C.E.C. AMP 71

Second-hand, in good condition, it has some scratches (see pictures). Without its original package.

The AMP71 employs a single-ended circuit in which a single  transistor processes all the music signals. Unlike many other amplifiers, the AMP71 does not split the music signal by half a wavelength into the + and - sides. It also eliminates the dynamic range variation that occurs when transistors are arranged for each + - polarity.
In addition, by installing a unique LEF circuit, high-efficiency high-power with less heat generation is realized even though it is pure A class.

Since stable amplification with good linearity is possible by the LEF circuit, basically no NFB loop is required, and a straight and shortest signal path is realized by a completely non-feedback amplifier.

With a unique differential and full balance circuit design, the music signal is processed in a completely separate state from the input terminal to all areas of the volume control and power amplifier, and even to the speaker terminal.
In addition, it has a fully dual-monaural configuration, and with the exception of the AC power inlet, the power supply circuit with a 650 VA toroidal transformer is completely symmetrical from the input terminal to the speaker terminal.

The protection circuit is equipped with a monitoring circuit equipped with a high-speed protector that eliminates mechanical contact, and checks current, voltage, DC, offset, power supply circuit, etc.

The volume control mechanism uses a 100-step thin-film resistor with a high-precision single FET for switching between steps.
As a result, the channel balance is completely uniform on the right and left, and stability without change over time is obtained.

In addition to two balanced and four unbalanced inputs, there is an RCA tape output.
All input signals are switched by a pulse control relay located at the optimum position on the board.

Specifications

Output power 300W+300W (4ohms) 
200W+200W (8ohms) Class A
Input terminal XLR balance: Two lines 
RCA unbalance: Four lines
Output terminal Tape output: One line 
Speaker output: One line
S/N ratio 114dB
Gain 27dB (imbalanced input)
THD 0.018% or less
Dimensions Width 435x height 140x depth of 442mm
Weight 26kg