ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
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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.
Steve.
www.soundsheavenly.com
Founder of Sounds Heavenly Cables and Brand Ambassador for Bang & Olufsen
Sounds Heavenly are proud to sponsor BeoWorld!
Please check out my YouTube channel at https://youtube.com/soundsheavenlycables
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
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.......
Steve at Sounds Heavenly: 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.
hello
i' had the same noise with a bl6000 connected for rear speakers with DENON 2803 and rca cable.
Now i use this cable : http://www.av-connection.com/?PGr=1760&ML=328 and everithing is ok. no "humm", only "BOOM" whith DTS movies
but no sure than you amplifier have a trigger out.
Steve at Sounds Heavenly: 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.
Hi Steve,
This is, I think, just a general response for not willing be held responsible for the consumers experimenting. And not particularly for using B&O Beolabs.
A bit off topic: I've worked a long time ago at a repaircentre for car radios. I've seen blown units with damage you normally can't imagine that it was possible to achieve such. Clearly a customers installation fault. But even then the customers claimed for warranty.
I understand your view of perspective. But don't make it any more rocketscience then it is.
From a technical point of view, here's a part of the diagram from a BL6000.
Even if it occasionally occurs that D1 or TR1 shortens, the maximum current that will flow is 12Volt/22K= 0,5 milli-ampere. And that's far below the maximum current which can be drawn from a receivers trigger-output (500mA)
archie: i' had the same noise with a bl6000 connected for rear speakers with DENON 2803 and rca cable. Now i use this cable : http://www.av-connection.com/?PGr=1760&ML=328 and everithing is ok. no "humm", only "BOOM" whith DTS movies
This is typical example of just using the right cable. To shield or not to shield...
Thanks Beobuddy,
It is a sign of the times when we need to be careful about warranty claims and insurance.....
Many thanks for the update!
Steve at Sounds Heavenly: 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.
Do I understand correctly that you offer an external powersupply to trigger B&O based powerlink?
I can't see the difference between using a trigger output from a receiver connecting to a Beolab and connecting for instance a recordplayer to a different brand pre-amplifier. Both can work without any problems and others experience humming/noise due to wrong groundings. Then a separation coil can be used in between (as a mains derived trigger device between receiver and beolab)
Yes, we found that using an external source for the trigger signal works in every case, regardless of the brand of amplifier, country of use, model of speaker, etc. and that this is extremely resilient to a wide range of equipment fault conditions. Other solutions may work in some cases as you have suggested, but I need an answer that is resilient enough to work every time with the wide range of devices and situations that they may be used in.
From Peter Pans wonder pages
Collecting Vintage B&O is not a hobby, its a lifestyle.
These 'wonder pages' answer a lot of the questions asked on the forum!
Might be a reason to learn to read danish
MM
There is a tv - and there is a BV
Dom
2x BeoSystem 3, BeoSystem 5000, BeoSystem 6500, 2x BeoMaster 7000, 2 pair of BeoLab Penta mk2, AV 7000, Beolab 4000, BeoSound 4000, Playmaker, BeoLab 2500, S-45, S-45.2, RL-140, CX-50, C-75, 3x CX-100, 3x MCL2 link rooms, 3x Beolab 2000, M3, P2, Earset, A8 earphones, A3, 2x 4001 relay, H3, H3 ANC, H6, 2014 Audi S5 with B&O sound, and ambio
Nice example from Peter Pan, but it might not work.
In this diagram the triggerground is fed via pin 7. The problem you get with the BL6000 or BL8000, is that pin 7 isn't used.
So, if you are using an external powersupply/trigger voltage, like for instance a battery, this will not work. In case of the BL 6000/8000 it all depends in this diagram how the signalground and triggerground are related/connected. With a trigger from a receiver it can work, but with an external supply it will not. That's where Steve and I were discussing about.
The mentioned diagram from PP has to be modified using a BL3000-5000 or with Penta's. These amplifiers needs pin 4 and pin 1 triggered.
