Kenwood KT-7500 (1976–1978)

The KT-7500 was Kenwood's top-of-the-line FM/AM tuner from the mid-1970s. It belonged to the "Super Audio Component" series and was sold alongside the KA-7100 integrated amp. It came out in 1976 at ¥69,500 in Japan and $310 in the US. Kenwood designed it to be the reference tuner of its generation, and by most accounts it earned that role.

The FM section uses a five-gang variable capacitor and a double-balanced front end. The tuning is direct-coupled, and Kenwood claimed this reduced the "swishing" beat distortion thought to be inherent to stereo FM broadcasting. There is a multipath output terminal, an MPX noise canceller circuit, a stereo-only switch and a muting switch. A variable audio output level control is also fitted, handy for matching downstream gear.

FM performance was strong for the era: 1.8µV mono sensitivity (IHF), a 2dB capture ratio, and 70dB selectivity. Frequency response was rated at 30Hz–15kHz ±0.5dB, with 0.3% mono distortion and 0.5% in stereo. Stereo separation was 45dB at 1kHz. Kenwood's own advertising in Audio (February 1978, p.51) touted the KT-7500 as a preview of where FM performance was heading by 1980 — and highlighted that it cost only $275, a notable price point for a tuner of this caliber.

The AM section is more modest, as you'd expect. Sensitivity is 300µV/m, selectivity is 40dB, and signal-to-noise is 50dB. Output is 0.65V on FM and 0.4V on AM. The unit draws 12W, measures 411×109×300mm, and weighs 5.1kg.

The sources disagree on a couple of specs. FM stereo sensitivity shows up as 40µV in some and 30µV in others. The more conservative 40µV figure comes from the manufacturer's own documentation, so it is used here. Mono signal-to-noise is listed as 75dB in manufacturer specs and 70dB on at least one enthusiast site. The 75dB figure is the one Kenwood published.

A successor, the KT-7500 II, appeared later. The original has a strong reputation among collectors, who often describe it as keeping up with tuners costing several times more.