DENON PMA-700mkIII

Commentary

As the third generation of the 700 series, this pre-main amplifier has improved physical characteristics and sound quality.

The equalizer amplifier is made of carefully selected low-noise transistors and high-precision parts, and consists of emitter-follower outputs. The RIAA deviation is kept within ± 0.2 dB by equalizing feedback from the last stage of the emitter-follower, which is not easily affected by subsequent circuits.

The Phono2 input is equipped with a newly designed low-noise head amplifier for the MC cartridge and is a dedicated input for the MC cartridge.
This head amplifier adopts a class A push-pull parallel connection configuration using four PNP and four NPN transistors each, improving the SN ratio when using MC cartridge.
To handle very small input levels, it is directly connected to a dedicated head amplifier. In addition, the dedicated terminal is plated with bacteria to reduce contact resistance.

An emitter-follower circuit is used for the Tape rec output circuit to avoid the effect of tape deck connections on sound quality.

The control amplifier section uses a direct coupling method.
The tone amplifier uses an emitter follower for the first stage, a low-noise FET for the second stage, and DENON's unique tone control NFB circuit, which is fed back from the amplified output of the third stage collector to the second stage, provides low-waviness control characteristics.
An 11-contact rotary switch is used for adjusting the bass and treble, enabling accurate 2 db step switching.
The turnover frequency can be switched between two levels of high and low, or in the case of DEFEAT, the tone amplifier is disconnected and the first stage emitter-follower output is directly input to the next filter switch.

Equipped with a low filter and a high filter. Both filters use 18dB/oct. Butterworth type.

The power amplifier section is DC configuration.
Class A Darlington pure complimentary service push-pull OCL circuit is adopted for the output stage. Class A push-pull configuration of PNP and NPN is adopted from the first stage to the drive stage of the main in terminal. The power supply is separated from the output stage. This class A push-pull configuration improves the stability against temperature changes and power supply fluctuations in the entire power amplifier configuration. In addition, by providing stable bare characteristics with a high gain of approximately 90 dB, a stable NFB of approximately 62 dB is made possible. Low distortion reproduction from low output to rated output is achieved.
In addition, the combination of PNP and NPN cancels the distortion by the push-pull configuration of all stages, and linearity is obtained over a wide dynamic range.

The output protection circuit uses an electronic control circuit so that the sound is not cut even when an excessive input is input. In the unlikely event that a DC voltage appears at the speaker terminal, the relay operates to disconnect the speaker.
The muting circuit at the time of power-on has also been improved so that no noise is generated even when it is turned off by an external switch such as a timer.

In the internal structure, the voltage amplification part (front stage part and middle stage part) for handling small signal is contained in the shield case to prevent the effect of induction noise.

The power transformer uses a cut core with less leakage flux and is sealed in a case.

Equipped with a null balance switch that can be used for balance check, etc.

Mode switch, speaker switch, dubbing switch, monitor switch, etc. are mounted.

Equipped with a loudness control.

Pre-out and main in terminals are mounted.

Model Rating

Type	Pre-main amplifier
Power Amplifier Unit
Circuit system	Pure complimentary service for all stages, push-pull type
Dynamic Output (IHF)	300W (150W + 150W) (4 Ω) 200W (100W + 100W) (8 Ω)
Rated output (Both channel drive, sine wave continuous output)	85W + 85W (4 Ω, THD0.05%, 20 hz to 20 khz) 70W + 70W (8 ohm, THD002%, 20 hz to 20 khz)
Total harmonic distortion factor	0.01% or Less (Sine Wave Rated Output, 20 Hz ~ 20 kHz, 8 Ω)
Intermodulation distortion factor (60Hz/7kHz = 1/4)	0.05% or Less (at Rated Output Equivalent Amplitude Output) 0.01% or Less (Sine Wave 1W Equivalent Amplitude Output)
Output bandwidth	5 Hz ~ 50 kHz (THD0.05%)
Frequency characteristic	DC ~ 100 kHz + 0 -1dB at 0.5W Output
Input Sensitivity / Impedance	1Vrms/50k Ω
Output impedance	0.16 Ω or less
Signal-to-noise ratio	115 dB or more (IHF-A)
Output terminal	Speaker A & B : 4 Ω ~ 16 Ω Speaker A + B : 8 Ω ~ 16 Ω Headphones : Stereo headphone compatible
Preamplifier Section
Input Sensitivity / Impedance	Phono MM-1, 2 : 3.2mVrms/50k Ω Phono MC-2 : 0.32 mVrms (at 40 Ω of cartridge impedance) Tuner, Aux1, 2, Tape PB1, 2 : 320mVrms/90k Ω
<Equalizer amplifier (Phono in ~ Rec out>
Maximum allowable input	Phono MM-1, 2 : 100 mVrms (1 kHz) Phono MC-2:10mVrms
Maximum power output	10 Vrms (at 50k Ω load)
Rated output	320 mVrms (at 50k Ω load)
RIAA deviation	20 Hz to 20 kHz ± 0.2 dB or less
<Control Amplifier (Aux2 in to Pre out, Defeat)>
Maximum power output	10 Vrms (at 50k Ω load)
Rated output	1 Vrms (at 50k Ω load)
Total harmonic distortion factor	0.01% or Less (20 Hz to 20 kHz, Rated Output)
Tone Control Section Frequency Characteristics	Tone defeat : 10 Hz to 150 kHz ± 0.5 dB or less Tone flat : 20 Hz to 20 kHz ± 0.5 dB or less
Tone control (Folding Point / Variable Range)	Each 2 dB step Bass : 320 Hz & 640 Hz / ± 10 dB (50 Hz & 100 Hz) Treble : 1.6 kHz & 3.2 kHz / ± 10 dB (10 kHz & 20 kHz)
Filter characteristic	Low cut : 15 Hz, 18dB/oct., Butterworth type High cut : 9 kHz, 18dB/oct., Butterworth
Loudness control	+ 6.5 dB (100 Hz), + 6 dB (10 kHz)
Muting	-20dB
<General>
Signal-to-noise ratio (IHF-A)	Phono MM-1, 2 : 78 dB or more (input short circuit) Phono MC-2 : 72 dB or more (input 40 Ω) Tuner, Tape PB, Aux : 100 dB or more (input short-circuit)
Channel separation (Phono2-SP)	70 dB or More (1 kHz or Less) 40 dB or More (20 kHz)
Power outlet	Switched : 2 systems, 250W Unswitched : 1 line, 150W
Pwer	100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law)	195W
External dimensions	Width 430x Height 140x Depth 350 mm
Weight	12.5kg