The pages of professional journals have been published for several amplifier suitable for the PC. Authors are usually trying to maximize performance. When gaming or watching movies will enhance the overall quality audio experience. For routine work on the PC, when you need only listen to messages about a particular program is a power amplifier watts wasted tens of luxury. Hereinafter described amplifier with low power can be connected to any PC with audio output. Can be powered directly from a PC without having a computer in any way.



The amplifier is built on a printed circuit board according to Figure 2 and 3. SMD resistors and capacitors are mounted on the circuit, other components are solder normally. Disk is in a box KM27 laced a headphone jack and a potentiometer bracket to the side of the box. In the absence of other suitable connectors for connecting the speakers I use RCA connectors. To connect the input signal can be used jack 3.5 mm (the box is not fit) or cablet connector. For this amp I used a 4-wire shielded cable. Two cores are used for audio signal is the residual supply voltage. Supply voltage is taken from the game port on the first pin Ground wire (0 V) is connected to the fourth pin Current connections to the country konktoru game port and audio output from the PC establishes the involvement of ground loop, the realized sample, however, does not add any distracting.



The amplifier I made a miniature speaker cabinets that I planted a Speaker 57 mm diameter of the PC boxes. Although I was picked from eight pieces, I found two applicable. About half of them were scrubbed, the rest had each a different color sensitivity and other audio. I finally finished boxes have already used the miniature speakers with a plastic membrane purchased GES in the store. Best would be to use the medium to larger elliptical speakers with Alnico magnet (small round), which have a low stray field. These can sometimes get reprodukrory in selloffs or can Now unscrew the old television sets.



Amplifier, we will renew preferably with an external source, just as "Flat" battery. It is important that the power supply should never short-circuit. Collection of load should be up to 5 mA, when excited, then to 200 mA (at 5 V supply). Involvement has no guile, and it should work on the first circuit. The amplifier can also be used in conjunction with a Walkman or Discman. In this case, the need for an external power source - battery or AC adapter.



Miniature speakers I swapped for a bigger litter box with elliptical speakers (used for TV) with much better sound. The original "correction" emphasizes low frequencies, then stopped suit. Figure 4 is a modified engagement, changes are marked in red. In Figure 5 is a frequency response of the low frequencies before and after treatment.



BOM components



R1, R2, R5, R6 22 Ohm (SMD 1206)
R3, R4 2.2 Ohm (SMD 1206)
R7, R8 4.7 Ohm (SMD 1206)
P1 4.7 Ohm, potentiometer logarithmic stereo Radiohm
C1, C2, C7, C8, C9 100 nF (SMD 1206)
C3, C4 100 μF/10 V
C5, C6 470 μF/10 In
C10 In 1947 μF/16
IO TDA2822M
connector 3.5mm stereo jack socket SCJ-0354-5PU
Connectors 2x RCA
connector 3.5mm stereo jack plug
connector CANNON 15M
box KM27
shielded cable
PCB bcs37