beosystem w/ devialet phantom?

[ogs]

That would be possible, but difficult and complex. I do not think the Beomaster 6500 has a pre amp output, only loudspeaker outputs (that control volume, tone etc.) You'd have to somehow run the speaker level outputs through a attenuator device to make it line level, then through an Analog to Digital converter with a Toslink (optical) output connected to a Devialet Dialog for connection to the Phantoms.
Certainly not an ideal way of connecting Phantoms. The sound character of the Beomaster power amp wound be in the signal path and colour the sound. You would have to be careful with the B&O volume control not to overdrive the AD converter (and produce digital clipping) Also tone controls could produce this overdrive.
A different approach is to use the same output that goes to a tape recorder into the AD converter. You could not use the B&O remote for other that switching inputs (no volume, tone, balance, effects) on the Beosystem, but you could still use your Beosystem. You'd then use Spark for volume control.