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HIFIDIY mini-A power amplifier A20 kit


Notice : This products is kit, you shoudl assembly it by yourself , the whole kit is about 13KG with the package

What is A power amplifier, in fact, a very simple answer to this question, we can look Baidu or Google, we will cite BAIDU Details:

A power amplifier (A class amplifier) output stage two (or two) transistor is always in a conductive state, ie regardless of whether they are to maintain transmission signal input current, making these two currents is equal to the peak alternating current, which the maximum signal when the AC load flow cases. When no signal, the two transistors of the same amount of current flow, so there is no central point of imbalance in the output current or voltage, hence there is no current input speaker. When the signal tends to positive, the line at the top of the output transistors allow the inflow of more current, the bottom of the output transistors are relatively less current, due to current imbalance in the beginning, so into the speaker and to promote sound speakers. A PA works with the best linear, each output transistor full-wave signals are larger and completely ignore the existence of crossover distortion (SwitchingDistortion), even without application of negative feedback, it is an open-loop distortion is still very low, so known as the voice of the ideal amplification circuit design. However, both advantages and disadvantages of this design, A class amplifier put the biggest drawback is inefficient, because there was no signal there is still over-current flows, power to convert the entire high-calorie
A power amplifier is ideal for playback of music, it can provide a very smooth sound quality, warm and mellow tone, treble and transparent open-yang, these advantages sufficient to compensate for its shortcomings. A power amplifier heat shocking, in order to effectively deal with heat problems, the CPI amplifier must be large radiator. Because of its low efficiency, a power supply must be able to provide sufficient current. CPI a 25W amplifier power supply capacity of at least 100 watts enough for class AB amplifier used. Therefore, the size and weight of the CPI machine than Class-AB Large

These are the BAIDU of information on, we should also have a general understanding!

As DIYER for the production of PA, the production of A amplifier can be considered a kind of ultimate test, as to Beijing to "less than the Great Wall of non-hero", this is the level of a DIY amplifier stage and symbolic!

The amplifier special features:
1) The modular frame design, easy to use a different amplifier board
2) The main amplifier circuit reference KRELL KSA50 lines, we have according to the actual needs of the line to modify!
3) Core board sampled the United States DALE military regulations RN55 series resistors, high power output resistance for the non-sense type, nichicon KG, and KZ series of high-quality capacitors used - HIFIDIY this design to maintain consistency in large quantities!
4) Core 3 tubes using audio-specific transistor 2.24097 million, medium-power tube used ON high quality tube MJE15031, MJE15030, the output tubes used ON MJL3281, MJL1302 --- HIFIDIY matching test to send!
5) Use of day l A-silicon 416W transformer, the actual test indicators are very good!
6) The chassis and the chassis with the CDM12 turntable manufacturers to ensure good quality!
7) before and after the modular design of the first-level modules before and after the class using our specially designed AD797 preamp, sound, neutral, dynamic big!

We design at the sound of this amplifier A state evaluation of the original language: "a special sweet and delicate. Alto thick, low-frequency particularly fierce... High-frequency sweet" ---- specified, with the entire system as a whole is very important, different sources, and Different speakers will produce different results! we have a design evaluation with a one-sided, because it is DIY production, we can according to their own love for tuning!
At the same time the package temperature as the ambient temperature changes in the hot days and the winter will be inconsistent!

This package contains
1) The amplifier chassis set that contains all the connectors!
2) core amplifier board two, three tubes for providing matching
3) core power supply board 1 is equipped with nichicon KG25V22000UF
4) 416WA-level transformer
5) AD797 * 2 expansion flow of a pre-level panel kits

The size is  : 250*130*320(MM)  .

 Technical information :

 Input : 110V-220V input

Input   Impedance :  47K

Output Impedance:  8 ohm

Output Power:   A chass 20W

Frequency range: 20HZ-20KHZ 

Suite Photos:

All circuit board packages:


ON Series Power Transistor

NICHICION the highest level of audio-specific use of KZ and KG


Motherboard with a full range of DALE resistors

Sunrise Custom 416W Class A transformer!


High-quality power amplifier output terminal and Taiwan, the use of RCA




AP test amplifier frequency response curve:


The assembly instructions please check this link:

Add to Cart:

  • Shipping Weight: 13lbs
  • 11 Units in Stock

This product was added to our catalog on Tuesday 22 December, 2009.