I recently serviced a lovely Denon DP-30L direct-drive turntable and decided to spread the word a little about this great deck.
Denon’s DP-30L is an excellent turntable with great features like a quality motor, solid chassis and excellent speed-control circuitry. The DP-30L weighs in at just under 10kg, much more than today’s lightweight decks. This deck also has commendably low wow and flutter. This is in part due to Denon’s use of unique speed control methodology.
Unlike most other manufacturers who use hall sensors or printed circuit traces to generate the speed control signal, Denon chose to print a magnetic strip encoded with a waveform, on the underside of the platter. This strip is read back by a magnetic tape head, very similar to the type you’d find in a cassette deck. As the platter spins, the tape head reads the signal from the strip and feeds it into a comparator. A reference frequency is also fed into the comparator. As its name suggests, the comparator ‘compares’ the two and speed adjustments are made based on the difference between reference and generated frequencies.
Denon utilised this method of speed control in all their direct drive decks from this period, and it works very well. In fact, it’s more reliable than some other methods of sensing rotational speed. Of course, speed control relies on the measured signal being precise. Nothing is perfectly machined or completely flat, so some wow and flutter is inevitably ‘built in’. The result is still usually far better than belt-drive decks.
The DP-30L would make a perfect deck for someone upgrading from a belt-drive deck, perhaps buying their first proper direct-drive. You can expect dramatically improved pitch accuracy, lower rumble and more predictable operation from a quality direct-drive deck like the DP-30L. You’ll also get a nice tonearm and the ability to play with most medium compliance MM and MC cartridges.
Drive system: AC servo motor, direct drive
Wow and flutter: 0.015% WRMS (servo)
Signal to noise ratio: 78dB
Tonearm: S-shaped (mk1), straight low mass (mk2)
Dimensions: 450 x 140 x 403mm