Making my own powerlink mk2

[Lluís Campaner]

Helloo,

So a few months ago I bought a pair of Penta MK2 with a beomaster 6500 as I was so happy with my first b&o product a beolab 2500, but I’ve been having some trouble and I come to ask if you could help me.

 

I bought some really cheap 8 pin cables and everything works but everytime I change the volume or do anything with the remote I get some kind of interference, as far as I understand it is cause the cables are not shielded.

And now comes the question, as I don’t have a big budget and because I would like to make my own custom length cables is cat6 stp a good cable for this use case? Or should I go for other kind of cable?

I would be really grateful if you could help me as I have not been able to find info on this topic.

 

(On the extra note the transformer on my beomaster is really loud, is this common? Just tightening or adding some cushions could fix it?)

[Madskp]

I think it depends on how the individual cables are shielded.

If you can fin the Beolink Handbook (available for paying members on Beoworld In the Biotech section) you can see the cable drawings with pinouts. For the RJ45 Powerlink cables the wire collars are the same as n a network cable, so I will assume it can be used. I did use I Believe CAT6A network cables to make some short RJ45 to 8 Pin DIN adapters at some point, and they work fine. But might be different for longer cable runs.

Location: Denmark

[Guy]

Lluís Campaner wrote:

(On the extra note the transformer on my beomaster is really loud, is this common? Just tightening or adding some cushions could fix it?)

Danish Soundparts (a Beoworld Sponsor) do sell some new support rubber bushings that may help alleviate the problem:  https://www.dksoundparts.com/product/transformer-bushings-beomaster-3500-4500-5000-5500-6000-6500-7000-etc/

I replaced the bushings on my BC9500; it still hums but to be honest I cannot tell if the humming is reduced!  The old bushings were very brittle, however, so new soft rubber should theoretically improve the damping.  You could also look at re-positioning the Beomaster away from any shelving that may resonate and amplify the hum.

Location: Warwickshire, UK

My B&O Icons:

[TK]

The “Buzz-Buzz”ing you hear during during song and system changes is most likely the Datalink messages being sent by the BM to update the Penta displays.  You’d be able to confirm this if you disconnect the Datalink wires in the terminals and the buzzing stops.

Just strategizing – a potential inexpensive fix is to run data in a separate 2-wire shielded cable alongside the Powerlink cable, and reconnecting them at the two Din-8 fixtures, or by using the separate 4-pin speaker connections to just run data from the BM to the Penta, and keep the Powerlink for just audio sigmal. I have not tried either method, so I can’t speak to how well either method will work, including whether there might be other modifications needed to the Pentas to use method two. Good luck!

Just an afterthought – there is probably a straightforward way to have DL signal broadcast wirelessly around the house from the BM via a DIY contraption – it’s a very low baud rate.  A real Rube Goldberg solution.

[speedsixdave]

Lluís Campaner wrote:

(On the extra note the transformer on my beomaster is really loud, is this common? Just tightening or adding some cushions could fix it?)

I’m on my second Beomaster 6500 now as the first one also had a really noisy transformer. I bought them from the brilliant Mark at https://www.ebay.co.uk/usr/vintageandvinylaudio who happily exchanged the noisy first one for a much quieter replacement.

As Guy says the problems are likely (a) the internal support bushings and (b) the surface it sits on. Ours sits on a lovely Nathan Circles sideboard which acts as a massive resonator for the buzzing and vibration. If I put the BM on carpet you couldn’t really hear the transformer buzzing unless you had your ear next to it, but on the sideboard it was really noticeable.

First thing to try though is some better foam or rubber feet for the Beomaster. A set of pads to stop furniture scratching wooden floors is a good starting point for the cost of pence/cents, this is what I’ve done for the second BM6500 and it’s essentially silent now even on the sideboard. Squash balls cut in half are better but more pricey and more obvious. A foam mat might do the trick and be unobtrusive but I’d want to make sure there’s airflow under the Beomaster. Changing the internal bushings is probably the best answer though if you are confident with the mechanics.

Location: UK

Favourite Product: Beolab 3000

My B&O Icons:

[Author]

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