amplifier noise

Discussion in 'Archived Threads 2001-2004' started by Rob Rodier, Aug 25, 2002.

  1. Rob Rodier

    Rob Rodier Supporting Actor

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    I guess when it rains it pours. Seems like a recent influx with these questions.

    Anyway I have a Kinergetics Chiro c-200 and there is a very low level hiss that can be heard through the speakers. I disconnected the feeds from the amp and it is still there. This is not audible when listening but still bothersome as most of you can imagine. I am wondering if a; this is a problem with the amp and b; if there is an easy remedy. I am a student and have a limited budget so any tweaks would be great. I was also wondering about line filters like the adcoms, panamax etc. Could these cure my problem. I would need to do it @ or around $200 and have no problem buying used. Thanks in advance

    -rob
     
  2. Gruson

    Gruson Second Unit

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    Rod, I am in the same boat.

    I have a 7.1 set up, using a Yamaha RX-v1000 receiver. I am using the 6.1 (rear center) preout from the Yamaha and running it to an old Sony receiver (acting as an amp). I then have the rear center speakers connected from the Sony's MAIN (L-R) speaker output.

    This works great but for some reason there is an awful "hissing" sound coming from the speakers. I have all of the speakers at the same dB level (used an SPL meter) but the rear centers are the only ones hissing.

    I am positive it is the Sony receiver because I connected a DVD player to it and the speakers still hiss.

    Any ideas how I can get rid of this problem?

    What 2 channel amp would you recommend I ust to drive my rear centers? I would like to keep costs under $200 as well. Parasound maybe?

    Thank you.
     
  3. Rob Rodier

    Rob Rodier Supporting Actor

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    Gruson,
    My hiss is far from "awful" but might as well be as it is really beginning to bother me. Hopefully we can get some insight.

    I also want to add that I am using very high quality cables all around.

    -rob
     
  4. Gruson

    Gruson Second Unit

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    Rod,

    I solved my problem. My Sony was in 5-channel mode and when I switched it to 2-channel mode, the hiss went away.

    I only need it in 2-channel mode, since the Sony is only driving my center rear channel.

    I also switched it to AUTO mode and there was less of a hiss.

    Is yours more of a hiss or a hum and did you ever notice it before you added your 2 channel amp? (some amps always have a hissing that you cannot avoid).
     
  5. Rob Rodier

    Rob Rodier Supporting Actor

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    Low level hiss. I have it even with the pre amp disconnected. I hope that a noise filter built into some sort of pwer strip might do the trick.

    -rob
     
  6. Chu Gai

    Chu Gai Lead Actor

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    You've asked a lot of questions and answers, recommendations in no particular order are as follows.

    First, i'm unfamiliar with the amp in question, but being as you're in Florida, maybe you picked it up at Sunshine Stereo, which I understand has closed shop. I'm not even sure if anyone still carries it in this country. If the amp has something like a volume control, you might consider turning it down a bit.
    Operating with nothing connected to the inputs is a "worst-case" scenario. One should expect that the noise generated in the power amplifier to become somewhat less when a preamp is connected to the amp's inputs. Don't rely upon your ears to tell you if it's more, less, or the same. Instead place a VOM across the amp's outputs and see what the voltages are.
    It is a fact of life that equipment generates some noise, but for properly set-up home systems, it shouldn't be audible at normal listening distance. If this isn't the case then perhaps the amp may be defective. As you've stated earlier, its not audible when listening to music so probably there's nothing wrong with your amp. The thing is, once you determine you've got a hiss, even if you can't hear it sitting down and music playing, it gnaws at you. You expect dead silence and instead of listening to the music, you instead listen to the hiss. Kind of like looking at a beautiful woman (if you're male) and focussing on the fact that she missed one hair on her leg while shaving.
    Other suggestions, and they may not be appropriate since i don't know your amp, nor are they guaranteed to work are as follows:
    still get a hiss when its on someone elses system?
    got any dimmers on the electrical lines?
    are the inputs on the amp secure...no wiggling?
    any other inputs that aren't plugged in? if so, put on a shorting plug to cap them off. Cardas and other's sell them.
    try running a wire attached to the amp over to the ground on the receptacle.

    I doubt that the hiss is coming from the power lines, assuming of course that it's not a hum. that could be checked quickly with a cheater plug. if it solves your problem, you've got a grounding problem...find the cause and put the cheater plug away...i don't recommend cheater plugs other than to diagnose problems.

    purchasing and using a good surge suppressor, and usually they come with some rfi/emi filtering capabilities is always a good idea. head on over to the tweaks section and browse the topic.
     
  7. Rob Rodier

    Rob Rodier Supporting Actor

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    Thanks a lot Chu, btw I am male and your analogy hits the nail on the head.

    I did not get the amp at Sunshine, I am new to the area, but they did sell them and their page is one of the first hits in a yahoo/google search.

    I will try the cheater plug in the morning.

    I have no dimmers and am using good interconnects that are nice and snug. (ixos gamma studio 1000)

    I am hoping that if the cheater plug is not the answer than $100 bucks or so on a used rf/emi filter might be. I can live with it, but have a pair of Platinum Solos in route and platinum is no longer in business. I want to baby them so they will last for a while, this is what worries me most. I am borrowing a rotel pre-amp from a friend and will see what that does. I also planned on picking up some of the cardas caps from AA, and will do so. Hopefully that combo plus a cheapo noise filter will do the trick. I'll keep in touch. Thanks

    -rob
     
  8. RichardMA

    RichardMA Second Unit

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  9. Nathan Cook

    Nathan Cook Agent

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    try wiggling all the connections and see if the noise changes. if so its probably a loose solder inside the amp.
     

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