PL2 is a pure dualmonaural final, with a mosfet output stage.
To improve stereo separation, the two stages are completely independent of each other. To improve detail and image, the power stage and the signal stage have separate power supplies. To improve the matching between the two channels, the volume is adjusted with a 24-step switch, and precision resistors. To avoid any signal alteration, no tone adjustment is implemented.It is well known that every amplifier device, be it transistor, mosfet, or vacuum tube. especially in the final stage, introduces a distortion of the signal, which manifests itself as a veiling of the sound.
From the theory it is known that, if a high gain amplifier is built, and a high negative feedback is performed, the gain of the obtained amplifier becomes practically dependent only on the feedback element. Therefore if the feedback element is a precision resistor, you get an amplifier, with characteristics, practically ideal, free of the harmonic distortion of the elements that compose it, and whose gain is perfectly defined by the feedback resistor. Unfortunately, such an tempting theory is difficult to put into practice, since, the high gain and the high rate of feedback, tend to make the amplifier unstable, transforming it into an oscillator.
To avoid this, a compensation is made, which makes the amplifier more or less stable, but that lowers the response to the high frequencies, and introduces oscillations to the square wave.
PL audio, paying particular attention to the circuit realization, maximizes this theory, realizing the final PL2. Practically without distortion and oscillations, and with a frequency response that extends up to 200khz with attenuation of 1db.
On the side the square wave response, without oscillations, with PL1 speakers or 6Ω load.
Above the amplitude response, to the sine wave, with PL1, or 6Ω load, in the order at 2Hz, 1kHz, 200kHz.
- power 50wrms per channel on 8Ω.
- input sensitivity 1v @ 5kΩ
- frequency response 2hz – 200khz @ -1db
- power supply 230v-50hz