DENON PMA-690
¥ 66,000 (released in 1992)
Commentary
This pre-main amplifier is equipped with a toroidal transformer and New Super Optical ClassA circuit for higher sound quality.
DENON's proprietary NEW super optical ClassA circuit is incorporated into the power amplifier.
The newly developed bias control circuit operates as pure A-class amplification up to general listening power level, and realizes sound quality unique to A-class. Also, optical elements are used to transmit control signals from the bias control circuit to the bias circuit, and interference between the main signal system and the bias control circuit is completely eliminated.
By using a toroidal transformer and a large electrolytic capacitor in the power supply section, instantaneous response power is enhanced.
It uses chassis construction with emphasis on sound quality in which left and right signal paths are minimized and separated independently.
In the PMA 690, the power amplifier section and the preamplifier section are symmetrically separated into right and left, respectively, to completely prevent the magnetic flux of the power supply lock from jumping into other blocks.
In order to eliminate functional circuits unnecessary for sound as much as possible, the signal path from the input terminal to the speaker terminal is minimized, so that switches and volumes are arranged properly and the distance is greatly reduced.
Low-impedance volume control is used to improve the S/N ratio at the listening level.
The Rec out Selector allows you to record a source independent of the speaker output.
Source Direct is installed. When on, control circuits such as Bass/Treble/Balance/Loudness/Sub sonic are bypassed.
Equipped with a Phono Selector that can be used with any MM/MC cartridge.
Model Rating
Type | Pre-main amplifier |
Power Amplifier Unit | |
Rated Output (20 Hz ~ 20 kHz) | 130W + 130W (6 Ω) 105W + 105W (8 Ω) |
Dynamic Characteristics / Dynamic Power | 350W (2 Ω) 270W (4 Ω) |
Total harmonic distortion factor | 0.004% (1 kHz, 52.5W, 8 Ω) |
Output bandwidth | 5 Hz to 50 kHz (output 52.5W, 8 Ω, 0.03%) |
Line input frequency characteristic | 4 Hz ~ 150 kHz + 0 -3dB (output 1W, 8 Ω) |
Speaker output terminal | AORb : 6 Ω ~ 16 Ω A + B : 12 Ω ~ 16 Ω |
Maximum headphone output | 33 mw (8 Ω) |
Preamplifier Section | |
Input Sensitivity / Impedance | Phono MM : 2.5mV/47k Ω Phono MC : 0.2mV/100 Ω Tape1, 2, CD, Tuner, Aux : 150mV/47k Ω (when source direct off) Tape1, 2, CD, Tuner, Aux : 150mV/10k Ω (when source direct is on) |
Maximum Output / Rated Output | 10V/150mV |
Total harmonic distortion factor | 0.001% (1 kHz, 1 V) |
RIAA deviation | 20 Hz to 20 kHz ± 0.3 dB |
<General> | |
Signal-to-noise ratio (Audibility Correction A, Input Short Circuit) |
Phono MM : 94 dB (at 5 mV input) Phono MC : 75 dB (at 0.5 mV input) Line input : 110 dB (when source direct is on) |
Tone control characteristics | Bass : ± 8 dB (100 Hz) Treble : ± 8 dB (10 kHz) |
Loudness control | 100Hz:+7dB 10kHz:+6dB |
Subsonic filter | 16 Hz, -12dB/oct. |
Power supply voltage | 100 VAC, 50Hz/60Hz |
Power consumption | 180W |
External dimensions | Width 434x Height 160x Depth 398 mm (including leg, knob, terminal) |
Weight | 12.4kg |