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
By the way, one of the red-pink bulbs has lost its colour. Is there a special paint for bulbs?
NO LEDS - I am a permanent and founding member of the no-LEDs-in-vintage-equipment club.
Jacques
Back together! A first listen with headphones is positive. I get a bit of spurious noise on one channel, below music level. Crackling noise, but not in the treble or midrange areas, I'd say below 600 Hz.
The caps underneath the pot, like Søren? When volume is zeroed, no noise at all, which eliminates the amplifiers.Switching to mono (either channel) doesn't make any difference.
The transport is not silent, but friction noise is acceptable, and inferior to spool noise (the tape slightly rubbing on the flanges). I'll have to replace that self-destructing foam! The rotation of the motor gradually makes it disappear in thin air!
By the way, has anyone got an original B&O extra spool?
Jasques, I am not really sure what you are asking of..is it a image from this direction you need ??
My re-capped M75 are my precious diamonds.
An extra spool ?, Not sure, I might, next week when a nother broken machine is arriving. I will get back to you regarding the spoolChristian
Christian Christensen: Jasques, I am not really sure what you are asking of..is it a image from this direction you need ??
Yes, thanks, and after that, where does it exit?
I have the service manual if you are looking for some particualr schemtaics.Its over 70 pages including huge foldups, so I don thave time yet to scan all of it, but can scan needed parts for you later tonight.C
Err... The black wire from the auto-stop! It goes to the switch lever on the left hand side of the control panel.
I have the manual, it is on Beoworld, but thanks!
That black cable goes under the pinchroller and end up sticking out bellow the transport joystick with a mounted pin on the end to stick to the metal frontplate as an ground cableCan take image later tonight...on my way out...
Søren Hammer:@Søren: Do I spot the B&O reel that I gave you when you visited me?
Oh yes, Søren, that is the reel, and it has already been of good use, during tests. And thank you again
Collecting Vintage B&O is not a hobby, its a lifestyle.
Checked voltage, almost spot-on at -24.2 V; it should be 25 V. After all these years!
I tried the amplifier, it sounds really good, as expected. A small Beolab 5000! And with a headphone output...
That's all for today, I have this canvas frame to do for my daughter now.
Thank you Jascues, for the information about how the cap works with the motor, that I didnt know.Working with reel to reel machines is though not new to me.Here replacing pinch roller with brand new , as I inted to have the BC2400 on first spot being used until I die :).
Here image of the cable for you
Thank you!
So Christian, have you made any progress?
Right now, there's nothing more I can do until I have ordered the new components. I have not listed them yet, but there's an awful lot of capacitors and small signal PNPs to replace. I will replace the transistors (rec. and replay boards) as advised by Frede.
The cosmetic restoration is finished, including the black cardboard strips. All screws look shiny new (I use a mix of hydrochloric acid and pure water) and the panels are cleaned.
One little flaw: I can see where the old plastic sheet was over the control panel and the paint actually looks better where it wasn't!
I have now put the Beocord back together for testing purposes.
Unfortunately, the main idler wheel's noise, which was very discrete without the box, is amplified by the wooden case.
The noise level being unacceptable, I'll have to replace the wheel with a new - or refurbished - one. Until this is done, I will do nothing else.
Jassque, can you show me a picture of what you mean by a spoolMy Becord 2400 is finished for now., sounds great, really fantastic. it didnt need any BIAS adjustment.After Christmas I will conitnuie to recap it completly.Some people might this it is not necessary. but I intend to keep this for ever and use it alot, so why now reaplace old components. replacing compnents lower the risc for future circuit collapses.
Christian
A spool?
My Beocord's heads are well worn, kaput in fact, so the sound is not fantastic!
And the noise emanating from the idler wheel is honestly unbearable. I will have it refurbished.
I think I will have to find another one, with good heads. Oh well.
spools, arnt they easy to find ?, you mentioned something about a spool earlier ?I will keep this in mind about the bad heads, Have you asked Martin ?
Christian Christensen: spools, arnt they easy to find ?, you mentioned something about a spool earlier ?I will keep this in mind about the bad heads, Have you asked Martin ?
No, not yet. Martin, are you here?
Martin, seems to be less here on Beoworld lately.Life takes people in different phases.Suggest you to send him an email from his site
http://beoparts.com/I bet he will reply quick.
C
....hmmm. btw,how have you determined that teh heads are bad ?Can you see that they are physical worned out after cleaning ?Does the playback sound bad ?Have you demagnitized the heads ?Azimuth ? do you have control of the circumstances ?Is it quality difference between record and playback ?, are you using fresch new tapes, adjusted plaback and record levels ? Bias adjustment ?Just curious :)C
I use pre-recorded tapes which I know are good. I've got three other open reel machines, a Sony and two Revoxes I have refurbished to as-new condition.
The heads are physically in bad shape, being deeply marked, and irregularly so. Perhaps the heads had been badly centered at some point or even in the factory. This happens, but is only visible after years of use. Anyway, the wear mark is about 4 mm wide, and reaches the bottom of the upper slots.
Adjusting anything with such heads is illusory and can only lead to disappointment. So far the scope has remained in its box!
Does it sound bad ?
It does, yes.
I've just tried recording. The tape is erased, but nothing is recorded onto it. The meters do work.
Could be the recording switches
I am very curious about the heads, could you proviade a close up image ?
Christian Christensen: Could be the recording switches
No, they work, contacts are fine.
Sorry, I couldn't help it. I just happened to come across this in one of the boxes. For the older B&O models using the modular plug-in boards an extender cable was available to ease servicing:
Given a donor unit for the connectors, it shouldn't be too difficult to make one up yourself if needed.
Martin
Nice one Martin!
I found the culprit. The record head is open-circuit, on both channels. How can that happen?
No wonder nothing was transferred to tape!
For these decks, this is actually not particularly unusual.
Here's the headblock. You can see both heads worn at the bottom. One channel does play fine, while the other sounds really bad (little treble) and you can see why!
Tilt was possibly misaligned at the factory.
A crackling noise on the left channel, when using headphones - line out completely bypasses the volume pot - had me look for a problem on the amplifier module. A quick look at the diagram made me suspect a bad transistor and I was right. The BC154 was leaky, and replacement with a modern PNP equivalent (BC251B) completely cured the problem.
One little thing at a time I suppose!
As you know my BC 2000 has all germanium transistors, AC 107, AC 126 etc, etc, these or their newer equivalents are expensive, any way to change to silicon TRs
Søren Mexico: As you know my BC 2000 has all germanium transistors, AC 107, AC 126 etc, etc, these or their newer equivalents are expensive, any way to change to silicon TRs?
As you know my BC 2000 has all germanium transistors, AC 107, AC 126 etc, etc, these or their newer equivalents are expensive, any way to change to silicon TRs?
I guess it is possible, but perhaps not at the snap of a finger. You should compare old diagrams to newer ones and see what B&O did when they switched over to silicon. Do you have defective ones?
chartz:I guess it is possible, but perhaps not at the snap of a finger. You should compare old diagrams to newer ones and see what B&O did when they switched over to silicon. Do you have defective ones?
Until now I didnt find any bad ones, but they will come sooner or later, the Ge cost between 3 and 7 USD a piece, where a couple of resistors and Si TR will be less than 1 USD. I will have to look into the BC 2400 circuits.
--mika