RX- 900U loudness control?

[oskaraleman]

Recently acquired a Yamaha RX-900U Natural Sound Receiver for $20 at the local thrift, + a buck for the copper wire to replace the missing pre/main jumpers and lack of sound output, thanks AK!
Currently running with a Carver SD/A-450 CD player into a pair of Fried A3a loudspeakers.
Can anyone give a brief primer on how to effectively use this loudness control feature?

 

[Electone]

Turn the main volume knob to where you feel would be the maximum level you would listen to, and then from there, use the loudness to control your volume now.

 

[oskaraleman]

Thanks for the response, Electone...guess I was curious 'bout the red numbers going from Flat Loudness at the top to -40db at 2 o'clock as the ring is rotated to the left. Just window dressing or do these reference something? A fill in unit for the now, but I do like the sound and look of this receiver...the flip down panel is cool.
BTW, I've owned a Nova Craft canoe for the past ten years, a Bob Special...nice boat, waiting for the water to liquefy.