rear amp tube 2SA1943 2SC5200 output
mono amplifier board adjustable A
discrete tube rear amplifier
DIY Kit ( need buyer weld)
Technical parameters:
Output power: 70W / 4 ohm load; (Total harmonic distortion THD + N <0.5%), DC +-40V, 4 ohm load measured.
Speaker Impedance: Available 4-8 ohms.
PCB size: 80 * 50MM.
Power supply: DC Dual 18-50V transformer 200 watts or more, the need to replace withstand higher voltages higher capacitance.
Discrete Tube: 2SA1943 2SC5200, classics on the tube(Actual delivery of boards).
Introduction:
DX-AMP HIFI forum in line a few years ago there is fire, derived from the foreign forum a hair called Destroyer XShaoyou design, so habitual everyone says DX AMP amplifier, only to discover later, this line is on the Y amaha
RX-V690&39;s rear stage amplifier circuit slightly modified from, no wonder the sound will be better, this line features:
1) Good quality sound, high sound resolution, discrete power amplifier can also be the most difficult to do the treble doing very good, very Qian
Fine-sounding bass valuable is also dive deep feeling;
2) Basically does not transfer tube, no pairing, low requirements for components, whether imported or domestically capacitor capacitance or supplements
Sound performance basically no difference, are very nice (for long-term reliability, shop or choose a capacitor imports)
3) Introduction of the itinerary, simple debugging will basically be able to complete the welding friend.
Parts DIY Commissioning notes :
1) After completion of welding heat sink installed (note tubes and fins to be well insulated), adjust VR2 (1K precision adjustable
Resistance) makes the quiescent current 50MA around, VR2 clockwise quiescent current becomes smaller, counterclockwise is increased
Namely: the output voltage across the OUT point A about 5MV (R24 output voltage across the resistor 0.1 ohm resistor value is divided by this static
Current), A point is a test hole, PCB marked above, on the output side
2) the midpoint zero, adjust VR1 (5K close adjustable resistance), so that the output (OUT) to ground (ie, across the terminals of the amplifier output)
Zero mV; generally within ten millivolts are OK.
DIY KIT Link:
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:
You can choose to buy the power supply filter board with speaker protection,click the picture
List of components, including all components of the board
PCBboard silkscreen with component values are very convenient DIY
Black 3Pin is AC power input terminals: +V GND -V select Dual 18-50V DC voltage.
recommended dual 35V DC
Higher voltage, then we would replace the high capacitance voltage value
Green 2Pin 5.04MM is mono input terminals: IN GND , Audio input connection
Black 2P 8.25MM terminal is Audio output : GND OUT
Amplifier board size, very suitable for the machine, the sound quality is also very Ok, well-known machine circuit
DX AMP circuit is performance and sound is good, with 0 noise when you close the VOL
Board needs to work with a heatsink,
Heatsink and IC do insulated enclosure
oh, please remember that the link does not include the heat sink
The Installation image for reference
Circuit design for reference
Friends interested in the reference circuit for learning and communication