Kingdeezie

Stephen, Thanks for the feedback. The Pass 350.8 is a hold-over from my previous speakers. They sound excellent but require the power. I knew I was going to have to eventually replace it as 350 watts is overkill. My system was quiet as a tomb before. Zero noise. I didn’t anticipate the 17 DB increase in efficiency would bring issues. I intend to keep the La Scalas, just will need to sort the amplifier situation out sooner rather than later.

What defective component would cause the same exact sound/level of hiss through both speakers? Called Pass and believe I spoke with Kent. Very helpful. Wanted me to short the cables to isolate the amplifier output to see if the hiss was still there. Much like you described above. He thought, given the 105 DB efficiency, that hearing hiss from a short distance (inches) away might not be unreasonable. Ironically “downgraded” to the LaScalas to simplify my life and just start enjoying the hobby instead of obsessing. Now down another rabbit hole. Thanks for the help all.

Thanks for the suggestions! I tried the amplifier with nothing plugged in to it and the hiss was still present. I don’t think there is a way for the user to turn down the input gain, I would likely have to send the amplifier back to pass. As long as the hiss isn’t harmful I don’t know if I’d be pumped to send 150 pound (double boxed up) amp back and forth from the factory. Too expensive and risky for a quieter noise floor. I’m just assuming that the amplifier wasn’t made for something that efficient. My whole system was dead quiet before with speakers that were 88/1 watt. The combo does sound good.

Thanks everyone for the input. I’ll start looking in to amplifiers that will be a little quieter.

Thank you for the feedback. I haven’t listened today but just did some quick testing. Hiss is there with just the amplifier on (nothing hooked up to it). Hiss seems slightly louder when preamp is hooked up and on also. Hiss is audible right on top of speakers, less noticeable at 1M, barely perceptible at listening position. When I’m up on the speakers with my ear right on the horn, I hear a very slight hum. I guess this could be a ground loop but it quickly drops off when moving away from the speaker. Hiss doesn’t seem to change with volume. When music/movies/games are coming through the speakers I don’t hear anything but the signal. I doubt it’s the speakers. At 105 DB per watt I think a mosquito farting near the speaker cables would be audible. My last speakers were 88 DB per watt, so it’s quite the delta in efficiency. Just haven’t heard any noise like this with this equipment.

Hello Klipsch Community, I just received a pair of LaScala AL5s in American Walnut. I am simplifying my set-up and wanted something with a known history of reliability and quality. Only have like 15 hours on them and have done minimal placement work, but WOW! I can actually enjoy all of my recordings! I noticed one problem last night however. When I was turning off the system and got closer to the speakers with nothing playing, I could hear a “hiss” or a “white noise” coming equally from both speakers. Having heard it now, with nothing playing, I can’t un-hear it. It’s faintly audible like 7-8 feet away on axis. I muted the preamp and still heard it, which I think means it’s not before the preamp’s input stage. I think it might be my amplifier. It’s a Pass 350.8. Complete overkill for a speaker that is 105 DB, but I have to sell my old speakers to recoup some cash before changing. The odd thing is when I first plugged the LaScalas in, I don’t think I heard it. Yesterday I played the system for 10 hours straight, so maybe it’s thermal noise from the Pass? Internet searches don’t bring much clarity. I guess my questions for the community here are: 1) Has anyone experienced this before with any of the Heritage high efficiency designs? 2) Is the noise potentially damaging to the speakers? 3) How can I rectify the issue? I thought that Pass amplifiers had a low noise floor. It never was a problem before with my normal 88-92 DB speakers. Thanks all. Overall really happy so far with joining the Heritage family.