DENON PMA-760

Commentary

This is a stereo pre-main amplifier developed by inheriting the technology of PMA-790 such as a 0 db power amplifier with no feedback.

Equipped with a non-feedback 0 db power amplifier that eliminates negative feedback loops.
This system is an application of the non-feedback technology developed in POA-8000, and uses a direct distortion servo circuit. The direct distortion servo circuit compares the input signal with the signal obtained from the output side (main signal + distortion component) to detect only the distortion component, and then applies the inverted phase of this distortion component to the input side.
This action drives the static distortion into the 0 region, and the noise appearing at the output side of the amplifier is treated as a difference from the input signal and is removed in the same way as the distortion component.
As a result, there is no signal feedback and no time delay, so the dynamic distortion which affects the auditory quality is suppressed. In addition, since there is no NFB circuit, it is not affected by the back electromotive force from the speaker, so the increase and generation of the distortion when the speaker is connected are suppressed.

A Pc200W power transistor is used in the final stage of the power amplifier section, and the direct A-class amplifier system achieves both A-class quality and B-class efficiency.

The entire signal path from the input terminal for the MC cartridge to the output terminal of the speaker uses a complete DC configuration without using a coupling capacitor.

The power supply consists of a large toroidal transformer of 260 VA, a large capacitor of 30,000 μ f, and a fast recovery diode of high-speed rectification with reduced switching distortion.

To bring out the performance of the MC cartridge, a super equalizer is used in the equalizer section.
As a result, the RIAA deviation of 20 hz to 100 khz ± 0.2 db has been achieved.

Equipped with tone control and high-speed protection circuit.

Model Rating

Type	Pre-main amplifier
Power Amplifier Unit
Circuit system	Non-feedback 0 db power amplifier system
Rated output (both channel drive Sine wave continuous output, 20 Hz to 20 kHz)	150W + 150W (6 Ω) 125W + 125W (8 Ω)
Input Sensitivity / Impedance	150mV/47k Ω
Total harmonic distortion rate (20 Hz to 20 kHz)	0.003% or Less (at Rated Output -3dB)
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	0.002% or Less (at Rated Output Equivalent Amplitude Output)
TIM distortion factor	Below the measurement limit
Slew rate	± 300 V / μ s or more
Output Bandwidth (IHF, both channel drives)	5 Hz ~ 80 kHz (THD 0.025%)
Frequency response (at 1W output)	1 Hz ~ 250 kHz + 0 -3dB
Output Impedance (1 kHz)	0.1 Ω
Output terminal	Speaker AORb : 6 Ω ~ 16 Ω Speaker A + B : 12 Ω ~ 16 Ω Headphone : 490mW/8 Ω
Preamplifier Section
Circuit system	Super equalizer system
Input Sensitivity / Impedance	Phono MM : 2.5mV/47k Ω Phono MC : 0.2mV/100 Ω Tuner, DAD/Aux, Tape : 150mV/47k Ω
Maximum Output / Rated Output	12V/150mV
RIAA Deviation (MC)	20 Hz to 100 kHz ± 0.2 dB
Total Harmonic Distortion Factor (at 1 khz, 8 v output)	Not more than 0.002%
<General>
SN ratio (IHF-A, input short circuit)	Phono MM : 87 dB at 2.5 mV input Phono MC : 70 dB (at 0.25 mV input) Tuner, DAD/Aux, Tape : 110 dB at 150 mV input
Tone control	Bass : ± 8 dB (50Hz/100Hz) Treble : ± 8 dB (10kHz/20kHz)
Subsonic filter	20 Hz, 6dB/oct.
Muting	-20dB
Loudness property	Low frequency : + 7 dB (100 Hz) High frequency : + 6 dB (10 kHz)
Pwer	100 VAC, 50Hz/60Hz
Power consumption (Electrical Appliance and Material Control Law)	230W
External Dimensions (including legs, knobs, terminals)	Width 470x Height 132x Depth 413 mm
Weight	12kg