Kenwood KD-4100 (1977–1979)

The KD-4100 is a direct-drive turntable Kenwood produced from 1977 through 1979. It was a mid-priced deck — Stereo Review (April 1977) tested it at $195 — while sharing their basic engineering approach: a DC servo motor driving an aluminum die-cast platter, paired with a static-balance S-shaped tonearm.

What makes the KD-4100 interesting today is that it offered a proper direct-drive platform with genuinely good measured performance at a relatively accessible price point. The tonearm is a 220 mm static-balance S-shape with a standard ½-inch headshell mount, adjustable stylus force from 0–3 g, and anti-skating compensation. It handled cartridges in the 4–10 g range. The platter is a 30 cm aluminum die-cast unit weighing 1.2 kg.

Stereo Review's lab test measured wow and flutter at 0.045% wrms (weighted) and rumble at −65 dB, which the magazine noted was "about as good as rumble measurements get." The review found no problems with the deck's performance. Kenwood's own published figures were slightly more conservative — 0.06% WRMS wow and flutter and −60 dB (DIN B) rumble — which is typical of the difference between manufacturer specs and independent lab measurements.

One point of ambiguity in the record: whether the KD-4100 supports 78 RPM. Some sources list 33, 45, and 78; others list only 33⅓ and 45. Given that the period review and the more detailed spec tables both omit 78, it seems likely the deck was a two-speed model — but the sources genuinely disagree, so treat the 78 RPM claim with caution.

Drive: direct-drive, DC servo motor
Speeds: 33⅓ and 45 rpm (78 rpm per some sources)
Wow and flutter: 0.06% WRMS (Kenwood spec); 0.045% wrms weighted (Stereo Review measurement)
Rumble: −60 dB DIN B (Kenwood spec); −65 dB (Stereo Review measurement)
Tonearm: static balance, S-shaped, 220 mm effective length
Stylus force range: 0–3 g
Cartridge weight range: 4–10 g
Platter: 30 cm aluminum die-cast, 1.2 kg
Output: phono (RCA)
Dimensions: 460 × 165 × 380 mm (W×H×D); 9.5 kg
Power consumption: 11 W