DENON PMA-690

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