Vinyl Line-In to Era 100 - Poor Quality except when Left or Right is Disconnected

  • 23 October 2023
  • 13 replies

Hello internet people,

So I recently bought the Era 100 hoping that in addition to steaming WiFi music (which I have no problem with) I could use this speaker to play and stream my vinyl (to the other Era 100 I bought for another room). 

Before you ask, yes I have a dedicated phono preamp which sounds great with my amplifier to tower speaker setup I’ve used for years. The turntable and preamp (from my audiophile days) are a ClearAudio Concept and Graham Slee Era Gold phono preamp. From the preamp, this connects with RCA cables to an RCA to 3.5mm splitter to the Sonos proprietary 3.5mm aux to USB-C cable. 

The sound is ghost-like, for lack of a better word. It’s barely audible (but can be heard). At extremely high volumes, the power line buzz is overwhelming and audio is still whispers of music. I’ve troubleshooted this with Sonos (which was a waste of everyone’s time), consulted numerous forums, tried numerous different preamps, tried increasing the source level. Nothing worked. Then I noticed something truly bizarre. 

In one of my tests, I had the audio playing and turntable spinning with only one of the RCA cables plugged in (left or right, don’t remember) and the sound was good. It was far from hifi (and far from what Tidal streaming from the Era 100s is capable of) but it was at the appropriate volume and generally sounded like music. Then I plugged in the other RCA cable and the sound immediately cut out and went back to ghost mode. It’s almost like there’s a short circuit or some sort of destructive interference that is canceling out the music. 

I’ve read plenty of posts about users not having phono preamps or needing to adjust the source level (neither of which is my issue) but has anyone seen an issue where RCA to USB-C on an Era 100 works only when one channel is disconnected? Anyone have any idea what is causing this or how to fix it?

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13 replies

Don’t be afraid to check the silly. I’m curious about that dual RCA to 3.5mm adapter. Make sure it is stereo and fully seated in its Jack. I assume that you have tried all combinations of one preamp output to adapter combinations. If you have an Ohmmeter, check the dual RCA to 3.5mm adapter.

Try another analog source.

Thanks Buzz. I have tried two different RCA splitters. Same result. Both both work fine in a TV-out to different amplifier application. 

Oh and Sonos sent me a new USB-C to aux to confirm it wasn’t that cable - same result. I also tried a generic USB-C to RCA (non-Sonos proprietary). That cable resulted in no sound. The Era did not recognize it as a line-in device (probably due to the proprietary cable issue). 

I confirmed that plugging my phone into the aux works fine with the Era 100 which is frustrating because the issue persists with my record player, which works fine on a different set of amplifier/speakers.  

When you plug only one turntable output into the USB adapter, does it matter which input Jack you use? Does it matter which turntable output is used?

When you play the turntable through a receiver are you using a “PHONO” input?

Is the turntable grounded to the preamp?

Thanks buzz. Doesn’t seem to matter if I use left or right. Yes, preamp is grounded to the turntable. There is a distinctive hum, despite the fact that it’s grounded. When I short the left and right cables together (make them touch) that is similar to the sound I hear when the system is plugged in. 

I’ve tried using a preamp with multiple inputs, one is a phono input (my cartridge is a moving magnet, as is the input stage) and this gives the poor quality/buzz. I also have tried several phono dedicated preamps and get a similar result. have some shorting plugs, experiment with replacing input to the USB adapter and preamp with the plugs. Is there any hum?

The hum starts when the preamp is powered on. Yet, when I connect this preamp to my other amp/speaker combo, there is no hum and quality is great. 

Are shorting plugs inserted into the preamp’s input?

Hi buzz, I don’t totally understand your question. But I did some more investigating. If I have all 4 RCA cables (L / R into preamp and L / R out of preamp into Sonos) I get the low quality sound and buzz. If I only disconnect either the L or R from the out of the preamp it sounds good. While single channel output, if I disconnect one of the input channels (either L or R, doesn’t matter) the sound degrades substantially. It’s as if there’s some sort of grounding or channel interference happening where the two channels sum to a single aux cable at the aux to USB-C connector at the Sonos. 

Unfortunately my preamp does not have a 3.5 mm out (so I can’t test to see if that would resolve the issue). I don’t necessarily want to buy another preamp and spend more money on this, since I know my preamp works with my other amp/tower speaker setup, so I can’t understand why it doesn’t work on the Sonos. 

As its name implies a “shorting plug” is a short circuit — a null input if you like. There should be very little or no buzz.

If possible, cycle through reversing each power plug in its socket. This may reduce the buzz.

Your reduced level issue is consistent with using a mono 3.5mm to RCA adapter.

@sleevel i’m having the exact same issue with my era 100. audio sounds fine with only one of the L/R connected to the 3.5mm adapter, but when both are plugged in it seems to warp the audio somehow. did you ever figure out how to fix?

This is the sort of connection you should be using. Make sure that all pugs are fully seated in their socket.