Marantz Model 170 DC Power Amplifier – 86 WPC – Blue VU Meters

Marantz Model 170 DC Stereo Power Amplifier – Made in Japan

Marantz Model 170 DC Stereo Power Amplifier – 86 WPC with Pure DC Coupling and Blue VU Meters

The Marantz Model 170 DC represents Marantz’s golden age of power amplifier design from 1978, delivering 86 watts per channel into 8 ohms with the kind of sonic refinement and build quality that defined the company’s reputation during its peak years. The “DC” designation refers to the amplifier’s pure DC coupling topology—a pure, direct signal path from the RCA inputs to the output transistors without capacitors in the signal chain. This design philosophy, favored by audio engineers in the late 1970s and early 1980s, theoretically delivers a more pure waveform with minimal phase shift and frequency distortion, resulting in a sonic character many describe as “tube-like”—warm, full-bodied, and musical despite being solid-state.

The engineering excellence of the 170 DC centers on its discrete transistor output stage utilizing 53 transistors, 49 diodes, and 4 field-effect transistors in a carefully balanced design that prioritizes low distortion (0.03% at rated power) and exceptional damping factor of 60. This high damping factor provides tight control over speaker drivers, ensuring clean transient response and minimal overshoot in the bass frequencies—a key component of the 170 DC’s reputation for delivering “musical” rather than “clinical” amplification. The power supply employs heavy transformer technology from Marantz’s own manufacturing, providing substantial power reserves and the ability to deliver peak power into 4-ohm loads (108 watts) or 2-ohm loads (170 watts) when necessary.

A distinctive feature of the 170 DC is its iconic pair of large blue VU meters that illuminate beautifully when powered, showing real-time output levels on each channel. These meters serve both functional and aesthetic purposes—they allow you to visually confirm balanced channel operation and provide that classic retro-hifi aesthetic that makes vintage Marantz separates instantly recognizable. The amplifier operates with DC or AC coupling selectable via rear-panel switch, allowing flexibility in signal conditioning based on preamp output characteristics. The design was intended to be powered from the switched outlet of a matching Marantz preamp (such as the legendary 3250B), though it can accept an optional separate power switch retrofit.

Features and Capabilities:

Pure DC coupling signal path (no coupling capacitors in audio signal chain)

Discrete transistor output stage (53 transistors, 49 diodes, 4 FETs)

Exceptional damping factor of 60 for tight bass control

Dual illuminated blue VU meters for visual output monitoring

DC or AC coupling selection via rear panel switch

RCA inputs only (designed to pair with Marantz preamps)

Gold-plated RCA connectors

Discrete power supply with heavy transformer

Made in Japan during Marantz’s golden era

Damping factor: 60

Technical Specifications:

Power Output: 86 watts per channel into 8Ω (stereo)

Power at 4Ω: 108 watts per channel

Power at 2Ω: 170 watts per channel

Frequency Response: 20Hz to 20kHz

Total Harmonic Distortion: 0.03%

Damping Factor: 60

Input Sensitivity: 1.5V

Semiconductor Count: 53 transistors, 49 diodes, 4 field-effect transistors

Input Options: DC or AC coupling (selectable)

Dimensions: 416 x 146 x 302 mm (16.4 x 5.75 x 11.9 inches)
Weight: 14.1 kg (31 lbs)

Cosmetically, this amplifier presents in very good condition with the classic Marantz black faceplate and silver chassis showing normal patina consistent with careful use over decades. The blue VU meters illuminate brightly and beautifully, all controls operate smoothly, and the RCA inputs are clean. The power transformer hums normally with no abnormal vibration. Functionally, this 170 DC has been thoroughly tested and performs beautifully—balanced output across both channels with no distortion or noise, excellent frequency response, and the warm, musical character that made the 170 DC legendary among Marantz enthusiasts.

The Marantz Model 170 DC represents one of the most affordable entry points into Marantz separates ownership, delivering authentic 1970s-era power amplifier design with genuine engineering sophistication. Prized by music lovers and home theater purists for its muscular yet refined sound character, the 170 DC remains a powerful and dynamic amplifier nearly 50 years after its introduction. Designed to pair with preamps like the 3250B or 3300 for the ultimate vintage Marantz separates experience, this unit stands alone as a capable power amp for any quality preamp source.

Purchase with Confidence:

Includes Radique Audio “Bumper to Bumper” Warranty

Perpetual Trade-Back Policy—upgrade or swap with peace of mind

Made in Japan during Marantz’s golden era of power amplifier design; asking $1495