gunnet wrote:

The Quad 306 is a 50wpc solid state power amp from the 1980's to early
90's. It did not use the more common current dumping technology of the
larger 405 or 606 model but is still a very good little power amp none
the less. You should not worry about it driving speakers with 89db
efficiency as this is a very common rating. Used sensibly its ok.
The seller said it was of 1997. Could it be?

No it was discontinued earlier than that as there was a range called 77
came out in about 1994.
Regards,
Borosteve.