I shouldn't have expected any different from the 920 once I started working on it. Especially right after getting the 900 going. I really think it is just the electronic controls for the motors that causes the growl. It isn't unbearable by any means but it certainly is louder than a silky smooth vintage cast iron Singer 15-91.
Hmm, looks strikingly similar to the 900, don't it. This is the free-arm version.
Pretty nifty. Everything else looks pretty much the same between the 900 and 920.
Here's a shot of the white plastic bushing that was cracked on the 900 (see previous blog entry).