SANSUI CA-3000

Commentary

Aiming for the highest level of control amplifier, this control amplifier is equipped with excellent basic performance and extensive adjustment functions.

The EQ section uses a + -2 power supply and a class A pure complimentary service push-pull system with a CR-NF type 2 amplifier configuration. The circuit consists of two dual FETs per channel and 11 low-noise transistors.
This circuit emphasizes dynamic characteristics such as phase characteristics, dynamic range, and signal-to-noise ratio, while limiting correction of RIAA deviation, which affects sound quality, to ± 0.2 dB.
Compensation for RIAA deviation is generally performed with an NF-type circuit. However, with the CA 3000, high-frequency compensation is performed with the CR-type and low-frequency compensation is performed with the NF-type, so there are no peaks or phase shifts that tend to occur in high-frequency ranges, and sound quality with a high SN ratio is achieved.
This circuit is driven by a high voltage of + - 50 V supplied from a constant-voltage power supply independently on the left and right sides, and has a high maximum allowable input.

A toroidal transformer is used for the power supply section, and all stages are independently stabilized on the left and right sides to prevent interference between channels and blocks.

The tone controls feature a unique triple tone control that adds a midrange to the normal bass / treble. The high and low turnover frequencies can be switched in three stages, and the tone amplifier can be passed by a defeat switch.
The tone amplifier uses carefully selected low-noise transistors and high-precision CR elements. There is no increase in distortion component even when boosted, and sufficient amount of NF is applied. A wide dynamic range and high SN ratio are obtained.

It is equipped with a level meter by logarithmic compression circuit.
This level meter the dynamic range, output of dynamic range, output of the power amplifier, level matching with the deck, etc. with the changeover switch.

The Phono input has a switching function that allows switching between three levels of impedance and three levels of input sensitivity.
Also, the input capacity can be switched to 3 levels.

It uses a stepless precision volume with less interlocking and variation error comparable to an attenuator.

Three tape decks can be recorded simultaneously, two can be copied simultaneously, and independent source play and copy can be performed.

Equipped with a 2-stage low / high filter, 3-stage audio muting, 5-stage mode switch, headphone jack / level, etc.

Actually measured data sheets are attached to each unit.

Model Rating

Type	Stereo control amplifier
Total harmonic distortion factor (rated output)	Not more than 0.03%
Intermodulation Distortion Factor (70 Hz : 7 kHz = 4 : 1, SMPTE)	Not more than 0.03%
Output impedance	47k Ω
Frequency characteristic	10 Hz ~ 100 kHz + 0.5 -1dB
RIAA deviation (30 Hz to 15 kHz)	+ / - 0.2 dB
Channel separation (rated output)	Phono1, 2, Tuner, Aux : 60 dB or more Tape Mon1, 2, 3 : 60 dB or more
Hum and noise	Phono1, 2 : 70 dB or more Tuner, Aux, Tape mon1, 2, 3 : 90 dB or more
Input Sensitivity / Impedance (1 kHz)	Phono1 : 1.5 mV, 3 mV, 6mV/30k Ω, 50k Ω, 100k Ω Phono2 : 1.5 mV, 3 mV, 6mV/50k Ω (maximum allowable input 1,000 mV, THD0.1%) Aux, Tuner, 130 mv Tape Monitor1, 3 (Pin) : 130mV/50k Ω Tape Monitor2 (Pin/Din) : 130mV/50k Ω
Output voltage	Tape rec1, 3 (Pin) : 130 mV Tape rec2(Pin/Din):130mV/30mV Pre output : 1.3 V Pre output (maximum output, THD0.1% or less) : 8 V
Tone control	Bass : ± 10 dB (50 Hz) Midrange : ± 5 dB (1 kHz) Treble : ± 10 dB (20 kHz)
Tone selector	Bass : 100 Hz, 200 Hz, 400 Hz Treble : 2 kHz, 4 kHz, 8 kHz
Low filter	-3dB at 20 Hz, 12dB/oct. -3dB at 40 Hz, 12dB/oct.
High filter	-3dB (7 kHz), 6dB/oct. -3dB at 12 kHz, 12dB/oct.
Muting	0, -10dB, -30dB
Rated power consumption	50W
External dimensions	Width 460x Height 178x Depth 373 mm
Weight	13.3kg