YAMAHA UD-500
Price unknown (around the early 1970 s)
Commentary
Quad riser amplifier for 4-channel conversion from 2-channel stereo system.
4-2-4 method, 2-4 matrix circuit クォドライザー is mounted.
It is also possible to adjust the individual level of four channels or the total volume of all channels to accommodate the circuit configuration of a 2-channel stereo system.
You can use the tape monitor switch of a stereo system or amplifier, or the pre-out / main in jacks for connection.
There is a built-in 50W power amplifier for the rear amplifier. This amplifier can be used independently as a sub amplifier.
4-channel effects such as Hall and Surround, and a Discrete position for playing 4-channel tapes.
There are two channel and four channel tape monitor switches with a built-in high-cut filter.
Model Rating
| Type | Quad riser amplifier |
| Dynamic Power | 50W(IHF) |
| Effective power | 15W/15W |
| Load impedance | 4 Ω ~ 16 Ω |
| Frequency characteristic | 20 Hz to 40 kHz -3dB |
| 4-ch decoder | Surround : matrix method Hall : phase shift system |
| Other | 2-4ch tape monitor available Total volume 4-ch volume |
| Pwer | AC100V |
| Maximum Power Consumption | 80W |
| External dimensions | Width 260x Height 140x Depth 300 mm |
| Weight | 4.5kg |