DENON PMA-980
¥ 138,000 (around 1986)
Commentary
This is a pre-main amplifier that is suitable for the CD era and has all circuits refined by introducing the design concept of a separate amplifier.
The power amplifier section is equipped with dual super non-feedback circuit.
This circuit consists of a distortion servo circuit in which distortion is mutually cancelled by each transistor of N channel and P channel of the power stage, and does not have an NFB circuit.
This improves signal transmission speed by eliminating the NFB loop and reduces dynamic distortion.
It not only reduces static distortion to 0, but also eliminates distortion even in the high-order harmonic distortion region of ultrahigh-frequency signals because of its excellent distortion elimination capability.
In addition, since there is no NFB loop, the influence of the back electromotive force when the speaker is connected does not reach the voltage amplification stage, thus suppressing the generation of dynamic distortion.
A Pc130W power transistor is used, and a parallel push-pull complimentary service circuit is used.
All signal paths are fully capacitorless (fully DC configuration).
In addition to a 390 va toroidal transformer, the power supply employs a φ 50x100mm block capacitor (12,000 μ Fx4) and fast recovery diode with high-speed rectification.
In addition, the newly developed balanced floating power supply system achieves stability equivalent to that of the left and right independent power supply.
In order to reproduce the CD quality as pure as possible, it is equipped with CD direct input terminal (gold plated finish).
When the direct switch is ON, the CD source is directly connected to the volume, and the signal is connected to the power amplifier without passing through the input selector or Rec Out switch.
On the first stage, a wide-band equalizer amplifier with differential amplification by low-noise FET connected in parallel is mounted.
Equipped with real time tone control with turn-over switching.
Model Rating
| Type | Pre-main amplifier |
| Power Amplifier Unit | |
| Rated Output (20 Hz ~ 20 kHz) | 140W + 140W (8 Ω) 170W + 170W (6 Ω) |
| Input Sensitivity / Impedance | Tuner input : 150mV/47k Ω |
| Total harmonic distortion factor | 0.003% (20 Hz to 20 kHz, 70W, 8 Ω) |
| Cross modulation distortion factor | 0.002% (equivalent to 140W, 8 Ω) |
| Dynamic Power | 440W/2 Ω |
| TIM Distortion | Measurement limit value or less |
| Slew rate | ± 350 V / μ sec or more |
| Output bandwidth | 5 Hz to 80 kHz (70W, 0.02%, 8 Ω) |
| Frequency characteristic | 1 Hz ~ 250 kHz, + 0 -3dB (1W, 8 Ω) |
| Output impedance | 0.1 Ω or less |
| Output terminal | Speaker : AORb : 6 ~ 16 Ω, A + B : 12 ~ 16 Ω Headphone Jack Maximum Output : 550 mW (8 Ω), 8 ~ 400 Ω Compatible |
| Preamplifier Section | |
| Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC (High) : 0.25mV/100 Ω Phono MC (Low) : 0.125mV/100 Ω CD1, 2, CD Direct, Tuner, Tape1, 2 : 150mV/47k Ω |
| Maximum Output / Rated Output | 14.5V/150mV(Rec Out) |
| Total harmonic distortion factor | 0.001% (Rec Out, 1 khz, 8 v) |
| RIAA deviation | 20 Hz ~ 100 kHz ± 0.2 dB (MC / MM IN ~ Rec Out) |
| <General> | |
| SN ratio (input ratio (input short-circuit, auditory sense compensation A) | Phono MM : 90 dB at 2.5 mV input Phono MC : 75 dB at 0.25 mV input Line : 110 dB (at 150 mV input) |
| Tone control characteristics | Bass : ± 8 dB (50Hz/100Hz) Treble : ± 8 dB (10kHz/20kHz) |
| Subsonic filter | 18 Hz, -12dB/oct. |
| Loudness control characteristic | 100Hz:+7dB 10kHz:+6dB |
| Power consumption (Electrical Appliance and Material Control Law) | 245W |
| Pwer | 100 VAC, 50Hz/60Hz |
| External Dimensions (including foot, knob, terminal) | Width 470x Height 167x Depth 446 mm |
| Weight | 16.3kg |