Single tube 6N11 (6DJ8) dual-channel preamplifier: it can also be replaced with imported 6H23, 6DJ8, or even 6N1.
6N11's low internal resistance, high current and good linearity are generally not available in bi-triode tubes. The 6N11 has a large driving current and full driving force, which can be well matched with the transistor / tube power amplifier, and can create simple and beautiful audio equipment.
The power supply of this line is sophisticated, the tube filaments are soft-started and stabilized, and the high-voltage electronic filter soft-start power supply has a small ripple. It is different from the common in the arrangement of components and has unique features.
This pre-amplifier is simple and the power supply is complicated. This line requires no adjustment except for the filament. It is easy to make without adjustment. The sound background is quiet, the sound quality is transparent, the high frequency is elegant, the high and low frequencies are more balanced, the air is full, and the dynamic good vocal performance is excellent. Although a tube is used, it is also nicer than most tube amplification boards on the market. The effect does not lose most of the one or two tube preamps in the market.
Exquisite FR4 double-sided high-quality PCB board, two-channel design, size 168mm × 100mm, board thickness 2mm, double-sided characters can be installed on both sides of the resistance component, the tube can be exposed assembly.
Assembly of high-quality resistance-capacitance components, transistor rectification, 6H6P tube buffer output, 4-level filtering. German Visa MKT capacitive coupling, silver-plated ceramic tube seat, one domestic 6H6P, one domestic 6N11. Two LT1086 three-terminal voltage regulators provide 6H6P and 6N11 wire voltage, and soft start power supply. All ground wires are grounded at one point, the line is quiet, and it can work when connected to a transformer.
Compared with the choke coil, the electronic filter has many advantages: small size, light weight, low cost, good performance, and the immediate effect will surprise you. This board also has an important function, which has a high-voltage delay effect. The voltage ranges from 0V to 135V for a few seconds. Using a voltmeter, you can see that the needle has a slow rise process, which is a big shock to the protection of the electron tube and the line. There are benefits.
From the sound of replay, the sound of high voltage using regulated power supply will appear a little "tight", while the sound of not using regulated power supply is relaxed.
Working voltage; DC high voltage 132V, filament 6.3V, tube working current 4.5mA × 2, gain about 23 times.
We have debugged the circuit for this machine, made a reasonable configuration with high-quality components, selected a suitable working point, and accurately matched key components to ensure that the circuit works in the best state.
High-precision 24 gear 100K stereo volume potentiometer Liangyin dual-connected voltage-dividing stepping type, high-precision, non-inductive, low noise metal oxide film SMD chip resistance welding, the error between the two channels is less than 1%. The performance and accuracy and the use effect are far superior to the carbon membrane potentiometer.
The use of carbon film volume potentiometers is one of the main phonemes of sound quality deterioration. Only those who have used resistance welding stepped volume potentiometers know the improvement effect. Some people spend a lot of silver on tonic capacitors, resistors, wires, and connectors. The only potentiometer is carbon film. Whether it is ALPS blue shell Nissan potentiometer or a few hundred yuan Nissan NOBLE noble potentiometer, after all Carbon film.
Oxygen-free copper plated American CMC gold plated RCA socket. The internal wiring adopts the imported internal signal line. The imported and exported lines use imported German LEONI high-purity copper wire. The wire is soft and the purity is 5N-6N, which is equivalent to the level of single crystal copper, and the sound is mellow and neutral. The layout is reasonable, the line is quiet, and the effect is excellent. It is suitable for enthusiasts to give it a try!
AC power supply: 220V50HZ (customizable 110V60HZ)
Input socket standard: RCA socket (2 groups input selection, 1 group output)
Magnification: 23 times
Dimensions: 253mm long, 152mm wide and 65mm thick (excluding knobs and terminals). The cabinet is composed of a frame and upper and lower covers. It is made of 2mm thick cold-rolled iron plate, with high precision of die opening size, gray matt paint on the surface, and aluminum alloy legs.
Weight: Net weight 2.9 kg (3.5 kg with packaging)
The reason for the non-linear distortion of the carbon film potentiometer -------- The carbon in the ordinary carbon film potentiometer is a non-metallic semiconductor element, which is located in the IVA group of the second period of the periodic table. The chemical symbol is C, its atomic number is 6, the electronic configuration is [He] 2s22p2, carbon is a semiconductor, and the carbon film potentiometer is made by coating a layer of carbon film on a horseshoe-shaped paper rubber plate. The carbon film body is formed by coating carbon black, graphite, quartz and other materials on the surface of the substrate. The rivets are used to fix the copper (or iron feet) as the lead-out solder legs. The carbon film plate and the copper feet are two types of conductor materials , PN junction is formed between them. The PN junction is also formed between the sliding copper brush in the potentiometer and the carbon membrane plate. The principle of the PN junction type diode. Overcurrent will produce nonlinear distortion and affect the sound quality. All copper contacts, there is no problem of nonlinear distortion, and the fidelity of sound quality is greatly improved. Therefore, the reason why the high-end premium audio does not use carbon film potentiometers, but the stepping switch volume potentiometers
