The Sony does not have a power amp in, so you would need to connect the cube into the tape monitor loop. There should be a way the optical input would run through the tape loop ( possible ). Because the source is tv only, it is possible that all of the "voice" info is being broadcast in "multi channel" mode, making an assumption that there is a center channel being used. The voice is lowered quite a bit from the mains, and directed towards the center. I do not believe the Kefs are in need of service, if, they have been stored properly ( room temperature and such ), and not under or over driven by an amplifier. Just my thoughts, but I may be wrong.
KEF 107 and Kube setup
I ran into some problems helping my parents connect their new TV to their old unused home theater system. The KEF 107's fill the room very well but vocals from both music and movies sound muffled.
I also found the corresponding Kube which they never used but I'm having trouble getting it to work. The only audio source is the TV connected to a Sony V555ES via digital optical audio. Connecting the Kube to the Pre Out (Front) nor the tape in/outs work. There doesn't seem to be a tape monitor button or a pre amp in so I can't figure out how to get the signal into the Kube and then back to the receiver. Thanks!
Here's a link to the receiver's manual for reference:https://docs.sony.com/release//STRV555ES.PDF
I also found the corresponding Kube which they never used but I'm having trouble getting it to work. The only audio source is the TV connected to a Sony V555ES via digital optical audio. Connecting the Kube to the Pre Out (Front) nor the tape in/outs work. There doesn't seem to be a tape monitor button or a pre amp in so I can't figure out how to get the signal into the Kube and then back to the receiver. Thanks!
Here's a link to the receiver's manual for reference:https://docs.sony.com/release//STRV555ES.PDF