Good evening guys,

About a month ago, We set up a customer with 8 Klipsch CA-800T's in bypass mode, powered by 4 ea Niles SI-2150's. The customer wanted Pandora/Sonos as the source, and it is controlled by his iPhone. Sonos out loops to first bus input, and loop through to each amp, etc, and then put to a pair of woofers. The Niles amps are being triggered on by the Music Sense trigger.

Two and a half weeks ago, customer calls and says amp 3 is turning off. I get a replacement coming and swap it out. All good, right.

Today, Amps 1 & 3 in our stack are going in to protection mode after about 1/2 hr - 1 hr. Amp 3 goes before amp 1. I verified volume levels, reset the amps, and sat down to listen. Everything sounded great. Come back in an hour after working in the house and both amp 1 and 3 are in protect mode again.

Call tech support. They give me the whole ra ra about no known issues on the amps, etc. Oh wait, Sonos? There's a known issue for a few weeks about the Sonos outputs being "too hot" going into Niles amps. Known to who? Tech support only. I asked them where the tech bulletin is on the issue. Oh, we are working on getting it to the web.

At this point, I am very frustrated with them and their products. He proceeds to tell me that I can send an email to tech support about getting a tech bulletin published. I volley back that I am in the field troubleshooting, and being he is sitting at a desk he can send an email for me! "I didn't build it, I am only in tech support, I am not an engineer" song and dance follows.

Anyone else have a similar set up and getting similar results?

PS Original amp has been received by them for 2 weeks per UPS tracking, and still has not made it to the bench for testing. I was told today turn around is normally 4-6 weeks!!

Hmmmm? I have been hearing some distortion from a ZP90/Connect1 (whatever) for some time. I finally changed from fixed to variable volume and lowered the output that way. It seems to have helped. Did you try that or would it work in your system?

It is already on variable, otherwise you wouldn't be able to change volume on the Sonos app.

I've done a LOT of sonos with external amps, never had an issue with output levels. That said, if the audio is not audibly distorted, the amp should not be going into protect mode, no matter how "hot" the input signal is. My guess is that the speakers are dipping low in impedance and pulling too much current from the amp. The speakers are rated "8 Ohms (4.5 min @ 167Hz)"

I'd check the wiring impedance too, water in a conduit pipe can saturate the wire jacket and cause lots of bizzare issues.

Wiring is all ran overhead from ceiling above a suspended ceiling through hangars. No conduit or chance of water.

I guess our next step would be to get an ohm-meter out and check each speaker line.

+1

Has anyone ever found a solution to this problem as I am having the same issue with a sonos systen and niles Si-2150 amps

Are you guys using the input sensitivity controls on these amps to set the level, or just setting them at Maximum? If you decrease the level, you're not losing anything, you're just increasing the input voltage required to develop full output. If the sensitivity is too high, it will eventually clip and/or overheat, especially if the output from the iPhone/Android isn't limited.

Use the optical and run it through a DAC

It would have been great if the original poster would have followed up, to let us know what he found or did to solve the issue.

My money is on the Niles amplifiers. I don't like them and I bet the original poster solved his problems by swapping them out.

Sonance amps all the way!!

Two identical Niles setups. No one else has seen it with any other outboard amp. Problems with that one amp, but I just wonder what technically could cause it.

I the input signal is too hot, it will overdrive that stage when it's not able to handle that level. Some have more headroom than others- he should contact Niles about this.

Hello all! Our solution to this problem was to remove the SI-1250 amplifiers and replace them with Parasound units. We never had a problem again with the Parasounds. We have been using them the last few years with great success.

Then there should have been audible distortion.