Description

Product features and technical parameters:

Circuit: Using the improved principle circuit of the original version of Hetian; excellent PCB circuit design, reasonable, regular and symmetrical device layout, and strictly follow the single-point grounding wiring.

Chassis: It is a special chassis specially made for the Hetian pre-class, and the knobs are all-aluminum solid-core sandblasted and oxidized high-grade knobs. The whole box is made of aluminum, the thickness of the body is 2.8mm, and the thickness of the panel is 8mm; it is finished by a high-precision milling machine, the tube seat is positioned accurately, the opening is regular and smooth; Shiny and tasteful.

Transformer: The horizontal transformer with side cover with power 120W (EI8642/H50) is used, the primary and secondary windings of the transformer are strictly shielded, and the advanced vacuum method at home and abroad is used to impregnate the paint, and the impregnation paint is transparent and tight. The appearance is bright black, classic; the power is super enough. The power filament/left/right channel filaments are powered by independent windings, which completely eliminates crosstalk between each other, and the transformer makes a good sound.

Electron tube: JJ Ecc83*2pcs /JJ Ecc82*2pcs /Shuangguang J-level 6Z4*2pcs.

Potentiometer: Japan ALPS original 16-type potentiometer

SPECIFICATIONS

1. Input sensitivity: 200mv

2. Voltage output: 2V (RMS THD<0.03%)

3. Signal-to-noise ratio (S/N Ratio): 98DB

4. Frequency Response: 10Hz-50KHz (-0.5DB)

5. Input voltage (AC Input): 220V/110V

6. Power Consumption: 50W

7. Dimension: 360MM*190MM*140MM (depth-width-height)

8. Net Weight: 4.5KG

The electronic tube pre-stage is a tone processing amplifier used between the sound source and the power amplifier; the pre-stage produces sound, and the rear-stage produces output, indicating that a good pre-stage plays a key role in the entire audio amplification system; therefore, for the front stage The choice of level is also critical.

The electronic tube preamp, with the special "bile taste" of the bile duct, has won her reputation and praise among all preamps in terms of listening sense, and has always ranked first, and her reputation has been prosperous for a long time.

Among the pre-stages, there are two well-known pre-stages: Shigeru Wada and Maran-7, which have wandered between them several times. Through repeated proofing and comparison, it is found that in terms of performance and sound quality, Shigeru Wada is extremely outstanding. It not only maintains the mellow and musical characteristics of Marantz7, but at the same time, it is better than Marantz7 in terms of dynamics, transients, high and low frequency response, and analytical power signal-to-noise ratio. In fact, it is not difficult to find only from the analysis of Hetian Shigeru's circuit. Its pre-stage is a two-stage voltage amplifier composed of a high-gain double three-stage tube with very good stability. Only this tube can Amplify the signal to about 10 times, it has high sensitivity; the latter stage is also an emitter-level follower composed of double triode 12AU7, which is familiar to everyone and has excellent performance. The purpose of this stage is not to amplify the voltage. , but it has a very good amplifying effect on the current. The pre-stage designed in this way is very reasonable. It has a very high sensitivity and a very good load capacity at the same time. No matter what kind of post-stage is used, it is more than flexible. , to the fullest.

The machine is equipped with meter signal amplitude adjustment at the front and bottom feet (all have been debugged before leaving the factory, do not adjust at will)

Anyone who is familiar with HShigeru Wada preamps knows that it is characterized by prominent vocals and good alto. This is suitable for the even-order harmonic distortion generated when the tube is working. The even-order harmonic distortion will not reduce the sense of hearing. On the contrary, it will increase the beauty of the sound, which can make the sound more moist and some details will be more prominent. The details have been optimized to a certain extent, especially when playing vocals, there will be some emotional flavors, and the gall flavor is very strong. It will not only give charm to playing vocals, but also have a unique style when playing some small pieces of music, such as some indoor recordings of violin, saxophone, jazz, etc.

The audio input behind the machine has been upgraded from the original 1-way input to 2-way input, and a push-button input switch is added in front of the control panel, which is more convenient to use and operate.

     The rectifier circuit is equipped with a switching circuit that replaces the domestic tube 6Z4 and the imported tube 6X4, which can be easily adjusted on the casing surface of the finished machine. Domestic tubes and imported tubes can be replaced at will, eliminating the need to spend a lot of money to purchase a conversion seat before replacing imported tubes.

The circuit is redesigned for the LAY board, and the power supply and signal are completely isolated, which further reduces the noise floor. The circuit parameters have been fine-tuned, and the sound is more delicate and soft.

The holes of each tube on the upper cover of the machine are marked with the type of tube used at home and abroad by laser, and the installation/replacement is clear at a glance

The electronic tube part of the whole machine is customized and added with an electronic tube protective cover, and the protective cover adopts a plug-type installation, which is more convenient to disassemble and assemble. Protection and heat dissipation are the best of both worlds.