Launched in 1978-79, the Denon PMA-850 is widely regarded as one of the best amplifiers of its time — and certainly among the finest ever produced by Denon. A true reference-class integrated amplifier from the golden era of Japanese hi-fi.
Delivering a solid 85 watts per channel into 8 ohms, the PMA-850 combines precision engineering, robust construction, and musical finesse. It weighs in at a substantial 18 kg, a testament to its uncompromising build quality, with high-grade internal components and discrete circuitry throughout.
One of its standout features is the exceptional Phono section, featuring two MM inputs and one MC input, making it an ideal choice for vinyl lovers and audiophiles with multiple turntables or cartridge types.
The power amplifier section is highly capable, delivering clean, effortless power even to demanding or low-efficiency speakers, thanks to a high-current power supply and meticulous circuit topology.
The front panel features a wide range of controls, including tone adjustments, high and low filters, source direct switch for pure signal path, and a quality headphone output. On the back, there is a generous array of inputs: Phono 1, 2 (MM) and 3 (MC), Tuner, Aux, Tape 1 & 2, and Pre-out/Main-in jacks, allowing flexibility in system configuration.
Technically, the PMA-850 achieved remarkable performance specs for its era, with extremely low Total Harmonic Distortion (THD) and excellent signal-to-noise ratio, rivaling or surpassing many modern amplifiers.
Its sound is dynamic and detailed, yet smooth and refined — capable of rendering subtle textures and transient detail with musicality and authority. It’s an amplifier that invites long listening sessions without fatigue, delivering warmth, depth, and realism across genres.
This is one of those rare vintage pieces that makes you reconsider what real hi-fi performance means, and why some of the best audio gear ever made came from this era. A true classic, both sonically and aesthetically.
Type Pre-main amplifier
Power Amplifier Unit
Circuit system All-stage pure complimentary service push-pull circuit
Rated Output (Both channel drive) 85W + 85W (8 ohm, 20 hz ~ 20 khz, THD 0.01%)
110W + 110W (4 ω, 1 khz, THD 0.05%)
Total harmonic distortion factor 0.01% or less
Cross modulation distortion factor
(60Hz:7kHz=4:1) 0.02% or Less (at Rated Output Equivalent Amplitude Output)
0.01% or Less (Sine Wave 1W Equivalent Amplitude Output)
Output bandwidth 5 Hz ~ 100 kHz (IHF, THD 0.1%)
Transmission Characteristics (at 1W output) DC ~ 100 kHz + 0 -1dB
Input Sensitivity / Impedance 1V/50k Ω
Output impedance 0.16 Ω or less
Signal-to-noise ratio 122dB
Output terminal Speaker AORb : 4 Ω ~ 16 Ω
Speaker A + B : 8 Ω ~ 16 Ω
Headphone port
Preamplifier Section
Output Level / Impedance Pre out : 1 V (Rated), 20 V (Maximum Output at 50k Ω Load)
Rec out : 320 mv (Rated), 20 v (Maximum Output, Load 50k Ω, THD 0.01%)
Total harmonic distortion factor 0.03% (at 3 V output)
Input Sensitivity / Impedance Phono1, 2 mm : 2.5mV/50k Ω
Phono3 mc : 0.37 mV (at cartridge impedance 40 Ω)
Tuner, Aux, Tape : 320mv/40k Ω
Maximum Allowable Input (1 kHz) MM:200mV
MC : 30 mv (40 Ω)
RIAA deviation 20 Hz to 20 kHz ± 0.2 dB or less
Signal-to-noise ratio (IHF, A-network) Phono MM : 89 dB or more (at input short-circuit)
Phono MC : 74 dB or more (at input terminal 40 Ω)
Tuner, Aux, Tape : 100 dB or more (when the input is short-circuited)
Frequency Response (Aux → Pre out) 5 Hz ~ 100 kHz + 0 -1dB at Tone Defeat
Tone Control Variable Range Bass : ± 8 dB (100 Hz)
Treble : ± 8 dB (10 kHz)
Filter characteristic Subsonic filter : 20 Hz, 12dB/oct.
High cut filter : 9 kHz, 12dB/oct.
Loudness control Low frequency : + 7 dB (100 Hz)
High frequency : + 6 dB (10 kHz)
Muting -20dB
<General>
Power outlet Switched : 1 system, 100W
Unswitched-2, 250W (total)
Power 220 VAC, 50Hz/60Hz
Power consumption 215W (Electrical Appliance and Material Control Law)
External dimensions Width 434x Height 164x Depth 400 mm (including leg, knob, terminal)
Weight 17kg