SONY SQD-2050

Commentary

A 4-channel SQ decoder that supports all SQ, RM and discrete methods.

With five system push buttons, you can play all four channels.
In the SQ position, the built-in SQ logic decoder is used to extract 4-channel information, and in the R-MTX position, the built-in decoder conforming to the built-in RM method is used to play RM records in the best condition.
The 2-4 position allows you to play back stereo records with a 4-channel holetone effect, and the 2 ch position allows you to play back stereo records as they are on channel 2.
In the DISCRETE position, you can play 4 ch tape decks or discrete records by connecting a demodulator.

Uses a front back logic circuit.
The SQ method is originally superior in front left / right and rear left / right separation, and is theoretically infinite as in conventional two channel recording, but crosstalk occurs between the front center and the rear center.
To solve this problem, a front-back logic circuit has been employed to reduce crosstalk and achieve excellent separation and localization of SQ records.

A 4-channel master volume is installed.
By adjusting the level of each channel in advance, you can adjust the volume with one volume.

The back channel can be adjusted with the level adjustment volume on the back side, and a power amplifier can be connected directly.

Equipped with front back balance, front and back level balance can be easily adjusted.

Model Rating

Type	SQD matrix 4-ch decoder
Circuit system	SQ Decoder with Front Back Logic RM Decoder
Harmonic distortion factor	Not more than 0.2%
Frequency characteristic	20 Hz to 20 kHz ± 3 dB Others : 10 Hz to 50 kHz ± 3 dB
Input Sensitivity / Impedance	Input (SQ, R-MTX, 2 → 4) : 250mV/50k Ω 2 ch Tape : 750mV/100k Ω Discrete : 750mV/100k Ω
Output Level / Impedance	Front Out : 750mV/10k Ω Back Out : 2 V (maximum volume) / 10k Ω Rec Out:250mV
SN ratio (SQ separation)	80 dB (input 250 mV, A network) LF-RF:20dB LB-RB:14dB CF-CB : 10 dB (input 250 mV, 2 kHz)
Semiconductor used	Transistor : 22 IC : 2 Diode : 16 pcs
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	4W
External dimensions	Width 119x Height 157x Depth 312.5 mm
Weight	3.1kg
Attachment	Connection code RK-74x3