DENON PMA-300ZA

Commentary

An improved pre-main amplifier based on PMA-300Z.

The power amplifier is a pure complimentary service circuit using a PNP NPN pair of silicon power transistors manufactured by Motorola of the United States, known for their excellent characteristics and durability.
The driver stage is Darlington connected, and all stages from the input terminal to the speaker terminal are directly connected OCL circuits.

The equalizer amplifier section is a 3-stage direct-coupled E-E negative feedback type using a low-noise NPN transistor. A high collector voltage of + 38 v provides a high allowable input, while a small and appropriate collector current provides a low noise level, providing a wide dynamic range.

The Phono input has two systems with different sensitivities, and can be used depending on the sensitivity of the cartridge.
The input sensitivity is set by changing the negative feedback amount of the equalizer amplifier. The amplifier gain is 32 dB for PHono1 and 22 dB for Phono2.

Equipped with Pre out and Main in jacks that can separate the Pre and Main.

Equipped with tone control.
The tone amplifier section uses a 2-stage direct connection circuit with a low-noise NPN on the first stage and an FET transistor on the second stage. The tone control is performed by changing the negative feedback by the volume. The emitter-follower circuit is also directly connected to the tone amplifier section so that the characteristics of the circuit are not affected by the output load.
The control volume has a special resistance curve with an 11-position click stop, giving a stepped curve and feel with a rotary switch, while retaining the inherent advantages of the volume type in which the curve can be continuously adjusted.

Equipped with low-cut filter and high-cut filter.

Equipped with a -20dB muting switch.

Equipped with a loudness control.

The protection circuit at the final stage adopts a current limiting method and is designed so that it does not exceed the safe operating range of the power transistor even when the load is short-circuited.

Model Rating

Type	Integrated amplifier
Power Amplifier Unit
Circuit system	Pure complimentary service 2 power supply OCL circuit directly connected to all stages
Rated output	17W + 17W (8 Ω, THD 0.1% or less when both channels are operated) 19W/19W (8 Ω, single-channel operation, THD 0.1% or less)
Total harmonic distortion factor	0.1% or Less (at Rated Output)
Intermodulation distortion factor (60 hz : 7 khz = 4 : 1)	0.1% or Less (Sine Wave, Amplitude Output Equivalent to Rated Output)
Output bandwidth	20 Hz to 20 kHz -1dB (THD 0.1%)
Frequency characteristic	10 Hz to 100 kHz + 0 -1dB
Input impedance	60k Ω ± 20%
Input sensitivity	1 Vrms (at rated output)
Residual noise	0.3 mVrms or Less (Input Terminal Short Circuit)
Output impedance	0.12 Ω or Less (5 Hz ~ 30 kHz, DF70 or More)
Preamplifier Section
Maximum power output	Equalizer Amplifier : 9 V or More (THD 0.1% or Less) Tone control amplifier : 5 V or more (THD 0.1% or less)
Total harmonic distortion factor	Equalizer : 0.03% (100, 1k, 10 khz, output 1 v)
RIAA deviation	Phono1 : 30 Hz to 15 kHz ± 0.8 dB
Input Sensitivity / Impedance	Phono1 : 2.4mVrms/60k Ω ± 20% Phono2 : 8mVrms/60k Ω ± 20% Tuner, AUX : 100mVrms/80k Ω ± 20% Tape (including DIN) : 500mVrms/120k Ω ± 20%
Phono maximum allowable input (1 kHz)	Phono1:240mVrms Phono2:600mVrms
Signal-to-noise ratio (IHF-A)	Phono1 : 70 dB or more Phono2 : 77 dB or more Tuner, AUX, Tape : 85 dB or more
Output Level / Impedance	Tape rec : 100mVrms/1k Ω or less DIN terminal : 40mVrms/80k Ω or less
Tone control	Bass : ± 11 dB (80 Hz) Treble : ± 9.5 dB (12 kHz)
Filter	Low Filter : 100 Hz, 6dB/oct. High Filter : 7 kHz, 6dB/oct.
<General>
Accessory terminal	Pre out : 1V/200 Ω Main in : 1V/60k Ω Headset : Compatible with 8 Ω stereo headphones
Semiconductor used	NPN transistor : 23 pcs PNP transistor : 6 pcs FET : 2 Diode : 9 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