Dillen
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You didn’t tell us where you used the wirewound resistors?
Geoff, are you here, listening?
I wonder if you could find a few words to say about this,
– why, do you think, Bang & Olufsen never addressed any of these, seemingly serious,
issues in any of their passive speaker models and is it, perhaps, something that will
be taken into consideration when you develop and design new speaker models for B&O?Martin
- Thank you. You did a fine job yourself, takes Alot of patience. Yes, I painted the frames satin black to match the cones. I rebuilt crossovers with film caps and wire-wound resistors. I also machined and phase-plugged the midranges, as well as foamed the inner baskets frames for ultimate clarity. I’m running them in conjunction with a rebuilt Polk RM-1000 subwoofer and custom tpa3255 amp to match aesthetically. Pure audio bliss.
I find this interesting,
– a few questions if you don’t mind:Wire-wound resistors – where?
“machined and phase-plugged the midranges”
What is that, exactly ?
Is that the cone shaped thingy? If so, can you tell what improvement this provides?“Foamed the inner baskets frames for ultimate clarity”
Interesting, – what is the theory behind this?
And do you have any before and after values that would cast light onto what improvement this provides?Martin
No relay click when you select a source?
Front panel correctly fitted? – If the bronze forks under the front panel does not grip
each their little pin on the circuit board, the touch fields will not work.Martin
Something shorted?
Which transistors did you replace?
How did they measure wrong?
And what did you fit instead?Martin
Sure you got the tracking angle correct?
I think it looks very steep.Martin
Make sure the whole motor assy hangs free in its spring supports.
The motors metal bracket must not touch the nylon bushings (or metal carrier
bracket depending on version) anywhere (in normal playing position),
or you will experience exactly what you describe.Martin
Why not have the Beogram repaired?
It’s a nice deck, and they are all repairable.Martin
It would not.
They are very different. Beogram 5000 opens all the way to the back and is opened at the push of a button by spring tension.Martin
The felt pad is most likely from a cassette tape.
Inside every tape cassette, on the reverse side of the tape, is a felt pad to press the tape up against the tapehead while playing.
I don’t recognize the spring.Martin
The spring has lost its tension.
Take it out and twist it from both ends towards the center to add more tension.Martin
The component designation depends on the exact type of Beogram 4002.
0TR4 in some versions.
1IC4 in other versions.
Etc.Martin
Could be a bad relay.
There are two, found on the large tape controller board under the turntable.Martin
But it doesn’t start event if I’m on CD mode.
Still normal.
Press CD instead, – and it will also close the door if open.
Same as with all other B&O CD players.
MartinBeocord 2000 prototype in palisander veneer.
Plus other minor differences:
Martin
Burned output stage.
Not a job for an untrained – with all due respect. Repairs like this can give even highly
skilled tech guys a good run for their money.Put short – replace everything from the differential amplifier outwards.
Then power up slowly using a variac while keeping an eye on the idle current and DC offset. Follow up with adjusting the idle.Martin
I found also that when i put CD and close a door it is not starting reading the disc, I need to push CD button
That’s normal. Closing the CD door should not be reason to f.e. switch from radio, or what else is playing, to CD.
Pressing CD, on the other hand, should.
MartinThanks for the photo.
They are bipolar.
Some also have the word “Bipolar” printed across the cap at the “positive” end. Perhaps
visible if you rotate them a little.
Used heavily in B&O passive speakers.
The polarity marks merely indicates which pin is connected to the caps metal house.
But replace them – they will be out of spec by now.Martin
Should the unit operate without the aluminum covers in place?
Yes.Does the wood trim need to be pushed in to operate?
No.Can the fuses be tested or replaced?
Both. But some tech skills are required, and a fuse rarely blows for no reason.What type of fuses are needed?
Depends on the exact version of Beogram 4004 – there are several.Martin
They should definitely be bipolar!
Are you sure you are not just seeing marks indicating which pin is connected to the caps alu housing (for shielding purposes in some applications)?
That can sometimes confuse.
Photo?– But they would need replacing anyways due to age.
Martin
