This link is two channels made of 2.0
PCB board only : no components
Technical parameters:
Output power: AB Class is 300W / 4 ohm load; A Class is 100W/4 ohm load (Total harmonic distortion THD + N <0.3%)
Speaker Impedance: Available 4-8 ohms.
PCB size: 59 * 236 * 1.6 MM.
Power supply: DC Dual 18-50V transformer 300 watts or more, the need to replace withstand higher voltages higher capacitance.
Discrete Tube: 2SA1943 2SC5200 OR NJW0302 NJW0281, classics on the tube(Actual delivery of boards).
The default is 2SC5200 2SA1943, you can leave a message to change of NJW0281 NJW0302, the same price
About E405:
accuphase E405 is an upgraded version of the E305, E305 belong to infrastructure diamond diamond FET FET dual differential input
Has a very low crossover distortion, unlike E405 E305 is pure DC, the entire line is not a coupling capacitor, nor
Feedback capacitor, is a current negative feedback type, with excellent dynamic response and dive depth, this line reference golden voice E405
Pure stage, with DC servo circuit (served by a very low noise OP07), Omron relay + C1237 seat speaker protection
Speakers for your escort; increase output overload current protection there.
E405 sound characteristics: natural slim, sound broad, large dynamic effect is very good, the biggest feature is the bass dive deep.
FET diamond diamond do double differential input, effectively suppress crossover distortion, pure DC architecture enables dynamic response is very good, the DC servo ensure the midpoint is almost zero, the actual 1MV up and down, very deep bass dive
Description:
1 There are 1% precision resistors metal film resistors (apart from 1W to 5W 5% accuracy and no external sense resistor), the use of CBB capacitor P hilips Cbb capacitors, mica capacitors.
2 electrolytic capacitors have a Black Edition, there ELNA and Nichicon, Rubycon and other famous capacitance. To ensure the stability of the circuit, and noise removal clean.
3 Select the audio coupling capacitor 1uF Weimaraner capacitors imported from Germany, to ensure that each channel to ensure that the small signal clean and clear sound.
2SC5171, 2SC1930 T oshiba bipolar transistors, the role is to promote the tube.
A970, C2240 T oshiba is a low noise, high power audio transistors dedicated amplification.
2SK246, 2SJ103 T oshiba good quality foundation dedicated sound field of high-power differential line pipe.
2SD669 H itachi imported NPN silicon tube, 2SD669 is working in a single-ended Class A status, the positive and negative half-wave signal alone by 2SD669 completed, so there is no crossover distortion, but also rich in even harmonics, timbre there are some moist role, and thus enlarged board very resistant, while 2SD669 is working in a big 50mA current status (normal op amp, amplification integrated only a few milliamps), to deal with large dynamic music signals easy to get the most realistic sound performance Play limit the effect .
Technical Parameters:
Output power: 300W (4Ω) Mono class AB CPI 100W, (8Ω) 150W Mono Class A 100W class AB
Frequency Response: 20Hz ~ 20kHz3Hz ~ 150kHz (1W output)
Total harmonic distortion: 0.05% (20Hz ~ 20kHz)
Damping: 180 (8Ω, 50Hz)
SNR: 110dB (RCA inputs)
93dB (balanced input)
123dB (input stage)
Gain: 128dB (after stage amplifier section)
Parts DIY Commissioning notes :
Debugging steps:
1: welded correctly installed the heat sink (Note to check the insulation between the bassoon and fins); first adjustment differential input stage current 2MA: regulator VR1 (500R) Adjustable
Resistance so that C, D two voltage 2V (ie R9 (1K) voltage across the resistor); when the input differential current 2MA, this value is the best sound quality. C, D points
The board is marked with; the picture below marked with debugging method
2: bassoon quiescent current of 100MA: adjusting the adjustable resistor VR2 (1K) such that A and B two voltage 22MV, where the quiescent current I = 22MV / 0.22R resistance
That is 100MA; if the customer fin is large enough so as to increase the quiescent current, general 100MA-300MA sound best.
Product pictures:
Note that this amplifier power is rectified and filtered DC power supply after a double, not directly connected to the transformer oh
Recommend shop rectified and filtered with a trumpet-protected power strip:
List of components, including all components of the board
PCB on the back of a large current place
are tin-plated to ensure adequate flow of large current
PCB board are marked with the value of each original,
DIY is very convenient.
Friends interested in the reference circuit for learning and communication