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
B&O receivers are not really regarded high in the reviews in vintage audio forums.However it seemed that the old ones like the Beomaster 3000 en Beomaster 4000 were not bad at all.I also love the design, the 3000 was released in 1969 and it still looks great.I have quite a lot of amps form the seventies but this 3000 somehow looks timeless.Yes it is 45 years old but it is still a joy to look at.I personally like the design more then my 2 years old home theater receiver.The wooden case is one of the best of all receivers I own (most vintage Japanese)There are wonderful vintage amps and receivers that put many nowadays amps to shameAfter I received the Beomaster 3000 my first listen was a pleasant surprise.There was a however little crackling that popped up when there was a silent passage.After soldering a loose contact that was gone.The amps is remarkable quite, even with the volume at 10 there is hardly noise and no hum.In this one the 3 big capacitors were not leaking and they also had even more capacity then marked.I also got a 4000, in these the biggest cap was heavenly leaking, something I never saw in a Japanese amp.Then the famous orange caps. I read that many say you should replace them.If they show leakage or measure less then I would indeed agree to exchange them.Also check the shell, if you see micro cracks, exchange. If they however seem to be ok, I suggest to keep them in.I think they are excellent for audio.I even think they are one of the reasons why I love the sound of the 3000.In mine I exchanged the BC208B for BC548B (NOS in still owned).Not that it think that a transistor will get worse due to aging but these 2 somehow were not sounding as good as the new BC548B (they generated some shrillness in highs sometimes).After changing the high were smoother, and i tested by first changing one channel and compareto the other so I do not think it was my mind playing with me.Then I adjusted the Bias with the ampere meter like in the manual.Beware the variable resistors do not work well after all these years (at least one in mine did not make contact all the time and I exchanged it).After the bias was set I started to listen and there was an improvement much more then several Japanse amps that I serviced.Might have been due to the bad variable resistors in it but the 3000 sounded now wonderful.Great bass, beautiful mids and smooth and lovely highs with nice details.This receiver now sounds as good as it looks.You can listen for hours and there is no fatigue at all.It sounds very realistic and voices are great.After servicing the 3000 blows many amps that are regarded high in the forums out of the water.For those saying that B&O is more design then sound they should listen to the old models.The 3000 now belongs to the most pleasurable sounding receivers I own or owned.
nongrata:There are wonderful vintage amps and receivers that put many nowadays amps to shame
Welcome to the believers !
Watch out for the Beovirus!
//Bo.A long list...
Maybe a BC548 is a much better transistor to use in the layout of a BM3000, it takes a bit more current but maybe the BC208 is too closely dimensioned for his job, together with readjusting the Bias could be the main reason why its sounding a lot easier now.
Congrats on your fine sounding BM3000!
"Believe nothing you read and only half of what you see, let your ears tell you the truth."
Chris indeed the BC548B can handle more voltage and can handle more watts then the BC208B.In a way it is a successor.Probably new they were ok for the job but the first generation silicium transistors sometimes can cause some trouble.First they start to sound a little shrill in the highs when there are for instance loud rock guitars.Then they also get noisy and later they start to crackle.Not sure should look into the specs but if I remember well the BC549B is the low noise version of the BC548B so might even have been more suitable.But as i have a lot of NOS BC548B lying around I grabbed that one.
Hello
Thank you for this analysis I also own a BM 3000 and a BM 4000 which I agree offer a special design although the keyboard can de headache sometimes.
I like to improve the sounding and had the same feeling regarding the highs sometime a bit too much present. Could not find this 208 on mine can you please tell me which TR references are concerned?
Alain
Hello Alain
First of all mine is to be correct a Beomaster 3000-2 2402If you have a different series be careful as the description might not be valid.Problem with B&O is that they did not write on the component side like the Japanese did.As example no TR12 or R234 written on the PCB.Also the service manual is a puzzle as they use 7 digit numbers for transistors and then you see in a tablefor some 4 or 5 transistors (but are equivalents).To make it even worse they use different 7 digit numbers for several models.So I try to give you some directions for an easy find,The amplifier board (the one with the many orange capacitors) go to the side were the wires go to the power transistors and were you see the 4 round silver transistors with star shaped coolings.I am doing this from memory but am quite sure I am right.You see the variable resistors (green transistor next to it) for the bias and now go down in a line to theorange capacitors and in the middle you see a transistor next to a another one which is a big round silver one.If they look like a small grey round water tower and there is BC208B on the side you have found them.There just a handful of transistors on the amp board and if the problem is not solved by changing the BC208 you could try others too.If you see any BC147 or BC148 these also might cause trouble as these are also older generation.So check for transistors that do not have the regular shape you see nowadays as these are theones that get out of spec during the years.Also be sure to adjust the Bias according to the manual.If you need to find the points were to attached the ampere meter let me know as the manual describes nice how to adjust but were it is located on the board you need to search a lot in the manual.Then check the 3 big caps near the transformer.The 2 smaller ones on the sides are decoupling caps for the speaker outputs and if they have lost capacity or (worse) leak they can influence the sound also a lot.
Hello,
Thank you for the detailed answer.
As ar as model is concerned mine is 3000 without -2 but very similar to the 3000-2. All electrolytic caps changed including the "three big"
Bias current adjusted to the recommended value
What is new for me is transistors subject to aging as with the tubes.
I found the transistors you mentioned as BC 208 and will have a try for change and report eventual improvements to the actual sounding which is not so bad!
Cheers
Found two of these "water tower" BC114 as per TR39 and TR 53, replaced with what I had 548 and 550 C.
Sound improved in the highs. In addition no more scratch noise when using HI and LO filter but I do not know why.
Good to hear that it worked.
Enjoy the sound of the Beomaster in a way it was intended to be by the manufacturer when new.
Ciao
Alex
Congrats +1