DENON PMA-590
¥ 59,800 (released in 1990)
Commentary
Pre-main amplifier with optical Class A circuit.
The power amplifier section employs an optical Class A circuit, which amplifies music as pure Class A up to the average level of music, and uses a non-switching Class A method effective in reducing crossover and switching distortion at high output.
A newly developed bias control circuit controls the amplification method depending on the input level. An optical element is used to transmit the control signal from the bias control circuit to the power transistor bias circuit. This eliminates interference between the main signal system and the bias control circuit, and achieves high-speed bias control.
A large power transformer is used in the power supply section, and an electrolytic capacitor of 8,200 μ Fx4 is installed in the block capacitor.
A buffer amplifier is installed in front of the volume control to lower the impedance of the volume control circuit and improve the SN ratio in actual use.
In addition, we have achieved improved decoupling between left and right channels and between functions.
Equipped with a CD Direct connector, the signal from the CD player is sent directly to the power amplifier by simply switching the selector switch, enabling high-purity playback.
It has a processor loop function that can be connected to a graphic equalizer or surround processor.
Equipped with MC/MM switchable equalizer amplifier.
In addition to the conventional bottom chassis, a bi-breath plate with three structures consisting of two steel sheets sandwiched between polymer sheets is added, and another steel sheet is stacked on top of the bi-breath plate to greatly increase the rigidity of the chassis.
In addition, vibration is absorbed by the top cover damper material to achieve non-resonance and high rigidity.
Features include tone control with tone defeat, loudness control, and subsonic filter.
Reset-type high-speed protection circuit is adopted.
Model Rating
| Type | Pre-main amplifier |
| Power Amplifier Unit | |
| Rated Output (20 Hz ~ 20 kHz) | 115W + 115W (6 Ω) 95W + 95W (8 Ω) |
| Input Sensitivity / Impedance | Processor Loop Input : 150mV/15k Ω |
| Total harmonic distortion factor | 0.05% (20 Hz to 20 kHz, 48W, 8 Ω) |
| Dynamic Characteristics / Dynamic Power | 270W (2 Ω) |
| Output bandwidth | 5 Hz to 50 kHz (output 48W, 0.5%, 8 Ω) |
| Line input frequency characteristic | 4 Hz ~ 100 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 : 390 mW (8 Ω), 8 ~ 400 Ω Compatible |
| Preamplifier Section | |
| Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC : 0.25mV/100 Ω CD, Tuner, Aux1, 2 : 150mV/47k Ω CDDirect, Tape1, 2 : 150mV/10k Ω |
| Maximum Output / Rated Output | 10V/150mV |
| Total harmonic distortion factor | 0.003% (Rec out & Processor Loop out, 1 khz, 1 v) |
| RIAA deviation | 20 Hz ~ 50 kHz ± 0.3 dB (MC ~ Rec out & Processor Loop out) |
| <General> | |
| SN ratio (input ratio (input short-circuit, auditory sense compensation A) | Phono MM:82dB Phono MC : 62 dB (at 0.25 mV input) CD, Tuner, Aux1, 2 : 103 dB CDDirect, Tape1, 2 : 106 dB |
| Tone control characteristics | Bass : ± 10 dB (100 Hz) Treble : ± 10 dB (10 kHz) |
| Subsonic filter | 16 Hz, -12dB/oct. |
| Loudness control characteristic | 100Hz:+8dB 10kHz:+7dB |
| Power supply voltage | 100 VAC, 50Hz/60Hz |
| Power consumption | 175W |
| External dimensions (including legs, knobs, terminals) | Width 434x Height 145x Depth 363 mm |
| Weight | 15kg |