"Cartrivision1" wrote in message
oups.com...
Hi, I have a Bang & Olufsen Beocenter 7700 system. It is an "all in
one" center with turntable, FM tuner, and tape deck. It is rated at
40w x 2. It has hookups for 2 sets of speakers.

I bought this thing called a Quatravox Synthesizer, which is some kind
of 70's surround sound/quadraphonic processor. It is supposed to turn
a 2 channel system into a 4 channel. I hooked it up to my system to 2
sets of bookshelf speakers, one set is a Baby Advent II, and the other
set came from a Mitsubishi bookshelf system. The latter set handles 80
watts. When I turn my stereo up past around 36 for a length of time
(it goes to 60 I think) the receiver will power itself down.

I remember hearing about amplifier clipping and I am wondering if this
is what is going on? That the receiver is not putting out enough power
to drive the speakers. The Beocenter does have a set of what looks
like RCA plugs on the back labeled "Preamp Left/Right Out".

Preamp outputs are just what it says... preamp outputs...
the signal before it goes through the power amp.

I am not
sure exactly what these do. Can anybody shed any light on my
situation?

I have no idea what Quatravox does... but I'm quessing the
Beocenter is shutting down for its own protection.
Are both sets of speakers at least nominally 8 ohms?
You might be presenting to low an impedance to the amp.
Try hooking one set of speakers straight to the B&O
and see if it still shuts down. Then the other.
Then both. If it only shuts down with both...its most likely
because one pair or the other or both are less than 8 ohms.
I'd yank the Quatra thing anyway and see how stereo
sounds.

ScottW