Audio Database


900,000 yen(one set, a release time -unknown)

Tube monophonic power amplifier which supplied the newest electro technology and was developed.

SA-4 is the OTL (output transformer-less) power amplifier which does not carry the output transformer used with common tube power amplifier.
There are a SEPP type of one power source, a SRPP type, a SEPP type that supplies positive/negative 2 power source, and also an OCL (output capacitor Les) type of OTL amplifier which omits an output capacitor, supplies positive/negative 2 power source, and maintains the middle point at zero potential. In SA-4, the OCL composition which carried out direct coupling of an output pipe and the speaker is adopted, and not only an output transformer but an output condenser is not carried.
This has eliminated bad influences, such as a wire wound resistor by an output transformer, and stray capacitance of a disclosure inductance and a wire wound.

In order to prevent direct-current ingredient flowing into a speaker instead of an output condenser, the servo amplifier system original with SA-4 is carried. When direct current flows exceeding the allowable level which are 30mV - 90mV which IC memorized, this servo amplifier operates, and this says that SA-4 and a speaker are intercepted in an instant, and has prevented breakage of a speaker beforehand.

The auxiliary system which carried out coupling of the capacitor which cuts 16Hz or less is also carried.

The output stage consists of eight 6LF6.

The powerful power source which can ensure a stable supply of 1kW is carried in the power-source part.

The ammeter for bias adjustment and a meter selector, and half-fixed trimmer potention meter are carried in the front panel, and the check of the current bias of each output pipe or idle current can be performed.

There was also a black model besides a silver model.

Rating of a mode
Form Tube monophonic power amplifier
Output 140W (8ohms)
280W (16ohms)
Frequency bandwidth 0.1Hz - 50kHz
Distortion 0.1% or less (at the time of the maximum except take-off)
0.02% (at the time of 20W output)
Valves employed ECC83
Power supply voltage AC100V, 50Hz/60Hz
Power consumption 200W (at the time [ Usually ] of use)
Dimensions Width 480x height 170x depth of 480mm
Weight 26kg