[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.

• This reply was modified 2 weeks, 6 days ago by LeHe.

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[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.

 

[LeHe]

Have you activated the automatic recalibrated system of your speakers so that the power amplifiers set themselves to the correct power value using the internal software circuit in relation to the speaker microphone. If the calibrated system detects troubles in the hardware it wil let you now with led colors so I read in the user manual.

[LeHe]

You are a silver member. Look at the service manual in the database of schematics, it already includes two schematics. one without ( date 11-1991) and one with ABL.( date 03-93 ) printed on de pages, including other PCB layout.

Furthermore what I have noticed, B&O works with alphabetical revision nummers printed on the PCB by changes, such as ‘PCB partnummer’  Rev N and also with version nummers with a number behind the PCB part number like ‘6142169(0) ~ ver 0’

[LeHe]

Light noise can have many causes. First clean en check the Box and PCB’s on damage, also the components.

Because on photo 5505 I see sloppy and incompletely mounted white damping material, but also old parts of black decayded material on the right side. I think someone just schoved some new stuff in there, without actually removing the old material and cleaning the units.

Because in photo 5512 I only see old decayded black material that is also touching te PCB and components.

From serie nummer 10145230 onwards, they are provided with ABL

Clean and inspect it and then take the following steps to fix the light noise, if it has maybe already disappeared then.

[LeHe]

The first thing you need to do is set the basic setting correctly according to the factory instructions below.

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[LeHe]

I have given my Beolabs 6000 serial number 140….. a Maintenance service, sound was ‘good’ .

When removing the speaker cloth, nothing seemed to be wrong, but as soon as you touched the woofer rubber suspension, it completely crumbled. totally perished.

Then I removed the woofers speakers to look at the condition of the internal damping material, but not only after that, also at the air density of the seal of the speakers between themselves and at the aluminum housing. ( Previously I renovated a Beolab 8000 whose damping and sealing material was completely decayed. what a sticky thing. PCB was affected there.) With the BeoLab 6000, the quality of the damping material was equivalent, so completely perished. Only with the Beolab 6000 is the damping material partially glued to the housing, so it cannot sink towards the PCB as with the Beolab 8000.

But still, small pieces had ended up on the circuit board and connectors, which could have caused damage in the long run.

Also, damping material completely removed, including the mutual sealing edges and completely renewed.

Because the rubber suspension of the speakers was also completely broken, these speakers also replaced (you can only replace the defective rubber suspension instead of renewing, but I have opted for total replacement.)

For the coming years, the quality feeling and the sound, especially the midrange and the bass are sublime again.

[LeHe]

The service manual described the steps to take when the led is green and the speakers are silent.

Become a silver member and you will get access to the service manual.

 

 

 

 

 

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