Hard to say but the IC1 belong to the circuit that turn on the amplifier when the input signal reach a threshold level.
It may solve your problem if you swap the IC1.
Carl
Your problem certainly sounds exactly like the same problem I had. I bet you need to change IC1 and this will fix the problem. I used an IC1 chip from an old unit but earlier in the thread is some alternative you can buy. You need a solder blow gun to remove the old IC, be careful to not rip off the solder pads.
I wasn’t aware that you had these requirements you mention above. I have looked everywhere and can’t find how to upgrade to a gold membership nor how much it cost and how to pay?
I have now made an initial sound test between the original Beolab4000 and the rebuild version with the Sonos built in amplifier. The result is very positive! It is a dramatically improvement with the Sonos amp! The sound is much more open, this is specially present with the voices. The bass is more precise and nuanced in the rebuilded speakers.
You calibrate the rebuild speaker with Sonos Trueplay which is included in the Sonos app for Iphone and Android. The speaker play a frequency sweep which the phone pick up and adjust the speaker for a flat frequency response.
Just to be clear, no Beolab 4000 drivers are present. The Beolab 4000 speaker elements are direct connected to the Sonos amplifier and all is 100% integrated in the Beolab 4000 cabinet.
The kit include an Ikea Symfonisk amplifier and electronics (which is made by Sonos). This consist of a very powerful DSP which will calibrate the Beolab 4000 speakers to a flat frequency spectrum and a multiroom wifi active two way speaker.
They sound extremely good, I will try to make a comparison with the original and come back. With the Sonos trueplay calibration, the frequency range will be flat.
