Pioneer SA-620

Commentary

In line with the original purpose of the pre-main amplifier, this model is designed with full functionality and sound quality as the goal.

The equalizer amplifier uses a 2-stage direct-coupled circuit with transistors that further select the low-noise type to improve S/N and stability.
In addition, high-precision parts (resistors and capacitors) are used in order to reproduce the recording characteristics of the record with fidelity.

It is equipped with two Phono terminals and two pairs of terminals for tape decks so that two tape decks can be connected at the same time.

With a built-in microphone mixing amplifier, you can mix and play the program source and the sound from the microphone.
The mixed signal can be taken out from the Tape Rec jack (DIN jack), so you can also record by connecting a tape deck.
It can also be used as a simple microphone loudspeaker device.

The tone circuit is a 2-stage direct connection NFB type with three carefully selected transistors.
By adopting the emitter follower circuit, the flat position of the tone control knob provides a simple characteristic with less waviness.

All stages of the power amplifier are directly connected with pure complimentary service system.
A differential amplifier is adopted in the first stage and a high DC stability is obtained by using an input bias compensation circuit in combination with the amplifier. In addition, a large radiator and a power transistor with high breakdown strength are used to provide ample room even at high power.

Equipped with two types of speaker terminals, each can be driven separately or simultaneously.

It is fully equipped with functions such as muting switch, high filter, loudness contour, pre-main separation switch, etc.

Model Rating

Type	Stereo pre-main amplifier
Power Amplifier Unit
Circuit system	Semi-differential complimentary service OCL system
Effective power	Single channel drive 1 kHz : 22W/22W (8 Ω), 27W/27W (4 Ω) Both channel drive 20 Hz to 20 kHz : 15W + 15W (8 Ω), 15W + 15W (4 Ω) 1 kHz : 18W + 18W (8 Ω), 22W + 22W (4 Ω)
Harmonic distortion factor	Effective power : 0.5% or less 0.1% or less at 1W output
Cross modulation distortion factor	Effective power : 0.5% or less 0.1% or less at 1W output
Output bandwidth	10 Hz ~ 70 kHz (IHF, double-channel drive, 0.5% distortion factor)
Frequency characteristic	15 Hz ~ 80000 Hz + 0 -1dB
Input Sensitivity / Impedance	Power Amp In : 500mV/50k Ω
Output terminal	Speaker : A, B, A + B (4 Ω ~ 16 Ω) Head Phone : 4 Ω ~ 16 Ω
Damping factor (1 kHz, 8 Ω)	30 or more
S/N	90 dB or more (IHF, short circuit A network)
Residual noise (8 Ω, pre + power amplifier)	1 mV (0.13 μ W) or less
Preamplifier Section
Circuit system	Equalizer amplifier : 2-stage direct connection NFB type Control Amplifier : NFB Type
Input Sensitivity / Impedance	Phono1, 2 : 2.5mV/50k Ω MIC : 7.5mV/30k Ω Tuner, AUX1, 2, Tape Monitor1, 2 (DIN) : 150mV/100k Ω
Phono maximum allowable input (rms/P-P)	100mV/280mV
Output Level / Impedance	Tape Rec1, 2 : 150mV/1.4k Ω Tape Rec2 (DIN) : 30mV/80k Ω Pre Out : 500mV/4.7k Ω
Harmonic distortion factor (20 Hz to 20 kHz)	Not more than 0.2%
Frequency characteristic	Phono (RIAA deviation) : 30 Hz to 15 kHz ± 0.5 dB Tuner, AUX, Tape Mon : 15 Hz to 30 kHz ± 1 dB
Tone control	Bass : ± 10.5 dB (100 Hz) Treble : ± 10.5 dB (10 kHz)
High filter	4 kHz, 6dB/oct.
Loudness contour at volume -40dB	+ 10 dB (100 Hz), + 6 dB (10 kHz)
Signal-to-noise ratio (IHF, short circuit A network)	Phono : 75 dB or more MIC : 80 dB or more Tuner, AUX, Tape Mon : 90 dB or higher
Muting	-20dB
<General>
Semiconductor used	Transistor : 28 Diode : 11 units
Power supply voltage	100 VAC, 50Hz/60Hz
Power outlet	Power switch interlock : 1 system Power switch not linked : 2 systems
Power consumption	Rating : 45W Maximum : 110W
External dimensions	Width 415x Height 132x Depth 328 mm
Weight	7.9kg