Hi tuttivini,

It is possible that the humming may be caused by the circuitry in the Denon receiver.  Not all receiver pre-out sockets work well with active speakers, due to the circuit designs used.

In most cases, the noise will only appear when the receiver is in standby mode, which usually stems from the receiver disconnecting the pre-out sockets from the amplifier circuitry.  This presents the Beolab speakers with an unbalanced line input, which may cause them to switch on and pick up induced mains hum from other nearby electrical products.

Beolab 6000 is particularly sensitive to this, as they can "self oscillate" and switch themselves on when no signal is present, due to their amplifier settings.

One option is to try an unpowered audio source like an iPod with the speakers (ideally using the same cables, plus an adapter) to see if the noise is still there.  If the noise only starts when the receiver is connected, then look to the receiver for the cause.  If the noise is present with the iPod, then try better cables, also try to move any other mains wiring or electrical devices away from the speakers and audio cables.

Please let us know how you get on.

Kind regards, Steve.

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I noticed the same problem when connected to my Onkyo amp, I brought new cables the were rca one end and powerlink the other with a 5v trigger cable that connected to the zone 2. I am away travelling so don't have the link to who I brought them off, but they have been mentioned on the forum several times.

i could then set the beolabs to left or right and not rca and it stopped any hum.

toby

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Using the speakers in "Powerlink" mode (ie. with a separate trigger signal) should solve the problem, although you may find that the hum is still there while the speakers are switched on, it just goes away when they are not in use.......

Beolab 6000 and early Beolab 8000 amplifiers do have a tendency to self oscillate due to the gain settings, this was adjusted in Beolab 8000 mk.2, but as far as I know it was never changed on the 6000 through the production run.  This can cause the speakers to switch on by themselves in Line mode when no signal is present and then they will produce a low hum that is loud enough to keep the speaker switched on.

As this varies between speakers and situations, it is best to first check that you don't have interference from nearby electrical equipment that is triggering the speakers, or that there isn't a speaker fault which requires attention.

Also, a word of caution regarding trigger cables - we tested various options and the types which provide the trigger signal from the receiver can cause damage to the receiver, due to the electrical condition that the speakers place on the trigger voltage.  I spoke to Onkyo's UK Technical Support during the development process and they confirmed that their receivers are NOT suitable for directly triggering Beolab speakers in this way.  USB triggering is less problematic, but this can introduce noise onto the audio channels as the USB voltage on most devices is not constant.  Hence, providing a separate mains-derived trigger voltage is the only way that will give you a good audio performance without risk to your equipment.

If you do buy a cable that takes the trigger voltage from the receiver, please confirm that this has been tested with your model of receiver and that the seller is properly insured against any potential equipment damage that it may cause.......

Kind regards, Steve.

Steve at Sounds Heavenly wrote:

Also, a word of caution regarding trigger cables - we tested various options and the types which provide the trigger signal from the receiver can cause damage to the receiver, due to the electrical condition that the speakers place on the trigger voltage.  I spoke to Onkyo's UK Technical Support during the development process and they confirmed that their receivers are NOT suitable for directly triggering Beolab speakers in this way.  USB triggering is less problematic, but this can introduce noise onto the audio channels as the USB voltage on most devices is not constant.  Hence, providing a separate mains-derived trigger voltage is the only way that will give you a good audio performance without risk to your equipment.

If you do buy a cable that takes the trigger voltage from the receiver, please confirm that this has been tested with your model of receiver and that the seller is properly insured against any potential equipment damage that it may cause.......

 

Sorry Steve, but this is a bit (te kort door de bocht, zoals ze in holland zeggen) "harsh".

The ones who claims that the (B&O) speakers place any voltage on the trigger output, didn't have a single look at the diagrams before they made their conclusions. And certainly not at the 8000's or 6000's.

First, the triggeroutput is mostly discribed in the accompanied manual. A trigger output is meant to drive external equipment with a maximum voltage and current (eg 12V and 500mA)

Secondly, the powerlink trigger pin is only  "sensing" and draws a very little current. It doesn't place any voltage on the trigger, If you measure any voltage, then it's only a very, very small leaking current from the first transistor in series with a resistor. It can't harm or damage components.

However.The only thing that can happen is a groundloop between the ground from powersupply and the ground from the audio at the receiver. This can cause noise and/or unwanted currents between both. If this causes any damage at the receiver (which most likely will not)  then it's a lack of it's design.

I've assembled several cables and splitterboxes and they all worked without any problems. The first question I always ask for which receiver it's needed. A small voltage divider is then used to prevent unnessesary drawing current from the receiver. 

Hi Beobuddy,

Sorry for any misunderstanding.  My aim was not to be harsh (or "short sighted" from the Dutch), but to give a single, clear answer that will allow future readers on this thread to steer a safe route when using their Beolab speakers with a variety of different equipment.  Whilst in some situations, utilising the 12 volt trigger may not cause issues, this should always be done via careful testing and consultation with the receiver/amplifier manufacturer.

Representatives from Onkyo and Yamaha have both verbally advised us that they may decline to support any warranty claims if the user had directly connected Beolab speakers to the 12 volt trigger output of their products.  In both cases, I had emailed a copy of the Beolab 6000 circuit diagram (input section) to them for review.

Hence, if we are to provide a professional service with appropriate product insurance cover, we then clearly cannot recommend the use of the trigger output from these products.  As these are the two most popular brands of receivers for use with Beolab speakers across our customer base, this effectively prevents us from offering or recommending cables which use the 12 volt trigger from the receiver.

Following extensive testing and research, we have supplied over 400 cable assemblies Worldwide since 2009 using a mains-derived trigger for the speakers, without any reported problems.

If you are testing each cable with the customer's receiver (or an equivalent model), then I can understand that this may be an acceptable risk for you, but this is not one that I would wish to take on.  The main aim of my post was to make it clear to future readers of this thread that it is not a good idea to try experimenting with this at home, without support of a professional cabling provider or the equipment manufacturer.

I wish you the best for your research and I will be interested to hear of your results.

Kind regards, Steve.

hello

i' had the same noise with a bl6000 connected for rear speakers with DENON 2803 and rca cable.

Now i use this cable :