Marantz 7 (1958–1963)

Name: Marantz 7
Brand: Marantz

The Marantz Model 7 is one of the most celebrated vacuum tube stereo preamplifiers ever built. Introduced in 1958 at $199 (later listings show $225 as the price drifted upward over the production run), it was designed by Saul Marantz to be the finest preamplifier possible, not merely the most expensive. It succeeded on both counts. The Model 7 was an evolution of the earlier mono Model 1, adapted for stereo. It was intended to pair with the Model 2 monophonic amplifiers or, later, the Model 8 stereo amplifier, though it will happily drive any power amp.

The circuit is all-tube, built around 12AX7s. The phono stage offers two gain settings - 2mV high / 4mV low - with RIAA equalization held to ±0.7 dB. Frequency response is rated at 20 Hz - 20 kHz ±0.25 dB, and distortion on line out is a claimed 0.15%. Signal-to-noise is 80 dB on high-level inputs and 60 dB on phono high via line out. There are six inputs total (two phono, mic, tape, tuner, aux) and two recorder outputs, with a maximum output level of 10V. It draws 21W and weighs 16.5 lbs, measuring 15-3/8" W x 5-3/4" H x 9-7/8" D.

The Model 7 was one of the first preamps to handle tape-head input directly, and its phono stage was exceptionally quiet for the late 1950s. The design was widely copied, and it remains one of the most sought-after vintage preamps on the market today. As Audio (May 1997, p.49) noted in a retrospective advertisement feature, the Model 7's reputation had endured for nearly four decades at that point.

The Model 7C was a later version with upgraded features, and the transistor Model 7T followed in 1967 as its solid-state successor. Current market prices commonly show $1,500 - $3,000 depending on condition and provenance, though this has not been validated in sourcing.

What isn't well documented: detailed component-level maintenance guidance (capacitor replacement schedules, tube rolling recommendations), the exact RC network used in the tone controls, and any common failure modes specific to this model. The record is thin on those practical matters, but the Model 7's place in audio history is secure.

Tube complement: 1× 12AX7 per channel
Phono sensitivity: 2mV high / 4mV low
RIAA accuracy: ±0.7 dB
Frequency response: 20 Hz – 20 kHz ±0.25 dB
Dimensions: 15-3/8" W x 5-3/4" H x 9-7/8" D
Weight: 16.5 lbs