[Nebojsa Jankovic]

Hello Emma, I need to clarify once again! Sorry if I was confusing you. As I had already said on Sep 17th, your best bet is to get the correct DIN-to-RCA cable, then go through your RIAA preamp to your speakers, as they do have an amplifier built-in. This should simply work…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hi Emma, I sympathize with you at this moment, as I imagine you are overwhelmed with responses and suggestions! Nevertheless, your first thing to eliminate is the DIN5/7-to-RCA cable, as  where everything starts (or ends) is literally in the pinout compatibility from the BG5500 DIN5/7 plug to the corresponding female DIN5/7 plug on a DIN-to-RCA cable. So, either Sounds Heavenly (Beogram to non-B&O device phono preamp, amplifier, receiver, with internal ground link) or AV Connection (AV-advance B&O turntable adapter) cable should work, as both are specificaly wired to work with any Beogram turntable. Do note, again, that Sounds Heavenly cable does not come with a separate ground wire next to the two RCA’s, so is pre-wired to make it compatible with any non-B&O device, because not every preamp or amp/receiver comes with a ground terminal to connect to…

• This reply was modified 6 hours, 3 minutes ago by Nebojsa Jankovic.

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Steve sells the SubZero PPA-2 preamp with input gain and monitor level controls.

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

The speaker in your photo seems to be just Kanto YU, basic model, so does not have input type selector…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

I had the same problem with my 4004 earlier this year and fixed it mid-June. See attached photos for reference, specifically the 1st one (I am showing a DIN7 plug, but only pins 2, 3, 5 and shield are required for functionality), while the 2nd one really shows that the system ground and signal ground must be one and the same! This is specific to the Beogram 4004 version only!

Back to your DIN plug coming out of the 4004, need to open it, make sure that the black wire is disconnected (desolder it and tuck away) from the plug housing, than take the shield wire, connected to pin 2, split it in half, and solder part of it to the shield of the plug (in place of the black wire)! This way, system GND and signal GND (L/R low) of BG4004 will be at the same potential, so should become independent on the RIAA types/models and how they have GND implemented internally…

Courtesy of Rudy, aka Beolover, he confirmed this for me as well: 

“It is my experience that connecting shield and system ground usually takes care of humming. In later 4004s they actually implemented this as factory standard on the output board. It only took them ~5 years to figure it out back then…”

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hi Emma, have you tried connecting your turntable directly to the speakers?

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hello Emma, you have an active speaker, so you need additional Line Level Booster connected between your preamp and your speaker, see attached photo for a proven one, from Nobsound (Douk Audio).

Kind regards, Nebojsa

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hello, there is no MMC20 cartridge. Only MMC20S/E/EN/CL, so 4 types, ligned-up low-to-high in their specs, see also this website, withcartridge database!

https://www.vinylengine.com/cartridge_database.php

I am not aware of a “type A” cartridge that B&O had made…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Can anyone confirm if Beocenter 7002 and 7007 have the identical LED display, please? I can get a former with functional  display very cheap and use it as a donor for my BC 7007!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Your photo shows a female input of your BM, which should mate with a male DIN5/7 plug, which should be wired as in the attached photo. Attached photo shows the back of the DIN plug (solder view). If all of this is correct, it does seem that the DIN plug wiring pinout should be reversed as in a mirror image, to match your BM input plug. Also, check on your DIN plug if you have wired also the plug housing…

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hello again, as I feel it is essential for the success and value of our forum, to provide an update on the successfull resolution of my problem on the BC7007! I had reported two issues, primary of the system power-down after 10-30sec and secondary of the issue on the left channel on the Speakers1 output. Both causes had to do with failure mechanism of component wear, logical and expected on a 50-year old system!

Power-down was diagnosed to go back to the surface corrosion on the two potentiometres (adjustable resistors in either left and right amplifier circuit), that provide bias required to be precisely at 1.1V on the emitter of transistor Tr210, see attached photo of this part of the circuit for the left amp (R224 and TR210, circled red and green respectively). After cleaning of corrosion with contact spray onboth potentiometres and fine adjustment back to 1.1V, power-down issue went away permanently!

Speaker output issue was traced miracleously to a short inside the Line-in plug on the rear connections terminal (white/light grey cap), so this was permanently fixed by going a step inward, bypassing the plug jumpers by creating permanent connection on the back board of this circuit located in the back of the in-out terminal. Additionaly, as during this exercise, issue of channel output began moving back-forth between Speakers 1 and 2, this was traced to intermittent function of the speaker 1/2 buttons on the main system control panel, so their respective back contacts had to be also cleaned by contact spray!

I hope this may help our team members, as they experience similar symptoms!

Kind regards!

