Help with hiss
Hello Friends,
My speakers have developed an audible hiss that I am trying to chase down. The hiss can be heard from across the room and while music is being played. Sometimes, the hiss is pulsating and sometimes constant. It occurs at all hours, perhaps less so in the early morning. Sometimes there is no hiss at all and everything is silent. It is an intermittent issue that is unpredictable.
My speakers are powered by mono block amplifiers. Both speakers exhibit the exact same behavior. The monos are plugged directly into the wall outlet. I also plugged them into a PS Audio AV Power Center with no relief. I changed power cords with no relief. No other piece of gear is on, although all are plugged in and some are in standby. I turned one mono off of course stopping the hiss in that speaker. The other continued to hiss. In reverse, same result.
This is not a “hum” (like from a ground loop). It is the same hiss that you can hear with your ear next to the tweeter but much louder.
I’m happy to answer any questions at all to help me resolve this. Thank you in advance.
OP:
Well, I don't mean to suggest any cable brand is particularly good or bad, I was just wondering if you'd made a change that could account for it. Right now it looks like you have to go up the food chain, but keep en eye out for any wall warts. They still generate noise even when the load is off. |
A couple of things to try.. first, re-route all cables making sure that the low level cables (interconnects) are at 90deg to any power cable they need to cross. Make sure speaker cables are kept away from power cables.
If that doesn't help, turn everything off, disconnect any interconnect to the mono blocks and then turn them on. If you still hear the hiss, then it's from the amps. If you don't, then connect the interconnects but do not turn on the preamp. If hiss, then it's the connection (interconnects or the input of the amp). If no hiss, then connect the preamp (test first without it on and then with it on). And so on, work your way backwards until you identify the source. I went through this exercise only to find that if I plugged in my integrated amp to a different outlet on my PS Audio PowerPlant, any and all hiss went away. |
@erik_squires Oh, I did not take it that way at all!🙏🏻 I think I was trying to address the very real issue of shielded vs. unshielded. I’m not sure which of the cables are which, but it will be very easy to get that information. I’m afraid my Brick Wall is loaded with wall warts, but there has been no recent addition, unless one is beginning to fail (which is possible). I’ll end up systematically unplugging each one and seeing if that has an effect. I don’t want to jinx it, but since I got up on this quiet Sunday morning, the system is absolutely silent. I’m thinking you guys may have scared away the gremlin!! He knew I called in the big guns! |
@audiojan Thank you so much for that! I do what I can to route the cables that way. It’s quite a mess back there without a lot of room to spread things out like they should be. I am cognizant of it, though. I will also do as you suggest and disconnect the interconnect to the amp. I agree that isolating the amp from the rest of the system may provide some answers or direction. |
@forestg Wrote:
Just a thought, the Loki does have a wall wart style power supply. The two most common reasons for hiss is either a grounding issue or a gain staging issue. I know this may sound silly but my guess is check the amplifier bias, maybe it's drifting, causing the hiss. Wish I could be of more help. See Odyssey Audio below: Mike https://odysseyaudio.com/kismet-reference-amplifiers/
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