DENON PMA-300Z

Commentary

This is a pre-main amplifier that has taken over the quality of PMA-300 as it is, and is more complete.

Based on the design policy of "excellent bare characteristics and moderate negative feedback", it uses a genuine complimentary service circuit (genuine complementary symmetrical output) with a PNP / NPN pair of silicon power transistor from Motorola USA.
As a result, a complimentary service Darlington circuit with perfect symmetry is obtained.

The smaller the output impedance of the main amplifier, which short-circuits the back electromotive force generated by the voice coil of the speaker, the better the damping.
The direct coupling of the two power supply system adopted in the PMA-300Z takes into consideration that the damping does not worsen even in the ultra-low frequency range, and the damping factor shows a sufficient value even outside the audible band.

It uses an output capacitorless (OCL) circuit that directly drives the voice coil of the speaker with a two power supply system.
In addition, in order to increase DC stability inside the device, a differential amplifier using a carefully selected monolithic IC is adopted. By using an IC with the same accuracy as that used in the amplifier circuit of the measuring instrument as an active device, it is combined with the uniform symmetry of four transistors constructed on the same silicon substrate, and stable operation is enabled.

The tone control section uses a 3-chip NF-type circuit with an FET in the middle stage.
The collector current of the first stage transistor is reduced so that operation is performed in a low noise level region. The 40 v power supply voltage, which is equivalent to that of a preamplifier, provides efficient dynamic range and linearity, and high S/N sound quality.

Model Rating

Type	All-silicon transistor stereo premain amplifier
Power Amplifier Unit
Circuit system	Genuine complimentary service SEPPP OTL OCL circuit
Music power	22Wx2 (8 Ω)
Rated output (when THD is 0.1% or less)	Single-channel Drive : 19W/19W (8 Ω) When both channels are driven : 17W + 17W (8 Ω)
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	0.1% or Less (at Rated Output)
Frequency response (at 1W output)	10 Hz to 100 kHz -1dB
Output Bandwidth (0.1%)	20 Hz to 20 kHz -1dB
Input impedance	60k Ω
Input sensitivity	1 V (input required for output 12 V)
Damping factor	70 or More (8 Ω, 5 Hz to 30 kHz)
Residual noise	0.1 μ W or Less (8 Ω)
Preamplifier Section
Maximum power output	5 v (Harmonic Distortion Factor 0.1% or Less)
Harmonic distortion factor (output 1 v)	0.03%(100Hz) 0.03%(1kHz) 0.03%(10kHz)
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	0.1% or Less (at Rated Output)
Frequency characteristic	10 Hz to 100 kHz ± 1 dB
Input sensitivity	Phono1 : 2.4mV/60k Ω Phono2 : 8mV/60k Ω Tuner, AUX : 100mV/80k Ω
Maximum Undistorted Allowable Input (1 kHz)	Phono1:240mV Phono2:600mV
Equalizer characteristics	RIAA deviation within ± 0.8 dB
Recording and reconnector	REC/PB (DIN terminal) Input sensitivity : 500 mV Output level : 40 mv
Tone control	Bass : 80 Hz, ± 11 dB Treble : 12 kHz, ± 9.5 dB
Filter	Low Filter : 100 Hz, -6dB/oct. High Filter : 7 kHz, -6dB/oct.
<General>
Input terminal	Phono1, 2 Tuner, AUX, Main Input, Tape Play (RCA jack)
Output terminal	Rec Out Speaker Out (2 systems) Pre Amp Out
Semiconductor used	Transistor : 25 Diode : 14 pcs
Power supply voltage	100 VAC, 50Hz/60Hz
Power supply fuse	2.3A
Power outlet	Total 350W Power switch interlock : 1 system Power switch not linked : 1 system
Power consumption (Electrical Appliance and Material Control Law)	42W
External dimensions	Width 376x Height 140x Depth 302 mm
Weight	7kg