The AV receiver market continued to expand this week, with new introductions from high-end component brands Marantz and Integra. Marantz unveiled a pair of slimmed down receivers hitting retail shelves this month in its [amazon_textlink asin=’B06XY7F6MJ’ text=’NR1608 ($749 suggested retail) ‘ template=’ProductLink’ store=’hc005-20′ marketplace=’US’…