Come over to me with it.
I have about 2-3 weeks line right now, but will have a look at it when I can

Christian 

🙂 My saviour!
Tack.

I really wonder what happened today..

Beomaster 1000 has no built-in antennas.
You didn't use low-ESR capacitors - did you?
That could explain both the change in sound and eventual motorboating.

Martin

No built in antenna, I thought so. Quite sure I read it somewhere but of course investigating the matter in my own machines made me conclude there was no such thing.

No I didn't use low ESR capacitors. They were all Nichicon audio grade, KA or FG series. These are not specially low ESR I believe, and should fit these applications.
The change in sound is quite subtle, not so obvious. I don't think it is necessarily for the worse, except perhaps that treble/bass ratio changes a little bit depending on volume.

The motorboating sound was a change for worse for sure, in fact it's completely unusable now, it's not subtle - it's possibly speaker damaging bad. Maybe something with the transformer, it did make a sound like a bumblebee before.

Check that you got the polarity correct for all caps.

" treble/bass ratio changes a little bit depending on volume"  I suppose is the built-in Loudness you can hear.

Martin

Yes, I should have got the polarities right, I am quite sure. Also it worked and played beautifully for a while.

I had done all work for the day and sat down with a cup of tea, very satisfied with myself. Then I started to think about that "mystery capacitor", and realized I probably had made a mistake. This was while the Beomaster was playing (some bossa nova I think). This capacitor was not marked correctly in the schematics, and I had misunderstood it and put in a much higher F and V capacitor. Though it played so beautifully I decided to replace it with a more suitable cap, because perhaps this was the reason the radio was odd and the mystery cap seems to be involved with the radiosection. I put a more suitable cap in there instead, and then tested it - all that came out was "wowowowoo". I put back the original cap (125uF 16V), not really thinking it would make a change - which it didn't - still "wowowoo". This little operation couldn't possibly have cause the problem I think..

That was a long story - in short - it worked perfectly and then it stopped working for a reason I can't understand.

The built in Loudness, it's a step towards putting it back in original shape that I could hear this more clearly suddenly then.
Does all Beomaster 1000's have built in Loudness?

The built in loudness has a perfect match with Beovox 1000 in sensititvity and and caracter.
I would never modify  a beomaster in such way

Jeppe wrote:

Does all Beomaster 1000's have built in Loudness?

Yes.

Martin

Thank you Christian and Martin.

I didn't mean the Beomaster's Loudness should be modified in any way, I don't want them modified. Just meant that the restoration may have brought the built in Loudness back to life, because it seems there was a difference here before and after my "restoration". Sometimes perhaps a restoration becomes a modification by necessity when you can't find original parts, but at least I intend to not modify it.

Perfectly paired with Beovox 1000's.. How sad I missed an auction on tradera.com yesterday of a white Beomaster 1000, a Beogram 1000 and a pair of Beovox 1000. Went for 675 kronor (approx 70 euro).
Felt like now that I have 3 Beomasters (and Christian is kindly helping me with two of them), I couldn't find a reason to buy another one, not at the moment at least..
But the Beovox 1000's, they're good you say..?

At home now a white Beomaster is paired with Castle Kendal speakers, the original version hand built in England in about 1971. Restored by Andrew in the UK, who I again really recommend! It's the third pair I buy from him.
Power handling 40W they say, larger speakers than the Beovox 1000's, but the match is really good!
Below is a photo of them after restoration and while being restored. Not only cosmetically, but internal wiring and capacitors were replaced, and a new pair of drivers to better match the originals (which had been replaced).
I was afraid these would be too big for the Beomaster but it doesn't seem so. Do you have any experience of non-original pairings with Beomasters?
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I have run nearly all my speakers (Beovox 1600 to M70) with the BM 1000 no problems what so ever, also some non B&O 4,6 or 8 ohms no problems