The famous Hetian Maodan pre-stage circuit, 6N3+6N6 version, without power supply, Marantz 7 improved circuit. Spark 110 imitates Hetian Maoshi pre-stage circuit diagram, board code: JCDQ-27D
JCDQ27D Hetian Maodan pre-finished blank board without power supply (dual-panel): high-quality fever component assembly, small ripple and enough courage, it is a good match for the pre-amplifier, and the effect is excellent!
The exquisite FR4 double-sided glass fiber board has a thickness of 2mm and a size of 212×108mm. The amplified line is the classic Hetian Shigeru line, which is a completely improved Marantz 7 pre-stage. Dual monophonic symmetrical design.
210V high voltage DC power supply. 3.15V-0-3.15V two groups of independent filament AC power supply, can be equipped with two 6N3 and two 6N6. Although the four-tube filament uses AC power supply, due to the corresponding measures, the communication noise is very small and the electronic tube has more flavor.
This route inherits and develops the unlimited potential of Maran's seven styles. At a price of only one hundred yuan, it can play the current domestic electronic tube front-end with excellent materials and leading production concepts.
JCDQ27D finished board with 4 tubes
JCDQ27D finished board does not have 4 tubes
Affirmation: The 4 electronic tubes and individual components on the circuit board are second-hand disassembled products. The components on the finished board are different due to different assembly batches. The brand, model and parameters of some components will be slightly different. The parameters of the components assembled on the board shall prevail. !
The following is a schematic diagram, only one channel is drawn, for reference only.
This circuit is composed of two-stage pure class A amplification plus one-stage common-screen and common-cathode output mode. The first two stages of its circuit use 6N3 two-stage common-stage cathode amplification, and the output stage uses the SRPP method, but the difference of this SRPP method is that there is no that between the cathode of the upper tube and the anode of the lower tube. Cathode resistance. Different from general voltage amplification, the third-stage SRPP output stage does not have any voltage amplification effect. It is only used as a buffer stage to reduce the output impedance and increase the output current, but compared to the ordinary cathode follower, the drive load can be stronger. In the overall circuit, in order to improve the performance of music details and improve the electrical performance of this machine, this machine uses appropriate loop negative feedback to reduce the output impedance and the overall frequency response and distortion. It can have such excellent overall performance. I believe that its last-stage special SRPP cathode output circuit is the essence of the whole circuit. The dynamic and high-frequency response of this circuit is better than M-7, and its analysis power and signal-to-noise ratio are extremely high.
This circuit is a bit different from the original Hetian Maoshi circuit. The first stage has an additional 100V voltage regulator, which is mainly determined by the working voltage of 6N3, and an additional voltage regulator is added to ensure that the circuit is stable and reliable even when the voltage fluctuates. work.
The matching power board is introduced as follows:
JCDQ25 two-way high-voltage DC stabilized product board for tube amplifier: This line is used for the front-end circuit board imitating Hetian Maodan in this department. When the power is just turned on, the high voltage will slowly increase the voltage from 0V to avoid sudden changes in voltage from impacting the tube.
The assembly of high-quality fever components, the ripple is small and the taste is enough, it is a good match for the bile pre-amp, the bile amp, and the effect is excellent!
Exquisite FR4 fiberglass board, 208×117mm. Full line, dual mono channels are symmetrical, two high-voltage DC regulated output. Selection of high-quality tonic components assembly. Two 6Z4 rectifier tubes, two 6P1 adjustment tubes, two 6N2 sampling tubes, RCRC secondary filter. In terms of technology, the filament is powered by 4 groups of 6.3V independent AC power, and the left and right high voltages are independently regulated. Brands such as Nissan electrolysis, German EPCOS electrolysis, West German MKP film capacitors and other brands are used to form a powerful power supply circuit, and the wattage of the metal film resistance is left margin. High-quality terminal, high-quality silver-plated ceramic socket.
Board input AC voltage: 250V-0-250V two groups, 6.3V 0.6A two groups for two 6Z4 electron tubes. Two sets of 6.3V 1A are used for four filaments of 6N1 / 6P1 tubes. The effect will be better if the current is larger!
The output DC voltage is adjustable from 180 volts to 270 volts, and the maximum output current is more than 40 milliamperes. 220K (470K) potentiometer can change the voltage adjustment range.
JCDQ25 finished power supply board is not equipped with tube
JCDQ25 finished power supply board with electronic tube
Matching 120W high quality multi-purpose power transformer for LG120 tube amplifier: used in Hetian Maodan pre-stage line, suitable for most pre-amplifier use, you need to purchase separately, please contact the seller.
EI 86X45 iron core, Z11 iron chip thickness 0.35mm, fixed by British Red Bull clip, transformer core size: 88mmX75mmX75mm.
Input AC 0-220V-235V primary and secondary shielding ground
Output high voltage: 280V～0～280V 60mA, 280V～0～280V 60mA two groups of six lines
