Hello all,

Tim Jarman says about the 5500 and its siblings in his Workshop notes that "you will have probably noticed that thesse models give a slightly disappointing sound when used with passive loudspeakers when compared to some of the earlier designs".

Then, "The only substantial difference between the Beomaster 5000 circuit and that used in the later models is the addition of four 220nF capacitors C215, C216, C415 and C416. They are not shown on all the Beomaster 5500 circuit diagrams but many sets have them. As these do not appear in any other versions of the circuit it seemed safe to remove them and see if the performance improved. With the capacitors in circuit the sound from one Beomaster 5500 was lifeless, bland and uninteresting, without them it was more similar to a 5000, engaging and lively with a full, rich tone".

These caps can even go bad. Tim says, "This receiver would switch itself off a second or so after being switched on. The usual cause of this is an excessive DC potential at the loudspeaker outputs so and further tests must be made with the loudspeakers disconnected. In this case -37V was found at the midpoint of the two right hand channel output transistors, normally the voltage should be zero, give or take a millivolt or two. In all B&O amplifiers that use a BF423 transistor this is the first thing to check and sure enough TR205 showed considerable leakage when tested with a meter. A replacement failed to cure the fault however. TR206 (BC547B) read strangely in circuit so this was replaced too but this also made no difference. The true culprit was C215 (220nF / 63V film type) which was leaky. This capacitor is not shown on all issues of the circuit diagram, making tracking down the fault more difficult than it could have been".

So my query is simple: have you experienced this, and what are those caps there for?

Thanks!

chartz:

So my query is simple: have you experienced this, and what are those caps there for?

To create a fight!

http://forum.beoworld.org/forums/t/25939.aspx

EDIT : fixed the link.

Oops I had missed that one!

Thanks for the pointer.

Case dismissed!

tournedos:

chartz:

So my query is simple: have you experienced this, and what are those caps there for?

To create a fight!

http://forum.beoworld.org/forums/t/25939.aspx

Mika:

That was the best thread EVAR!

Any more all time great threads someone who joined last year may have missed?

Rich:

Any more all time great threads someone who joined last year may have missed?

Check Die Bogener, he made some interesting threads about upgrading or rebuilding amps/preamps

Hi,

I have been comparing my newly acquired Beomaster 5500 to my 8000 and it sounds much duller, a bit uninteresting exactly as Tim Jarman describes it.

The tuner section is also less sensitive!

Any thoughts please?

Hello!

Like many of you, I now have a complete Beosystem. I am proud to show it to you, standing on a custom stand.

That's what I paid: Beogram CD5500: €50, non working, had a bad cap and zener. A bargain then! Beogram 5005, again €50, broken MMC4, but mint-ish. Beocord 5000, £50, supplied with new belts, new pinch roller fitted. Finally, Beomaster 5500 plus Master Control Panel 5500, working, £170.

This would have set me back an amazing £3,000 back in the late 80's! I use MC120-2 speakers.

Thanks everybody for your good advice!

I now have two things to fix: the MMC4, and that horrible bunch of wires that I want to disappear!

Ideally, I also should find an IR sensor because of the side wall placement of the stack.

 

 

Hi!

Today, because of a humming transformer, I decided to open my Beomaster 5500. I wanted to re-set the brightness of the display, and here's what I found: 

Not nice eh... Anyway, since it was in the IR sensor region (C20, 10µF 63V, voltage supply), and since I had sensitivity problems... Contact is much better now, even considering the odd angle between the MCP and the system.

I also wiped the IR LEDs clean.

I also replaced the rubber bushes at the transformer. It is still audible, but much, much less so! The rubber grommets were dry and the transformer was in fact free to move!

chartz:

Not nice eh... Anyway, since it was in the IR sensor region (C20, 10µF 63V, voltage supply), and since I had sensitivity problems... Contact is much better now, even considering the odd angle between the MCP and the system.

Didn't I tell you

Do the rest (a couple inside the CPU module and the small caps in the power supply) as well if it gets worse again.

I knew someone did, but I didn't remember who... Thanks then!

I'm about to order new caps for the whole receiver. I can't find any 10µF Wimas though. Some bloke has them on the US eBay but he wants to charge thirteen dollars for shipping!

I finally refused to do anything about those 220nF caps. If Martin says there's a risk it's good enough for me not to do it.

 

Wima here

Yes, we have Mouser here too, but this is the 15mm one. I was talking about the 63V 5mm ones (they will go where radial electrolytics were).