Technics SH-3580

Commentary

A demodulator developed for CD-4 record reproduction.

A PLL (Phase Locked Loop) circuit is used in the FM detection circuit that extracts the difference signal by FM detection of the carrier signal.
This eliminates noise and distortion that can occur when the carrier level is low due to wear of the record, or when the carrier signal drops out due to dust.

It is equipped with a carrier level adjustment knob to compensate the output of 4 ch cartridge.

An IC is used for the equalizer circuit to obtain low noise, high gain, wide dynamic range, and to suppress the fluctuation of performance.

The phono jacks have three positions : Phono1 for semiconductor cartridges, Phono2 for magnetic cartridges, and Phono3 for ceramic cartridges.

The front panel is equipped with an adjustment knob for easy separation adjustment when replacing the cartridge.

Locking type selector is adopted as selector.
The SH 3580 is designed to supply a bias current to the semiconductor cartridge connected to Phono1 when the bias selector switch on the back panel is turned ON. In order to prevent a bias current from flowing when an MAG type cartridge is accidentally connected to Phono1, the selector does not turn to Phono1 unless the LOCK button is pressed.

Equipped with a COM terminal that can be shared by Phono1 and 2.
When a player is connected to this terminal, both semi-conductor and MAG type cartridges can be used separately with shell exchange only.

The function knob has three positions : 2 ch for conventional 2 ch record playback, 4 ch for discrete 4 ch record playback, and External for other 4 ch source playback connected to 4 ch in.
If you set it to the 2 ch position, the same sound as the front is played from the rear.

With a 4-channel volume, the volume of the 4 ch source can be adjusted with one volume. In addition, it is a preset type that once set, the rotation of the knob stops at that position.

Pre-out terminal is mounted.
This jack can be used as a 2-channel equalizer or as a recording jack.

Model Rating

Type	CD-4 System Disk Demodulator
Frequency characteristic	20 Hz to 15 kHz
Rated input level	Phono1 : 3 mv (For Semiconductor Cartridge) Phono1/2 : 3 mv (For Semiconductor Cartridge) Phono2 : 2 mv (For Magnetic Cartridge) Level Switch Low : 2 mv High:7mV Phono3 : 100 mV (For Ceramic and Magnesium Cartridge)
Rated output level	300mV
2-channel output	Pre out Low:3mV High:150mV
Input impedance	Phono1 : 2.2k Ω Phono1/2 : 100k Ω (Semiconductor : 2.2k Ω, Magnetic : 100k Ω) Phono2 : 100k Ω Phono3 : 1M Ω
Output impedance	500 Ω
Semiconductor used	IC : 10 Transistor : 42 Diode : 46 pcs
Fuse rating	0.5A
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	8W
External dimensions	Width 410x Height 140x Depth 330 mm
Weight	7kg
Attachment	Test record Steira screener