A few months back a very similar thread was started here by a poster with PSB speakers and a Musical Fidelity integrated. Going by memory alone, I believe he posted under the moniker "fishing716". Over 500 responses came in. See if you can dig it up in the archives. Tony (his name), are you out there?
Incidentally, the sanest response he got IMO came from an audio dealer in the NJ area who had dealt with a similar problem for a client and determined that there was a connection arcing over in the system owner's service panel which they discovered by darkening the room where the panel was and observing the periodic flashes as they occurred in the panel.
Again, going by memeory, it seems that fishing716 finally determined that the speaker wires were hooked up icorrectly but that never satisfied me because his system (like yours) would play fine for an hour or so and then suddenly go lifeless.
Incidentally, the sanest response he got IMO came from an audio dealer in the NJ area who had dealt with a similar problem for a client and determined that there was a connection arcing over in the system owner's service panel which they discovered by darkening the room where the panel was and observing the periodic flashes as they occurred in the panel.
Again, going by memeory, it seems that fishing716 finally determined that the speaker wires were hooked up icorrectly but that never satisfied me because his system (like yours) would play fine for an hour or so and then suddenly go lifeless.