The CR-820 had a wonderful quiet phono stage. It was the best in that series of receiver and had the same stage in the CR-620. Both remarkable phono stages.
I have an AS-501 and really liked the phono stage in it. Then I got a Parks Audio Budgie just to see what the deal was and I found it to be a big improvement. I have swapped back and forth and it is definitely better. The Yamaha sounded good but this is great. That's how it is to my ears.
Second on the Budgie. In my experience, that's the best in that price range for ready-made. If you can do a DIY kit, the Tavish Design Vintage is another good tube-based phono pre that sounds great.
I've owned several CR-820s, sold them all. Repaired many more. The phono stage ranked as one of the poorest sounding RIAA stages I have ever heard. It's a three transistor design- yes, three. They really pushed the boat out on that didn't they?
Here's the schematic of the left channel, CR-820 RIAA stage:
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