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

A self-correction is due, as I now see that I mistyped, it should have said “lots of work, easily 100 hours”. All have gone into diagnosing, fixing, modelling, reading circuits, adjusting electrically, physically, testing, retesting, trials and errors…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hello Madskp, I cannot agree more with you! I just posted those to illustrate my point, made and summarized very explicitly earlier! I have also done multiple cross-checks for the online information and have concluded that I can only trust what I see and what I probe. On the image posted by Layesera, I can see clearly white (to pin 3) and red (to pin 5) wires, left and right high signal, yellow for data (to pin 6), but then 3 other wires all seem black, so one of them should go to pin 2 (shield), one to plug housing… And this image is a view from the solder side of the DIN plug, inside of the plug.

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Incredible piece, complicated design, but extremely sensitive! Typically, during its 50 year life, people have worked on it, so have likely changed things, fixed some, created and left hidden problems behind… Components had not been made to last this long, so are now walking wounded issues. It requires extremely precise mechanical/physical alignment between stationary and moving sub-systems, coupled with analog components that deteriorate, so any bit more complex fix and service may work out, but can also screw up its incredible balance by design! All of the boards in my system have by now been resoldered on every point, 60% of components that have naturally aged have been replaced (once a board is out, this is the most prudent thing to do…), every mechanically moving part dissassembled, serviced, cleaned, greased, reassembled, realigned, all tested, functionally and electrically etc. Incidentally, if one is lucky, they can be very happy, as 5 years earlier I had bought a fully working/serviced 4002, and it still works perfectly, without anything touched in it! Hope not to have cursed it for my son, who has taken it over from me!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

I bought a 4004 for €550, with an issue on the tonearm, would not go down on the LP… Since then, I have made it perfect, but has cost me 4x the additional investment, with lots of work, easily 300 hours) and learning, with great help from Rudy, himself and his video blog, plus lots of work from a local HW specialist… It has been a long and difficult process, but fully worth the experience and result, as this is to be expected from a 50 year-old vintage piece of amazing design and engineering! Remember, B&O offer the new limited number release of Beogram 4000C to european customers at €20.000. They are all probably gone… They also now offer refurbishment service for the 4000/02/04 and that won’t cost less than €5000… So, go for it, if you want to keep it for the next 20 years!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

most of the time pin numbers are as in the attached photo, looking at the inside of the DIN plug, the solder side. Also, see some online information specifically for the BG7000 system, BUT in this case, I can’t be sure if the numbers are from the solder side or the face-side of the plug…

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

I asked you earlier what exactly is wrong with your cable, because if the cable itself is not physically damaged anywhere, it is highly likely that your problem is inside the DIN plug, where a wire solder connection has come loose! Therefore, your best bet is to carefully open your DIN plug and check it out visually for any opens on its pins! As Guy also wrote in the meantime, even if you source an open-ended DIN7 cable, you will still need to identify its pin-out between DIN pins and open ends of its core wires, either by using multimeter or opening the DIN plug…

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

here is a typical image of a DIN7 plug, the solder-side of it

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

Hello, yes, pinout is vague, because it requires common sense, rather than blind following! Here is a summary:

– There is no DIN fly lead cable with identically colored wires, as in your BG7000

– Noone can give you this for your system! I tried to look at the RIAA diagram in the BG7000 service manual, but could not conclusively identify its output channels!

– you need to identify, by YOURSELF,  the pin-to-pin connections between the output of your RIAA board (as in your photo, see attached) and the back of your DIN7 plug, that would be what is called “solder side” of the DIN7 plug

– therefore, you need to open your DIN7 plug and see the inside of it, so you know for certain how its pins are connected back to the output of your RIAA

– online diagrams refer to DIN plug pin numbers 1-7, but it is not always clear looking from which side of the plug, the solder side or the outside of the plug, so tobe absolutely sure, you need to do this yourself!

– Once you have identified RIAA-to-DIN pin-to-pin connection, you can take any cable with 7 wires and manufacture your new cable!

kind regards

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Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

[Nebojsa Jankovic]

What Guy suggests is a pre-wired DIN7, so you need to make sure you take the correct pins and solder their wires to the right terminals of the RIAA, badically following the exact pin-out of your DIN7 cable! Alternatively, as the original B&O cable cannot be sourced anymore, you just need to get a generic cable with 6 wires, plus shield and a new DIN7 plug and make your own cable by copying the pin-out from your existing cable. (Not to mention that you actually may not need more than 3 wires, plus shield, if you use your Beogram as a stand-alone turntable.) If you are handy with a multimeter, you can also check what is wrong with your cable and fix it!

Location: Eindhoven, NL
Favourite Product: Beogram 4002/04, Beocenter 7007, Beosound 6000/02

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