Beocenter speaker relais question

My Beocenter 9000, as well as my 9500, are both having sound problems when using them with Beolab Penta Mk1 speakers, connected by SpeakerLink cables. Initially there is almost no sound, until I increase volume to about 50% or higher, then the sound suddenly kicks in. I did not have this problem when I used the Beocenters with Penta Mk2 speakers connected by Powerlink.

I suspect the speaker relais in both Beocenters are oxidised and need to be replaced.

What type of relais is required? Are there any specifications I should keep in mind when searching for and ordering new relais units? Thanks for any recommendation.

I bought an official B&O one from here: http://www.avaservices.co.uk/ and fitted it myself

but I am sure you can find equivalents (or better) elsewhere.

Good idea... Have contacted both your suggested address as well as potential local sources.

Thank you!