BeoLab 3500: how to use the DIN connector as AUX IN

23 replies

KolfMAKER

Bronze

569 posts

Posted January 3, 2024 at 01:00 GMT ? Edited May 5, 2024 at 19:18 GMT

I have a BeoLab 3500 with serial 17xx xxxx, type 1601. I would like to use the DIN connection as an AUX Input. I have tried the following PIN connections (for the pin-numbers I refer to the Peter Pan picture below, so seen from the solder side of a male plug that goes into the BeoLab 3500):

2 = GND, 3 and 5 for Left and Right channel IN.
2 = GN D, 2 and 4 for Left and Right channel IN.

For selecting the DIN in the BeoLab menu I used:

'Menu > Menu > 0 > 4 > Go'. This shows 'MCL SEL' in the display, but only gave a lot of HUM no sound coming through.
'Menu > Menu > 0 > 3 > Go'. This shows 'ML ON' in the display, a slight hum, no sound coming through.

My questions

What is the right Menu operation to activate the DIN connector for AUX IN use?
What is the right DIN-pin use to get the audio signal in?

Location: The Netherlands

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Madskp

Gold

1759 posts

Posted January 3, 2024 at 14:30 GMT

#706546

You have an MK1 which has a different pinout. Have a look at little down in this thread that has the pinout for both the MK1 and MK2

Location: Denmark

KolfMAKER

Bronze

569 posts

Posted January 3, 2024 at 18:08 GMT

#706560

Thnx Madskp! You were right. I made a new Mini-Jack to DIN cable with the pin configuration for MK1 and it worked, when connecting a battery run iPod to the BeoLab. Then I connected a streamer box via the same Mini-Jack to DIN cable, and that caused Hum on the left channel. Any idea what to do about that?

Location: The Netherlands

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Madskp

Gold

1759 posts

Posted January 3, 2024 at 18:25 GMT

#706561

Do you run 2 separate ground wires from the minijack to the Din connector? Then maybe that could be the issue. On my testing cables I have connected pin 3, 5 and 7 (ground for MCL data) with a solder blob and just running one common ground

Location: Denmark

KolfMAKER

Bronze

569 posts

Posted January 3, 2024 at 19:27 GMT

#706564

The cable just has 1 GND wire. The PIN connections I have now look like this:

1 = Left (grey line)
2 = Right (red line)
5-3 = GND (black line)

Question

So, do you mean I should also connect pin 7 with 3 and 5?
And that it should solve the Hum I am having now?

Location: The Netherlands

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Madskp

Gold

1759 posts

Posted January 3, 2024 at 20:01 GMT

#706567

you could try to connect to pin 7 also. When the BL3500 is used in an MCL system all three are connected via the cabeling. Also pin 7 is the only one with direct connection to ground in the speaker

Location: Denmark

KolfMAKER

Bronze

569 posts

Posted January 6, 2024 at 12:38 GMT

#706645

Thnx Madskp. I have ordered a 7-Pin DIN plug, to include pin-7 in the grounding. Will come back with feedback when I have received and tested this.

Location: The Netherlands

My B&O Icons:

Madskp

Gold

1759 posts

Posted January 6, 2024 at 13:07 GMT

#706647

Location: Denmark

KolfMAKER

Bronze

569 posts

Posted January 9, 2024 at 12:36 GMT ? Edited January 9, 2024 at 12:36 GMT

#706744

Here's an update. Today I received the 7-pin DIN plug, so I have just soldered a new cable based on your advice. The pin connections now look like this: Result:

Unfortunately there is no change, I still have the Hum on the Left channel.

In this case an iPod is connection via the Mini-Jack > DIN cable.

When the iPod is powered by an USB wall plug, the Hum is there.
When the iPod is powered by its internal;l battery, the Hum is not there.

Question: What other pin connections can I try to solve the Hum?

Location: The Netherlands

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Ravsted

Bronze

458 posts

Posted January 9, 2024 at 14:58 GMT

#706753

Are speaker and iPod charger in same power outlet ? Try that ! Try different charger. In my case I reduced 'hum' by changing charger to an iPad charger.

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