S.D.B (Super Dynamic Bass), Source Direct function, and 40-station FM/AM preset memory.
Pages 2–3 of the original manual contain safety instructions. While often ignored, this is the true “top” priority for any vintage electronics user. Key points from the UDM3 manual: denon udm3 manual user manual top
First, a helpful note for your search: the most common and effective keyword to use is (with the hyphen). This returns much more accurate results than searching for the combined "UDM3". The official model for these products is usually the "Stereo CD Receiver" . S.D.B (Super Dynamic Bass)