Connect:Amp Direct Line Input Delay to Wired Speakers

Hello Sonos,
For the past few years I've used the line input on a Connect:Amp to power a left and right wired speaker with no issues. Recently, I started to notice a clear and obvious major delay from the line input source to the wired speakers. I do not have any other Sonos speakers connected wirelessly.

I originally thought this was from my computer or a USB preamp I have for conference calls, but if I test the actual wired input (1/8" male jack from my computer headphone out to RCA left/right male in to the Connect:Amp) simply by touching the input to hear a buzz...there is now a 5 second delay to the wired speakers. This was not the case for 5+ years and just started happening about 3 weeks ago.

I should note that streaming music from Apple Music or Spotify has no delay...I can press start and stop and the music stops immediately and pairs with other Sonos Play:1 and 3's I have. Only when I use the line input directly to the wired speakers is there an issue.

Is there a new firmware patch that could have caused this issue?

I recently purchased a brand new Connect:Amp to see if it was a hardware problem with the one I have that is 5 years old...same exact issue right out of the box.

Thank you so much for any suggestions you have.

Best answer by ratty 2 October 2019, 16:28

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23 replies

Change the Line-In compression setting to Uncompressed. It sounds like it's on Automatic and, for some reason, has decided to apply compression.

Settings -> System -> Audio Compression
This may not apply, but one other additional thought, just to add to what @ratty has mentioned above, is perhaps to also ensure that ‘AirPlay Device’ has not been selected as the Line-In ‘Source Name‘ as that also will increase the Line in audio buffer and delay the output.

Such selected ‘source names’ chosen, can be custom named also, so it may pay just to check that aspect.
'AiirPlay Device' would be consistent with a 0.5s delay, rather than 5s.
That’s why I mentioned it was just to ‘add’ to your suggestion @ratty.

Thank you Ratty and Ken for both of your support. 

100% fixed now after changing the compression to “Uncompressed”.  Woo hoo! 

I’m so pumped it’s back to normal now! 


Change the Line-In compression setting to Uncompressed. It sounds like it's on Automatic and, for some reason, has decided to apply compression.

Settings -> System -> Audio Compression


Just wanted to see about this myself. Same scenario - running a Connect Amp for many years without issues. I just did a reset on the device when I added it to another system and I’m getting a delay on my system regardless of Automatic, Uncompressed, or Compressed - about three seconds.

It was working fine without delay (analog ins) before I:

Reset the system
Added a new Sonos ONE to the system. (Removing it didn’t change anything).

The new SonosONE is not grouped either - but when I do group then - it’s in sync - also 3 seconds behind.

I’m curious if adding a new device to the system is the issue? Even ungrouped?


There is a current bug causing this. Behaves like compressed when set to uncompressed.  Sonos are working on a fix. 

I’m having the same issue after years of trouble-free use. I’ve had to unplug my Play 5 (2nd Gen) stereo pair from the TV and go back to using built-in audio 😞

Sonos, PLEASE get this issue resolved ASAP 🙏

There is a current bug causing this. Behaves like compressed when set to uncompressed.  Sonos are working on a fix. 

Is this bug invoked on its own somehow, or only if someone has toggled from one to the other? I thought the latter, that only if one has toggled away from uncompressed, toggling back to it isn't successful. Could be wrong though.

And it is applied to the entire system; so does the setting get disturbed if any unit in the system is factory reset?


I’ve opened a case with a diagnostic - (01447263) - but support is asking me to start from scratch on troubleshooting whereas I’m asking them to validate that this is a known issue. I’ve been “okay” with the 70ms delay - what I’m not okay with is the 3-5 second delay that is now being introduced after years with it working as designed.



I am in a similar situation. Noticed that my Play 5 Gen 1 has a 3 Second delay. It is connected to a laptop using a line-in. Another bug I noticed that the line-in now default to a Sonos 1 I have. I have manually change to the Play 5 everytime. Hopefully they can release a patch soon.




Any further news from Sonos on this? 🙏

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HI everyone, with the 10.6.2 update today, this should be fixed. There are also some new settings that you can use with your line-in to adjust the delay (still a minimum of 75 ms). Make sure you’ve set the line-in to uncompressed, and you can pick your delay now.

Thank you so much for this excellent news! I can confirm that this update has restored the ability to bringing down the delay to the acceptable 75ms for AV setups 👏


I see that the IOS app has been updated to 10.6.2 - but my system is still on 10.6.1 and checking for an update states “Your Sonos system is up to date.” - was 10.6.2 back end pulled? Or do I need to be patient?



That’s odd, I got my iOS update already. When you look in the Apple App Store, what version do you see? You have to click on “version history” to see the version data.

If you see 10.6.2, but it won’t update automatically for you, feel free to delete your current version from your iOS device, and download the new one. Just be sure to “connect to existing system” when you start it.

I am just south of you in Texas, I’d think we’re both connecting to the same iOS store, and mine does say 10.6.2. 


I have iOS 10.6.2. But my Sonos is still on 10.6.1. 

Deleting the app from my phone and reinstalling doesn’t help…

I tried the same on a second Sonos system with a 10.6.2 controller and 10.6.1 speaker and it doesn’t pull a new update either… I’ll open another ticket...

I have the same issue. That said, the IOS App update alone has fixed the issue with setting of uncompressed Audio and bringing the delay back to 75ms...

I’d imagine the 10.6.2 firmware update would have been applied to only the devices that needed it, i.e. devices with a line in, and the remaining speakers, such as the Sonos One would not get updated with the minor update. I’d expect when 10.7 comes out, all speakers would get that. I’ve seen in the past where my PLAYBAR got a dot update, and the rest of my speakers didn’t, but I didn’t have any issues in using my system. 

Are you having a particular issue with your system, or are you just looking around in your “About My Sonos”?


Bruce - appreciate your efforts to help. I was trying to show a screenshot that showed my controller and system in one screen shot even though it wasn’t a connect - all of my devices are on 10.6.1. But this is my Connect details:



In my history of devices - I’ve never seen a controller have a different version than the speakers and not have a prompted update be provided. I’ll be able to review my second system with a Connect this weekend and validate if only the Controller update fixes the latency. If it’s something where an API wasn’t setting the “uncompressed” setting correctly - that would totally make sense why an IOS update would fix the issue. :)

Please report back. I know for sure in the past my devices have been on multiple ‘revs’ of the firmware. Just not sure about this pass, as I don’t have a CONNECT in my system to confirm. 


I flipped every setting and it’s still lagging 2-3 seconds. This iOS update didn’t fix it as expressed earlier. Going to update my existing ticket (new diag 1330262007). Would love to be able to just use an older version at this point...


Haven’t heard back from support in five days since I sent the diagnostics. Pinging then again...