BS9000 + BL3 = buzzing and high pitched noise

[BeoHound9000]

Long time member, first time posting on the new forum:

I have a recently serviced BS9000 connected to BL3s. At the moment its one cable per speaker, not daisy chained. There is a high pitched tone coming from both speakers from all sources and even when muted. Also, one speaker makes a digital chirping sound whenever the volume, track, or source is changed, but only one speaker (with the aftermarket cable).

I’ve read that cables not rated for Mk3 speakers will do this. One cable is OEM from my BL8002 and other is from an aftermarket company in the Netherlands and marketed as compatible with BeoLab 3s.

I don’t have my 8002 here to test with. If the PowerLink cable from Vintage Bang & Olufsen in NL is the problem, I could see that. But what ‘s curious is that even the PowerLink cable from my 8002 is creating the tone (if it is the cable).

I’m curious to hear thoughts and theories. Thank you!

 

[trackbeo]

Block diagram shows the two Powerlink outputs are simply wired in parallel on the BS9000.  So noise generated by a faulty speaker *might* propagate to the other cable, regardless of whether they are daisy-chained or not — it’s just a dumb bus, not separate output drivers.  Start by disconnecting the aftermarket MK.2 (thick, 8-wire) cable and set it aside.  Then test: Run the BS9000 with just one BL3 at a time, and use the MK.3 (thin, 4-wire incl. ground/shield) cable for that single speaker.  You’ll quickly discover if one speaker is whining, or the BS9000 is.  Don’t forget to try both channels with each single speaker, using the L/R switch.

(N.B. I have never personally experienced a high-pitched whine, only the well-known click&buzz when the volume control was pressed, from using 8-wire cables.)

[Edit: You might also try plugging in headphones and see if your whine sounds on them.  Not sure what that result would mean, but someone else will know.]

[BeoHound9000]

Thank you for your replies. The results of my tests are not encouraging:

I tried each PowerLink cable on its own and between the two PowerLink ports. I also used headphones through the minijack at the bottom.

With headphones everything sounds normal. The high pitched tone remains and the digital chirp only seems to be in the left most PowerLink port.

I should mention that this equipment came with me from Europe, so its all 220V running on step up voltage convertors. I’ve even tried these in different outlets and plugged them into noise suppressing surge protectors.

It sounds like the 9000 needs to go back unless this is a common problem with 220V B&O equipment on voltage boosters?

[Millemissen]

If the problem is only in one of the PL outputs – you wrote ‘the left most PowerLink port’ – you could try to use a powerlink splitter from the other one.

MM

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