JBL SE408S
¥ 164,000 (around 1970)
Commentary
Silicon transistor power amplifier with 40Wx2 output.
The internal specifications are almost the same as those of the SE400S.
It has a structure without a cover because it is used by fitting it into a speaker cabinet or shelf.
The surface panel is also designed as a radiator for the transistor.
A method called Energizer is adopted.
In this method, there is a printed circuit board inside. This board is provided with several types of circuits depending on the JBL speaker system. It is also used as an equalizer to control the frequency characteristics (including the damping factor depending on the model number) of the power amplifier and speakers to the ideal characteristics.
Some JBL speakers have cutouts to fit the SE408 into the back of the enclosure.
Model Rating
| Type | Stereo power amplifier |
| Effective power | 40W + 40W (8 Ω) |
| Frequency band | 3 Hz to 20000 Hz |
| Input sensitivity | 0.8 ~ 3 V |
| Signal-to-noise ratio | 90dB |
| Total harmonic distortion factor | 0.15%(40W) |
| Damping factor | 27 (8 Ω) |
| Semiconductor used | Transistor : 22 Diode : 20 pcs |
| External dimensions | Width 378x Height 110x Depth 160 mm |