2 x 220W RMS Audio Amplifier

This amplifier is of such high quality that it would be an understatement to call it a HIFI amplifier. According to HIFI-confirmed-Finland, the frequency response must be direct and distortion <1% 20-20 kHz. Our power amplifier circuit meets the above requirements for bandwidth 5Hz - 500 kHz, however, the frequency band is limited to prevent interference. The amplifier meets the requirements for a reference amplifier, which is suitable for measurement and comparison operations. Small 12-24V voltage system amplifiers operating in the power and properties are somewhat modest, for instance, testing decent speakers. The amplifier is also suitable for demanding PA use.

When music occurs at shallow close 20Hz sound levels, the whole amplifier power reserve may need to be temporarily used. This happens especially when the low-frequency emphasis equalizer or amplifier is used, for example, TV. Watching a movie with lots of sound effects, if the power is not enough in that situation, the sound from the speakers is distorted, reducing the enjoyment of hearing or even damaging the speaker drivers.

The distortion of human hearing range is only about 20 Hz-20 kHz. The hi-fi speaker gamut extends at its best to 25kHz and the hearing area of bats "remains" at 150 kHz, so what are the practical benefits of the amplifier's superior frequency characteristics? The power of less than 1% distortion mentioned in the title 220W blue means the so-called total maximum amount of distortion. This includes TIM distortion (Transient intermodulation) as well as IM-distortion (intermodulation-distortion). TIM distortion occurs in connection with high-speed percussion sounds, such as the sound of dishes on drums. If the amplifier's share of this distortion is high, the amplifier will not be able to play the sound clean, but the sound will be distorted.

The higher the frequencies the amplifier is capable of playing, the less is TIM distortion. If the amplifier would be able to repeat 600 kHz, distortion would not occur at all. IM distortion means that the amplifier generates excess denominated, the so-called undesirable ghost signals. For example, fed in to 19 kHz. And 20 kHz, consists of the difference between 1kHz. Safety Because this amplifier has AC parts, its construction is permitted only in the technical work of teachers. Even in this case, the device should be checked by experts before connecting it to the network. Although the equipment has been revised, it is worth remembering that even the only speaker outputs may at best affect almost 70V the effective voltage.

Therefore, caution is necessary during building and operation. For instance, the speaker terminals should be protected against contact. Building instructions and testing of the amplifier circuit board components will be worth and an amplifier solder test in three stages: 1) The components of the power side, and all the cables signal cables except installed 2) any other circuit board components plus not only hybrid circuit STK 4231 3) STK 4231 placed and cooled, and the input signals the wires connected.

Installation of the power-side components and testing should be done carefully. The transformer wires insulation must first be removed carefully or checked that this has already been done. Then the transformer conductors order is checked on the transformer side.

The circuit board parts include STK4231II Hybrid, Led green, resistors of different values, ceramic and plastic capacitors, a rectifier, fuse holders and fuses, a coil, line voltage parts, potentiometer, RCA connectors, speaker output screws, and a cooling unit.This amplifier is so high quality that it would be understatement to speak HIFI amplifier. HIFI-confirmed-Finland the frequency response must be direct and distortion <1% 20-20 kHz. Our articles power amplifier circuit again meets the above requirements for bandwidth 5Hz -. 500 kHz, however, The frequency band is limited such that interference PREVENT birth.   The amplifier meets the requirements referenssivahvistimelle, which is suitable for measurement and comparison operation. Small 12-24V voltage system amplifiers operating in the power and properties of the are somewhat modest, eg.

a decent speakers testing. The amplifier is also suitable for demanding PA use

When the music occurs in shallow close 20Hz sound levels, may the whole amplifier power reserve may need to temporarily use. This happens especially when the low-frequency emphasis equalizer or amplifier used, for example TV. Looking at the context of the movie, with lots of sound effects. If the power is not enough that effect. situation, sound speakers is distorted, reducing the enjoyment of hearing or even a roach speaker drivers.

Distortion of human hearing range is only about 20 Hz-20 kHz.

