JBL SE408S 164,000yen(around the 1970 time)

Silicon transistor power amplifier with the output of 40Wx2.
An internal specification is almost the same as SE400S.
In order to use it, inserting in a speaker cabinet, a shelf, etc., it mainly has a structure without a cover.

The surface panel serves as a design as which the radiator of the transistor also served.

The scheme called Energizer is adopted.
A printed-wiring board is in the interior by this scheme, and it is this substrate,several kinds of circuitries are prepared according to the speaker system of JBL, and it has also become an equalizer with which a dumping factor a model number -- also controls the frequency characteristic including power amplifier and a loudspeaker in an ideal property by reputting.

The slot which inserts SE408 in an enclosure backplane is established in some loudspeakers of JBL. 

Form	Stereo power amplifier
Effective output	40W+40W (8ohms)
Frequency band	3Hz - 20000Hz
Input sensitivity	0.8-3V
S/N ratio	90dB
THD	0.15%(40W)
Dumping factor	27 (8ohms)
The semiconductor used	Transistor: 22 pieces Diode: 20 pieces
Dimensions	Width 378x height 110x depth of 160mm

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JBL SE400S 178,000yen(around the 1970 time)

Silicon transistor power amplifier with the output of 40Wx2.
An internal specification is almost the same as SE408S.
In SE408S, the fraction which was a front-view panel is a rear panel, and it has a structure which the cover attached to the overall, and has a structure in which an equalizer board appears from the acrylics part of the center of a whole surface panel.
The rear panel serves as a design as which the radiator of the transistor also served.

The scheme called Energizer is adopted.
A printed-wiring board is in the interior by this scheme, and it is this substrate,several kinds of circuitries are prepared according to the speaker system of JBL, and it has also become an equalizer with which a dumping factor a model number -- also controls the frequency characteristic including power amplifier and a loudspeaker in an ideal property by reputting.

It is in order to insert in SE408 for having been in the enclosure backplane of some loudspeakers of JBL. 

Form	Stereo power amplifier
Effective output	40W+40W (8ohms)
Frequency band	3Hz - 20000Hz
Input sensitivity	0.8-3V
S/N ratio	90dB
THD	0.15%(40W)
Dumping factor	27 (8ohms)
The semiconductor used	Transistor: 22 pieces Diode: 20 pieces
Dimensions	Width 378x height 110x depth of 160mm

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JBL SG520 268,000yen(around the 1970 time)

Control amplifier which did not use any rotated type thumb but consisted of only straight line type controls and push-button switchpoints.

Although the model number has not changed from the early model to the second-half model, the enhancement is added to the internal circuitry.

If a 1kHz testing tone oscillator is built in and the relay control F22 is combined with this, it is possible to perform the stereo sound-volume balance control called Aural Null Balancing System.

Although a front is an aluminum panel, there is SE520E which can change supply voltage by SG520G of the gold panel set by finish of power amplifier SE400S, and an expert model. 

Form	Stereo control amplifier
Output	3V
Frequency band	20Hz - 20000Hz
Input sensitivity	Phono:6mV AUX:300mV
THD	0.15
Tone control	High region: 20kHz and +21 -17 dB Low-pass: 20Hz, ±17dB
An attached circuitry	Loudness control With an NULL BALANCE

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JBL SA660 291,300yen(around the 1970 time)

An Integrated Amplifier with the output of 60Wx2.

As a modification from SA600, the tone control serves as a right-and-left independency.

The stream composition has a structure which left the basal line, respectively and made SG520 and SE400S simple. Moreover, the equalizer circuitry carried by SE400S is not carried.

The loudness control and the NULL BALANCE are carried

Form	Stereo Integrated Amplifier
Effective output	60W+60W (8ohms)
Frequency band	20Hz - 20000Hz
Input sensitivity	Phono: 4mV, 8mV, 16mV (switching type) AUX:250mV
S/N ratio	72dB
THD	0.2%
Tone control	High region: 20kHz, ±16dB Low-pass: 20Hz, ±18dB
Dumping factor	32 (8ohms)
The semiconductor used	37Tr, 23Di
Dimension	Width 412x height 128x depth of 350mm
Weight	11.8kg

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