The RQ-4748 is an updated version of the RQ-3748 which was released in 1973 and is the top of the line model for the RQ-4700 series of receivers.
Changes include an internal CD-4 De-modulator, removal of the Aux Input for a CD-4 Phono Input, and a red indicator overlay.
This model saw an introduction in Germany as the Saba 8280 Quadro in 1975. It was only sold briefly for the 1975 model year and possibly in early 1976 as well. At the time Saba was a subsidiary of GTE Inc.
Stereo Bridge Mode
Dimable tuner lights (High/Low)
Independent balance controls for each channel
Selectable Image Orientation
4 Channel modes supported internally include Discrete, SQ Matrix, SQ Blend, and CD-4
Supports two sets of four speakers while in 4 Channel mode or two sets of two speakers while in Stereo Bridge mode
Two 4 Channel Discrete Tape Monitors
Magnetic Phono Input
CD-4 Phono Input