S. The hi-fi speaker gamut extends its best 25kHz cent and bats hearing area "remains" 150 kHz, so what are the benefits amplifier superior frequency characteristics can be practically? The title 220W blue-mentioned power less than 1% distortion means the so-called. The total maximum amount of distortion. Em. crack includes mm. TIM distortion (Transient intermodulationsärö) as well as IM-distortion (intermodulation-distortion).

TIM distortion occurs in so-called high speed. in connection with the percussion sounds. These include. Dish sound on drums. If the question. crack share of the amplifier is high, the amplifier will not be able to play cue sound clean, but the sound is distorted.

What higher frequencies the amplifier is capable of playing, the less is TIM distortion. If the amplifier would be able to repeat 600 kHz, does not effect distortion occur at all.. IM distortion means that the amplifier generated excess denominated l. the so-called undesirable. the ghost signals. For example, fed in to 19 kHz. And 20 kHz, consists of the difference between 1kHz: s. Safety Because this amplifier has an AC parts is construction of schools permitted only in the technical work Teachers.

Even in this case the device should be checked by experts before connecting it to the network. Although the equipment has been revised, it is worth remembering that even the only speaker outputs may at best affect almost 70V the effective voltage.

The reason is, therefore, caution, as-built and the operational phase. Therefore, eg. The speaker terminals should be protected against contact. Building instructions and testing of the amplifier circuit board components will be worth and an amplifier solder test in three stages: 1) The components of the power side, and all the cables signal cables except installed 2) any other circuit board components plus not only hybrid circuit STK 4231 3) STK 4231 placed and cooled, and the input signals the wires connected.

1) Installing the power-side components and testing Carefully revised and juoteaktiivisella protective finish protected are soldered to the circuit board fuse holders, Diode bridges, LEDs, and the 4,7k ohm / 2W of series resistors and 10 000 uF's electrolytic capacitors. If desired, can the other LEDs or to install molemmatkin end of the conductors, wherein the second of them - unless both - can be installed later, the front panel indicator on the device.

The transformer wires emalieristys must first remove carefully or to check carefully that this has already been done.

Then the transformer conductors order is checked transformer on the side. STK 4231II-amplifier parts list:

The circuit board parts thereof:

STK4231II Hybrid 1 piece Led green 2 pcs 56kΩ ¼ W 2 pc 10kΩ ¼ W 2 pc 1.0kΩ ¼ W 2 pc 100Ω ½ W 2 pc 4,7kΩ ½ W 4 pieces 1kΩ ½ W 2 pc 560Ω ¼ W 2 pc 4,7Ω ½ W 4 pieces 10kΩ 2W 2 pcs 470pF ceramic 63V 2 pcs 100nF 100V plastic 4 pieces 470nF 100V plastic 2 pcs 10uF / 63V 2 pcs 22uF / 100V 1 pc 47uF / 100V 2 pcs 100uF / 63V 2 pcs 100uF / 100V 1 pc 10000uF / 100V 2 pcs SB256 rectifier 25A 600V 2 pcs The fuse holder 5 * 20 mm 2 pcs 10A Fuse 5 * 20 mm 2 pcs 3μH coil * 2 pieces * (Rpm 1 20 mm winding wire, air core diameter 8mm) Line voltage parts Grounded kojeverkkoliitin (10A) 1 Fuse holder 5x20 (10A / 250VAC) 1 Fuse 4AT 5x20mm 1 piece The switch 10A / 250VAC 1 piece  - Duration of the points 10A power also, and Network Connectors, hives the switch, due to transformer inrush current peak, otherwise, melt! Transformer 2x38V / 545VA 1 piece Signal Input Potentiometer 50 klog 2 pcs  - Or stereopotentiometri RCA connectors 2 pcs Speaker Output Napa Screws (2xpunainen / 2xmusta) 4 pcs Fuse holder 5x20mm (6.3a) 2 pcs Fuse 5AT 5x20mm 2 pcs The terminal circuit cooling: The cooling 0.25 - 0.35 ° C / W

🔗 External reference