV.php

    A very nice ground loop eliminator for digital tv cables is here:

    http://www.21best.com/21_best/electronic/security/video/filters/for_sale_.html#HUMplug

    The cheap one that I got for my HT is here:

    http://www.bluejeanscable.com/store/rf/rfprices.htm

    Good Luck!
    Holydoc (Home Theatre Lover)
    __________________________________________
    Panasonic -50PX600U 50" Plasma
    Onkyo -TX-NR901 Receiver
    Oppo -Oppo 980HD Universal DVD Player
    Outlaw -770 (7x200watt) Amplifier
    PolkAudio - RTi12 (Left and Right)
    PolkAudio - CSi5 (Center)
    PolkAudio - FXi3 (Back and Surround)
    SVS - PB-12/Plus (Subwoofer)
    Bluejean Cables - Interconnects
    Logitech Harmony 880 - Remote
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