The diagram from the BL6000 where you can see that pin 7 isn't used. So you need a triggerground at the level of pin 2 (ground) which can cause all he hassle, humming and groundloops.
For the BL8000 it is the same, pin 7 isn't used.
Buy PowerLink MK 3 cable, at your B&O dealer and follow my drawing.
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https://translate.google.com/
Just make a short between pin 2 and 7 and all will be fine.
The short will also prevent the same hum you get when using the old powerlink MK1 cable with Beolabs with switching power supplies, like BL3, BL6002 and BL8002. In these speakers pin 7 is in use.
Hi guys Trigger current for active BeoLab speaker must be a maximum of 5 Volts DC
You must use the Powerlink Mk 3 cable for PowerLink connection.
AV-TRSDIN8
http://www.av-connection.com/?ML=2126
DoubleU: Just make a short between pin 2 and 7 and all will be fine.
I know.
But that's where the discussion started about using a trigger output with possible humming etc.
tuttivini: Is there also a cable from beolink to stereo rca + usb trigger? Because I don't have a trigger port on my Denon av receiver...
Is there also a cable from beolink to stereo rca + usb trigger?
Because I don't have a trigger port on my Denon av receiver...
Then create a trigger! You said you had a Denon avr1907. A quick google picture search tells me it has no USB, but it has an AC power outlet. So use that as trigger with one of those cheap iPhone chargers. It's already 5Volt so forget the zenerdiode and resistor From PP's drawing.
DoubleU: tuttivini: Is there also a cable from beolink to stereo rca + usb trigger? Because I don't have a trigger port on my Denon av receiver... Then create a trigger! You said you had a Denon avr1907. A quick google picture search tells me it has no USB, but it has an AC power outlet. So use that as trigger with one of those cheap iPhone chargers. It's already 5Volt so forget the zenerdiode and resistor From PP's drawing.
Good one
......or buy one ready -made if your electronics skills are not too great
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See many more drawings here -
http://www.hifi4all.dk/forum/forum_posts.asp?TID=32157&P%20N=1
http://www.hifi4all.dk/forum/forum_posts.asp?TID=23818&PN=1&TPN=1
If, as in the drawing is a 230 volt outlet, this could be a solution to do one phone charger that delivers 2.5 - max 5.0 volts DC current to trigger the speaker relays in on / off.
Regards Peter Pan - https://translate.google.com/
Hello again
Yes that's right. Buy PowerLink MK 3 cable, at your B&O dealer and follow my drawing.
Hey tuttivini
PowerLink Mk 2 used only for Data Link. = Speaker with dieplay and BeoLab 5
Powerlink Mk 3 The screen on the green and brown wire to ensure that no noise coming in.
I do not see what your cable is when it is not divorced ad.
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Good luck with your new hobby. ;-)
tuttivini: Peter Pan: what's the reason why I have to use pin7? Because pin 2 and pin 7 need to be soldered together, so they all function as the same ground? Isn't it enough to just use pin 2 for left and right rca ground and trigger ground?
Peter Pan: what's the reason why I have to use pin7? Because pin 2 and pin 7 need to be soldered together, so they all function as the same ground? Isn't it enough to just use pin 2 for left and right rca ground and trigger ground?
tuttivini: And p.s.: I measured the voltage, coming from a 220v to 5v dc 350mA adapter which I want to use and my multimeter says it gives 7.2v. Is this adapter usable for triggering?
And p.s.: I measured the voltage, coming from a 220v to 5v dc 350mA adapter which I want to use and my multimeter says it gives 7.2v. Is this adapter usable for triggering?
Measured with no load probably. set a resistor parallel (eg 10K)
@ tuttivini
Solder Pin 2 and Pin 7 together to ensure enough ground. Too little ground provides noise.
Trigger flow is from > 2.5 Volts DC. to < 5.0 Volts DC.
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