31 July 2018

Technics SE-A3 / SU-A4 - Professional Series DC Power Amplifier

Professional Series DC Power Amplifier

The Technics SE-A3 power amplifier introduced in 1980 employs a New Class A circuitry that makes it something special. New Class A is a unique Technics design that provides the distortion-free fidelity of class A amplifiers and the high power efficiency of class B (or AB) amplifiers. The SE-A3 delivers a rated output of 200 watts per channel, both channels driven into 8 ohms, with no more than 0.002% total harmonic distortion from 20 to 20,000 Hz. Signal-to-noise ratio is 123 dB (IHF '66) and TIM is so low that it is unmeasurable. Although these specifications speak for themselves, the New Class A circuitry eliminates the switching distortion and crossover distortion that are characteristic of conventional amplifiers with the use of the original "synchro bias" circuit. To eliminate chances of cross-channel interference the SE-A3 is equipped with separate transformers for the left and right stereo channels. To complement the overall aesthetics this power amplifier uses large Peak Power Meters that have an attack time of only 50us and give direct readings from 0.0001W to full power. We can almost consider this a Technics trademark. Unfortunately rumour is that there are two types of Technics SE-A3, one that is broken while the other one will be soon broken. The good news however is that the special DLPT symmetrical configuration dual transistors can be replaced with two independent Toshiba power transistors.

Professional Series DC Power Amplifier

Professional Series DC Power Amplifier

Professional Series DC Power Amplifier

Professional Series DC Power Amplifier

Professional Series DC Power Amplifier

Professional Series DC Power Amplifier