Denon TU-1000

Surviving documentation on the Denon TU-1000 is thin. What the record shows: it was a Quartz-PLL synthesizer tuner covering both FM and AM bands, built for the North American market with an original AC 120V/60Hz power supply. A period roundup in High Fidelity (April 1979, p.57) noted that the Sansui TU-X1 was an exception to the FM-only rule in high-end tuners, with its AM section featuring a unique array of signal-optimizing controls.

The spec sheet tells most of what is known. The FM section was clearly the focus. Sensitivity is 1.5µV, mono signal-to-noise is 80dB, mono distortion is 0.15%, and capture ratio is 1.2dB. Those are respectable figures for the era. Selectivity is listed at 60dB at ±300kHz, with image and IF rejection at 85dB and 95dB respectively. The AM side is more modest - 20µV sensitivity, 55dB S/N, 0.5% distortion. That is typical of tuners from the period, when AM was often an afterthought. Output level is 2V on FM.

Stereo FM specs are missing. Only mono figures survive, which is unusual for a tuner of this class and suggests the documentation that once existed has been lost. No production years, original price, or market context have surfaced either.

Type: Quartz-PLL Synthesizer Tuner (FM/AM)
Tuning range: FM 87.5–108 MHz; AM 520–1610 kHz
FM sensitivity: 1.5µV (46dB); AM 20µV
FM S/N: 80dB mono; AM 55dB
FM distortion: 0.15% mono; AM 0.5%
FM selectivity: 60dB at ±300kHz
Capture ratio: 1.2dB
FM frequency response: 30–15,000Hz ±1.0dB
Dimensions: 434 × 111 × 335mm; 6.8kg

If you own one and can fill in the stereo specs, production dates, or any circuit details, the archive would welcome the correction.