Pioneer SA-9800

Commentary

A stereo pre-main amplifier developed by inheriting the design philosophy of SA-9900.

Like SA-9900, it adopts a side terminal system in which input / output terminals are arranged on the left and right panels.
As a result, the input terminal is completely integrated with the equalizer board to prevent degradation of the high-frequency characteristics caused by the shielding wire.

The power amplifier section uses a pure complimentary service OCL circuit directly connected to all stages. It consists of a single stage differential with ± 2 power supplies and a parallel push-pull configuration.
By making the load of the pre-driver constant current, the bare gain is increased, and by applying the optimum NFB, the distortion is reduced over a wide band. By using the power supply before the output stage as a stabilizing power supply, the transient crossover distortion at minute outputs is eliminated. By using the parallel push-pull output stage, the linearity of current characteristics is improved and distortion is reduced.
In addition, a differential amplifier and a bias compensation circuit are adopted to improve stability, so that fluctuation of offset voltage due to external temperature change is minimized.

The equalizer is equipped with a differential amplifier using a low-noise transistor can-shielded at the first stage to stabilize the output mid-point and improve the SN ratio. In addition, 100% DC NFB is applied to reduce distortion and improve stability.
In addition, the final stage SEPP operates in class A operation until large amplitude, enabling high output voltage to be extracted at a low distortion rate.
In addition, carefully selected high-precision elements are used to improve sound quality.

There are two Phono inputs, one of which is capable of level adjustment up to -12dB and 4-point switching of input impedance.
For level adjustment, NFB changes up to -6dB, and output volume changes from -6dB to -12dB.

The tone circuit is a 2-stage direct-coupled circuit. By using FET in the first stage, noise variation due to volume position is minimized. In addition, NFB is applied to the 2-stage direct-coupled circuit in both AC and DC, and is sent to the tone circuit in the next stage with low impedance, making it an ideal condition for tone circuit operation.
In addition, the voltage at the midpoint is stabilized by two power supply systems, plus and minus 24 v (total 48 v).

The volume uses a full-scale attenuator type volume with 22 contacts, and the use of high-precision printing resistors reduces gang errors.
It also has a 3-step lever type attenuator.

NFB type tone control is adopted, and 3-step turnover frequency switching is adopted to expand the control range.
It is also equipped with a tone on/off switch.

It is equipped with a duplicate switch that can dub tapes 1 to 2 and 2 to 1.

The power supply section is equipped with two large electrolytic capacitors of 18,000 μ F.

Equipped with low filter / high filter.

A protective circuit with a built-in relay is mounted to suppress noise when power is turned on/off.

The actual measurement data of each product is attached.

Model Rating

Type	Stereo pre-main amplifier
Power Amplifier Unit
Circuit system	Differential 1-stage all stages directly connected parallel PP pure complimentary service OCL
Effective output (both channels driven, 20 Hz to 20 kHz)	100W + 100W (4 Ω) 80W + 80W (8 Ω)
Harmonic distortion factor (20 Hz to 20 kHz)	0.1% or Less (Effective Output) 0.05% or Less (8 Ω at 40W Output) 0.05% or Less (8 Ω at 1W output)
Cross modulation distortion factor	0.1% or Less (Effective Output) 0.05% or Less (8 Ω at 40W Output) 0.05% or Less (8 Ω at 1W output)
Output Bandwidth (IHF, both channel drives)	5 Hz ~ 40 kHz (Distortion Factor 0.1%)
Frequency characteristic	10 Hz to 80 kHz + 0 -1dB
Input Sensitivity / Impedance	Power amp in : 1V/50k Ω
Output terminal	Speaker A / B : 4 Ω ~ 16 Ω Speaker A + B : 8 Ω ~ 16 Ω Headphone : 4 Ω ~ 16 Ω
Damping factor (20 Hz to 20 kHz)	30 or more
S/N	100 dB or more (IHF, A-network, short circuit)
Preamplifier Section
Circuit system	Equalizer amplifier : A class SEPP with 2 positive and negative power supplies, one stage differential and three stage direct connection Control amplifier : Positive and negative 2 power supply, first stage FET
Input Sensitivity / Impedance	Phono1 : 2.5mV/50k Ω Phono2 : 2.5 to 10mV/35k Ω, 50k Ω, 70k Ω, 100k Ω Tuner, Aux1, 2, Tape PB1, 2 : 150mV/50k Ω
Phono maximum allowable input (Harmonic distortion rate 0.1%, 1 kHz)	Phono1:250mV Phono2 : 250 mV to 500 mV
Output Level / Impedance	Tape Rec1, 2 : 150 mv Pre-out : 2V/1k Ω
Harmonic distortion factor (20 Hz to 20 kHz)	Not more than 0.05%
Frequency characteristic	Phono (RIAA deviation) : 30 Hz to 15 kHz ± 0.2 dB Tuner, Aux, Tape PB : 7 7 hz to 40 khz + 0 to 1 db
Tone control	Bass: ± 10 dB (25Hz/50Hz/100Hz) Turnover Frequency : 100Hz/200Hz/400Hz Treble: ± 10 db (8kHz/16kHz/32kHz) Turnover Frequency : 2kHz/4kHz/8kHz
Filter	Low : 15 Hz, 30 Hz, 12dB/oct. High : 8 kHz, 12 kHz, 12dB/oct.
Muting	0, -15dB, -30dB
S/N (IHF, A-network Short circuit)	Phono : 70 dB or more Tuner, Aux, Tape PB : 90 dB or higher
<General>
Semiconductor used	Transistor : 54 FET : 2 Diode, etc. : 26 pcs
AC outlet	Power switch interlock : 2 systems Power switch not linked : 1 system
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	190W (rated) 530W maximum
External dimensions	Width 420x Height 165x Depth 403 mm
Weight	17.2kg