Marantz PM-70 (circa 1981)
The Marantz PM-70 is a stereo pre-main amplifier from the early 1980s, originally priced at ¥69,800. Documentation is thin. No production years, formal reviews or detailed reception history survive in the archive's sources. What is known comes mostly from period spec listings, and they describe a well-featured integrated amplifier typical of Marantz's early-80s approach.
The big feature on the PM-70 is the front-panel graphic equalizer. Each channel gets its own independent 5-element unit, with center frequencies at 50 Hz, 200 Hz, 800 Hz, 3.2 kHz, and 12.8 kHz, each adjustable by ±10 dB. A Tape EQ switch in the center of the equalizer applies the same tonal correction to the recording source, not just the monitor path. The front panel also carries two headphone jacks with a Normal/High level switch that can double headphone volume to suit different headphone types.
The PM-70 is rated at 80W + 80W into 8 ohms (20 Hz-20 kHz) with total harmonic distortion of 0.015% at rated output. Frequency response is specified at 10 Hz to 70 kHz ±1 dB, with a damping factor of 250. Signal-to-noise is rated at 90 dB for phono MM and 78 dB for phono MC. The MC figure comes from an ultra low-noise, high-gain equalizer that accepts MC cartridges directly, with no external step-up transformer. Marantz called the amplifier's servo design the L (linear) servo circuit. It combines a DC servo and a distortion servo that compare input and output signals, then extract and cancel noise, DC components, and distortion introduced by the output transmission path and speaker back-EMF.
Physical dimensions are 416 mm wide, 117 mm high, and 329 mm deep, with a weight of 8.5 kg. A related variant, the PM-70S, shows up in separate listings as an integrated amplifier with graphic equalizer, but its specifications are not clearly documented. One Portuguese listing for the PM-70S asks €680 in "new condition, all original in packaging," while a used PM-70 appears on a Vietnamese classified site for 1,000,000 đ. A passing photo caption also groups the PM-70 with Marantz TA 70 and ST 70 models, though no formal family relationship is established.
Known Specifications
- Rated output: 80W + 80W (8 Ω, 20 Hz–20 kHz)
- THD at rated output: 0.015%
- Frequency response: 10 Hz–70 kHz ±1 dB
- S/N ratio: Phono MM 90 dB, Phono MC 78 dB
- Damping factor: 250
- Graphic equalizer: 5 bands per channel (50 Hz, 200 Hz, 800 Hz, 3.2 kHz, 12.8 kHz), ±10 dB
- Dimensions: 416 × 117 × 329 mm (W×H×D)
- Weight: 8.5 kg
eBay Listings
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- Marantz 1200 (1972–1975; some sources say 1974–1976)
- Marantz Model-1030
- Marantz Model-1040
- Marantz Model-1122
- Marantz Model-1150mkII
- Eico 3150 (1967)
- Fisher CUSTOM-ELECTRA-I (K-14/K-15) (1957)
- Fisher CUSTOM-ELECTRA IV (E33/E44) (1960)
- Akai AM-2400 (1978)
- Akai AM-2600 (1977)