[LeHe]

Here in the Netherlands you can still subscribe for two fixed analog connections. Those connections are integrated in the home modem for internet and Wifi and are offered for many years. So I connect my still in use home exchange with Becom 6000 and Becom 2 units to call everyone for dinner and such, even good friends know the regular old numbers, just in case. Nice equipement also.

[LeHe]

@Johan van der kallen

The capacitor of 1 nF now added by someone op the PCB like the foto is parallel or instead placed over the by factory installed C130 capacitor of 1 nF in the PCB version with ABL. This capacitor is then normally mounted on the top of the PCB, you can check whether he is gone, it may never there, then you have a PCB version without ABL (serial numbers below 10145230), the first one’s. Someone was experimenting with your speaker before and update that capacitor is was not there in the version without ABL but is was in de ABL version..

Have you all cleaned all the contacts and is there no more popping or crackling anymore when you switch or remove the line in plug.

Because if they go into standby with a shorted input, they should also do the same with a open input (without line-in cable connected) If that works to next step, source en the power line-in cable. Shut off the source and plug the line-in cable into the speaker, if he then hums or otherwise makes noises, then your line-in cable picks that up somewhere ( Sources of interference in the area, pour cable quality, aging, ground corrosion) and will not switch to standby. Test then with a short good cable near the source, good luck.

The action @jacek1313 has taken is actually symptom control, a custom made speaker for that situation,  it is better to eliminate it at the source, but that is not always possible and this is then an option too.

 

@jacek1313

Thanks for the feedback; no problems with a switching off speaker during longer soft passages in the music ?

[LeHe]

On what calculation did you determine the capacity or did you just try this out on the basis ‘ Tray on error’ .

Have you with this value no problems with a switching off speaker during longer soft passages in the music.

[LeHe]

It looks like Beobuddy has an STL file that he used to print the white version at the beginning of this article.

So ask him to provide it.

The black one in the same picture next to the white is the injection-molding machine version from the supplier I mentioned earlier

[LeHe]

Ok, certainly true, but who will make the STL file first, still seems more expensive than simply buy 2 print holders for € 40,-  for that one time or it has to be about numbers (business)

[LeHe]

For most people who overhaul their own Beolab 8000 once it seems to me more convenient and much cheaper to just buy a new holder, versus the cost of purchasing a 3D printer or commissioning someone who has one and who first has to create an STL file

 

[LeHe]

Stephan, ( Ich werde auf Englisch antworten, damit jeder es lesen und/oder kommentieren kann.)

You are a silver member, so you can view the data of the bolab 4 yourself via products>beolab>beolab4.

I don’t think you will find somewhere else a specific repair to the applier PCB nor the specific electronic diagram.

The power amplifier is just an IC with some components added, with some knowledge of the matter it is not that difficult to repair, otherwise find someone who can or buy a new output stage print from B&O.

What is broken that you want to repair. ?

[LeHe]

That popping sound comes from dirty contacts of the connections and of the switches. This is an age-related phenomenon of corrosion and dust. Insert and remove the Line in plug several times en make several switches without voltage on the unit so that the contacts clean themselves reasonably well again. Put the power on and test it until its gone, otherwise you need contactcleaner from some store.

If you short the line input and the speaker is silent, will the speaker switch to red standby after about 2 minutes ?

If so then you have a problem with the power line in cable from the transmitter, it could be grounding, poor contact as discussed earlier.

If not, then the speaker itself has an electronic problem that needs to be looked at.

On the back there is only one 3 step switch with the combination function left-Right for power link operation and line in selection for the Line in plug. And yes if you choose line in the transmitter cable determines what is playing left or richt channel or whatever.

 

LeHe

[LeHe]

If you disconnect the RCA line input does the speaker go into standby or if you then short the RCA line input, what does the speaker do.

If there is ambient or preamp noise with is picked up by the RCA line-in cable or comes from the preamp the speaker stays online and does not go into standby. The speaker already switches on at a signal of circa 870 micro volts.

Or does the speaker hum slightly when online status with could indicate a bad grounding., because of that hum it does not switch off in standby.

