Beogram 7000 and Beosystem 6500

[Giorgione]

Hey forum,

I have a BG7000 that I ran for a couple of years connected with a BM5500 (CD socket), which wasn’t an ideal combination of course, but I had neither a BG5500 nor a BM6500/7000 at that time. Now I finally found a BM6500, connected it to the BG7000’s phono socket, but no data signal seems to arrive from the BM to the BG. The BM does switch to “Phono” when I push the dedicated button on my BL1000, though, but the BG doesn’t respond.

I thought that the BS6500 and the BG7000 were supposed to match, am I wrong?

I also have a MCP6500 which doesn’t seem to recognize the BM6500.

Thanks for your help!

[Guy]

Madskp wrote:

I can’t tell from the service manual if the RIAA in the BM6500 is a separate board that can be  be removed, as it is only shown as part of a diagram where it is surrounded by dashes and market RIAA amplifier acesory, and the text about cutting pin 7 when RIAA is mounted.

It is a separate board that sticks up vertical from the main board just behind the input sockets.  There are pictures of an RIAA board attached to the first couple of posts here: https://archivedforum2.beoworld.org/forums/p/7576/67094.aspx#67094

EDIT:  I only remember because it was discussed in this thread:  https://forum.beoworld.org/forums/topic/difference-between-source-sugnals/page/2/

[Millemissen]

Hi and welcome.

Are you sure that the din connector of the BG has all 7 pins – the additional 2 are needed for the datalink communication.

MM

[Giorgione]

Hi and thanks for the welcome and the quick reply. I used to be a member before but had to open a new account since I probably messed up something transferring to the new page 🙂

I didn’t even check that, since I have two more BG7000/BM7000 combos that work. Do you mean that somebody could have clipped the data pins or replaced the 7 wire cable. Possible, will check this evening. But – why should anybody do that? Maybe for the use with a non-B&O amp?

CC

 

[Madskp]

There might be another explanation.

As far as I can tell Beomaster’s with built in RIAA use pin 6 in the DIN connector for datalink which is also the case for Beograms without RIAA. Beomasters without built in RIAA use pin 7 for datalink and so does the Beograms with Built in RIAA.

I Belive it is a way for the end user not to be able to start a configuration the will not work: Either two RIAA amplifiers or no RIAA amplifiers.

The BM6500 had an option for a built in RIAA amplifier, and the service manual states that pin 7 in the DIN conenctor should be cut if mounted thus making it impossible to control a Beogram with built in RIAA.

CD and tape sockets use pin 7.

A Guess could be that you have a Beomaster 6500 with built in RIAA.

 

[Giorgione]

When I plugged the BG7000 into the phono socket of the BM5500 I could immediately hear that there was something wrong (two RIAA amps) but that wasn’t the case when plugging it into the BM6500, no distortions at all. On the other hand, when I plug it into the CD socket, there’s no sound at all.

However, if I really was so unlucky to get one of these special BM6500; do you think that a skilled B&O service technician is able to build the BM6500 back to its “original” state? I’ve planned to have one of my BM7000 overhauled  anyway…

[Madskp]

Giorgione wrote:

When I plugged the BG7000 into the phono socket of the BM5500 I could immediately hear that there was something wrong (two RIAA amps) but that wasn’t the case when plugging it into the BM6500, no distortions at all. On the other hand, when I plug it into the CD socket, there’s no sound at all.

Have you tried connecting other equipment to that BM6500’s CD socket just to be sure it is actually working?

Also check if all the pins are in the connector as Millemissen suggested.

Giorgione wrote:

However, if I really was so unlucky to get one of these special BM6500; do you think that a skilled B&O service technician is able to build the BM6500 back to its “original” state? I’ve planned to have one of my BM7000 overhauled  anyway…

I can’t tell from the service manual if the RIAA in the BM6500 is a separate board that can be  be removed, as it is only shown as part of a diagram where it is surrounded by dashes and market RIAA amplifier acesory, and the text about cutting pin 7 when RIAA is mounted. Mayby someone who did som work on one of these units can chime in.

 

[Giorgione]

Hey you friendly folks, Millesmissen was right, the two “upper” pins are missing. Clipped out, it seems, I can see the holes left. So I guess it’s only a minor operation.

[Madskp]

Giorgione wrote:

Hey you friendly folks, Millesmissen was right, the two “upper” pins are missing. Clipped out, it seems, I can see the holes left. So I guess it’s only a minor operation.

Great to hear that it might just be the simple solution.

Just a thought, if you connect it again and activate the input on the Beomaster with the remote can you activate the Beogram via its own play button and hear sound?

[Millemissen]

Giorgione wrote:

Hey you friendly folks, Millesmissen was right, the two “upper” pins are missing. Clipped out, it seems, I can see the holes left. So I guess it’s only a minor operation.

You can read a bit about that here:

Datalink pin for remote control communications DIN cable

MM

[Giorgione]

Yes, I can. But no sound when plugged into the CD socket.

[Giorgione]

Now, that’s good to know, thanks again MM! I was wondering why these tiny holes seemed threaded.

[Author]

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