Currently on the market are a large number of active speakers for PCs but speaker sound quality is at least not lower than 15 ° C, to many can’t afford. The vast majority makes the choice in favor of cheap small speakers, the sound of which quite corresponds to the price, but…
It is well known that the average user of the time communication with a PC, almost half is spent on computer entertainment. Play (listen to music, watch videos) best in headphones, so as not to annoy others. We must remember that the sound is 3D AKTION many causes resentment, even if the column type GENIUS-SP205B: because at normal volume noises begin to play the main signal. In addition, not every sound card has a separate output for headphones, not to mention the regular built-in switch speaker/HEADPHONE.
Since the computer of the author of these lines — integrated sound card, devoid of many custom amenities by reason of the austerity of the place on the motherboard, had to get out. Completely redo the nominal amplifier (SHU) had no meaning, as it inevitably would entail the additional (and significant!) costs and difficulties in manufacturing of the printed circuit Board with a specific location of the power button, jacks for headphones, volume control. It was decided to confine the production of mini-subunit headphone. And for those who need spare parts suggest the store computer technician.
As the basis of such a device used by domestic IC К548УН1А, which is a dual channel low noise amplifier for low-frequency high-quality Studio and household radio. Microchip has a wide range unipolar voltage: 9 to 30 V, protected against short circuit and internal stabilizer in the power supply circuit. The separation between channels is 60 dB.