Hissing sound coming from tweeters

SS ammplifiers and sometimes preamplifiers can have a hi noise floor most never hear it because designers thought only low or average efficiency loudspeakers would be used. And most do such. But if using horns on SS it can be hard to find a low noise SS design. I do know NAD newer bee amplifiers are horn friendly and affordable. I design loudspeakers and trust me SS amplifiers can have more noise on horns than tube amplifiers.

Have you tried cheater plugs on the amps? Works sometimes.

The amps have a 5 year transferable warranty. Maybe you can contact Emotiva and see if they will ship you another one to try - just in case it is something wrong with your amps. Or they may have suggestions to try. I have been reading the Emotiva board and a small number of people do seem to have hiss/hum problems - not common but certainly some reports of issues.

Lots of good thoughts above. Given that the 89db s/n number is referenced to 1 watt (as opposed to full power), I would expect that with 101 db speakers it would result in a hiss level that can be heard at a typical listening distance in a quiet room, but not to a degree that is "very annoying." Even if the number is based on A-weighting, which would de-emphasize high frequency hiss somewhat.

However the very high 32db gain, in combination with the 101 db speakers, means that the noise level that is heard will be extremely sensitive to any noise that is picked up or introduced at the input circuits of the amp, including rfi/emi (radio frequency interference/electromagnetic interference) that may be picked up through the air. Are the amps located away from other components? Are the interconnect cables routed so that they do not run close to and in parallel with other cables or power cords? Are there any fluorescent lights, dimmer switches, computers, or other known rfi generators in the vicinity? If so, try turning them off.

Another contributing factor, btw, which can't be helped, is that your ears are only 25 years old, which means greater sensitivity to high frequency hiss than most of us would have :-)

Regards,
-- Al

It could be your system is not grounded properly. Our cable company, comcast was doing work and and did not properly ground the system. I was having hissing through the tweeters also. To pinpoint I disconnected the cable into the preamp and the hissing stopped.