 

[LeHe]

Jaspers1996,

You can buy them for your Beolab 8000 at http://www.dksoundparts.com ( circa € 20,- a piece)

[LeHe]

I have been in contact with B&O Denmark. They only release are the basis schematics and PCB02 layout for the MK1 of 1991, in the version without and with ABL with other Woofers. All documentation of mutations after that date are only accessible to the dealer, read themselves.

These modifications are mainly layout adjustments of the PCB02 for small additions such as extra capacities for decoupling and layout adjustments due to other component dimensions in the years, with makes it seem as if the PCB02 and therefore also the schematic has changed completely. But 99 procent is still the same as the basis schematic of 1991.

Al possible defect are easy to trace with that basis scheme from 1991 and modifications play no role in that, only then you have to trace the components on a custom PCB02 of that serial number.

[LeHe]

Came across this old post.

This modification was also applied ex works to my 1995 1155 xxxx speakers. ( same construction)

Checking the PCB02 schematic shows that this capacitor 4.7 uF has been applied as an additional interference suppression and smoothing on the negative supply of – 15 volts.

I think that de reason for this modification was discovered during the final test of the product. Maybe interference or voltage dips.

So leave it as it was  or rebuild it. The manufacturer did this for a reason and is not a hobbyist’s invention.

Attachments:

You must be logged in to view attached files.

[LeHe]

To get the last serial numbers more accurately.

My BeoLab Mk1 serial numbers 1547 xxxx have already the newer (white) foam in the housing and under the amplifier print.

The other like sealing tape for the housing and the wiring harness protection are still fitted with the old sticky black insulation strips.

 

[LeHe]

Even if it would really fit with a few adjustments, then still, the power range and characteristic of the speakers is to different.

In power alone I think it is a factor 1:4 (25 to 100 Watts)

Beolab 8000 wil also sound very different based on yield and one time the volume level too high at the Beolab 8000  and the Beolab 2000 speaker also runs out the coil, that the scratching more worst is then the old one.

Fitting is a matter of measuring or try on error, but the technical specs are  to different.

[LeHe]

Open it and see if the PCB’s has been affected by the black damping material. If so clean and repair the PCB’s.

If repairing ready or if no black damping material ( the series from about 2000 had new white damping foam ) then you will have to do some measurements with a multimeter. If you have one and still have a little knowledge of the subject, I can guide you further in de repair process, if not look for a local electronic hobby man or go to the Dealer.

No sound actually means a power problem +/- 50 volt for the power amplifier. Do you hear the internal relais switching on any moment.

[LeHe]

The connector for audio from the input terminals is P4 on PCB02 with B&O code 7220710 connector plug 3 pole ( see page 19-1 of the service Manual)

For the original you can simply order it through a B&O dealer. (Last production date about year 2010, 10 years obligation to deliver, who knows old stock).

These connectors were commercially available 35 years ago when the Beolab 8000 were designed. So there is a little chance that the same ones are still available. But I see several similar ones on Aliexpress and Amazon.

[LeHe]

Beolab 6000 woofers unfortunately have a specific design specially made for this speaker box, speaker frame glued and molded into a custom holder. Replacing it with a normal speaker that requires you to adjust the mounting plate seems almost impossible to me. Also I don’t think they are available with a suitable size en power range and impedance, the reason that B&O had them specially produced.

If you so quite handy as you say, just provide them with new rubber edges, total material cost maybe € 30,-

Otherwise it will simply be € 350,- for 4 brand-new speakers or used ones on Ebay refurbished by someone else for less than half  that amount.

 

 

 

 

[LeHe]

Guy

I entered the code but there is no difference.

Maybe it is not a Mk2, serial number is 15734840 and it is from 1997.

Is there another method-solution ?

 

Thanks

[LeHe]

I read in the service manual that the tweeter impedance should be 6,6 ohm and not 3 ohm as you specify as good !

[LeHe]

Following steps: I mean in my case,( but I have measuring devices for that),is to follow the signal from the output or input and determine where extra sound (noise) is added to an proper or blank signal. Then additional electronic analysis at that spot in the electronic diagram is needed to find out what is causing it, so that it can be repaired.

Not everyone has that measuring devices and knowledge and that is why many people simply replace all the electrolytic capacitors in the signal path, sometimes with results but very often not at all.

 

[Author]

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