High level and quality power amplifier module. The amplifier is designed specifically for "sophisticated" lovers of high-quality audio.
Simple circuitry, using the so-called "current mirror" in the preliminary differential stage, allows you to minimize distortion and unconditionally bypass all microcircuit amplifiers in sound quality.
The module requires high precision drilling of holes, since the holes on the radiator must completely match the holes on the printed circuit board of the module, at the same time, this solution significantly saves space in the case and allows you to move the amplifier as far as possible from sources of electronic interference.
The amplifier is assembled on 1 pair of output transistors 2SA1943 and 2SC5200 TOSHIBA.
When using 8 ohm acoustics, the supply voltage can be raised to 45-50V to obtain the equivalent power at 4 ohms.
The module is easy to set up and requires only setting the quiescent current on a warm amplifier, depending on the supply voltage. The optimal quiescent current of the output stage is 60-120mA. It makes no sense to put it higher - neither the instruments, nor the tangible changes occur by ear. To set the quiescent current, the voltage on a pair of emitter resistors of the final stage is measured and set in accordance with the calculation formula (see product photo). It should also be taken into account that the quiescent current, due to the thermal stabilization circuit, is not constant and changes depending on the temperature of the radiator, so you need to remember about pauses for cooling / heating the radiator to operating temperature.
For passive cooling at a supply voltage close to the maximum and a quiescent current of up to 100 mA, a radiator of at least 750 sq. cm is required
Subjectively, the amplifier bypasses all microcircuit amplifiers and sounds at the level of very expensive transistor "brothers", which is also confirmed by our measurements.
The module can be recommended for building a high-quality power amplifier and working on any acoustics with the appropriate power.
Under the order, it is possible to assemble this amplifier with the following pairs of output transistors:
TTA1943 and TTC5200 - TOSHIBA
2SA1302 and 2SC3281 - TOSHIBA (Dismantling)
MJL21193 and MJL21194 - MOTOROLA
FJL4215 and FJL4315 - MOTOROLA
NJW0281 and NJW0302 - MOTOROLA