MUZISHARE X7 KT88 Push-Pull Tube Amplifier Balanced GZ34 Light with Turntable And Remote Control for Hi-Fi Audio System

Technical parameters

Rated output power: 25W +25W (working status of RMS triode)

45W +45W(RMS superlinear working state)

Harmonic distortion: 1%(1kHz) frequency response of the whole machine: 15Hz ~ 30kHz(-1.5dB)

Input sensitivity: 280mV; 520MV (pre in)

Input impedance: 100 Kohm output impedance: 4ko8Ω signal-to-noise ratio: about 92dB output balance:<0.5db

Weight: 25kg power consumption: 260W

Use vacuum tube: 12AX7 × 1,12AU7 × 2,KT88 × 4,5AR4 × 1

Overall Volume (W × D × H): 410mm x 335mm x 198mm

Power supply voltage: ~ 110V/220V ± 5%(50Hz)

Working conditions: Temperature: 0℃ ~ 40℃ humidity: 20% ~ 80%

Storage Conditions: Temperature:-20 ℃ ~ 70 ℃ humidity: 20% ~ 90%

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X7

Meichic X7 double high-pressure tank rectifier pure tube amplifier/with pure rear stage/phono/balance

Noble, elegant, young, dynamic and powerful

Noble, beautiful voice makes you unable to raise interest in bargaining

Use imported Z11 iron core pole-level isolation cattle and imported EI iron core high-performance broadband output cattle; Use US 12AWG single and multi-strand gy-HDMI connection, pole-level isolation cattle effectively relieve current impact force, making low frequency leaping ability, the control force is enhanced, and the imaging force is richer. The machine adopts imported customized components.
5AR4 real gall rectification overload protection, balanced electronic tube life, rich gall flavor, Special Double high tension circuit design.

12AX7 high-gain front-stage tube is 100 times the gain coefficient of ordinary 6N3,6N8, etc. The sound is more vivid and fresh.

Four KT88 tubes are pushed at the rear level, with high pressure resistance, full and calm sound, strong momentum, delicate opening, extremely strong and powerful low frequency, and easy to cope with large food speakers such as symphonic sound.

Configure BISA current indication and external BIAS ADJ adjustment function to facilitate monitoring of power tube working status and adjustment; Dual-function level meter display, pointer swing with music, full of movement.

With MM pickup amplification, it is convenient for you to enjoy LP simulation original sound. It has the function of merging machine pure post-level random switching, full of power and water, and senior players have to play.

Headphone output directly has output cow output, and the quality of sound quality benefits from X7 output cow's unique core technology, which is beyond the reach of ordinary independent headphone amplifier.

If X5 is pregnant with EL34's unique round, young, analytical, meticulous and elegant;

X7 is a kind of KT88 output structure power amplifier valuable atmosphere, full, thick, open and strong;

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Looking at the picture is far more intuitive than the text description, but the feeling of X7 is still shocking. This shock not only comes from X7's huge body shape, expensive and exquisite modeling, but also the bright craft level of the body, the design and layout of panels like precision instruments also have paint technology comparable to millions of yuan of high-end cars, highlighting nobility. Specially customized dual-meter head multi-functional professional-grade output power meter and ammeter indicator head are usually applied to professional high-precision instrument, and soft orange backlight is revealed after startup, when working, the two hands waved with the music ups and downs, which was very dynamic and charming.

The X7 panel is orderly arranged with all kinds of Seiko-made switches and knobs, which are orderly; The two silver knobs on the right are high-gloss sand plating, which are volume adjustment and source input selection respectively, on the side are mute indicator light and remote control receiving window respectively; On the left side of the panel are power switch and working status selection gear, it includes the power selection gear of triode connection and ultra-linear connection switching and the selection gear of the combination/pure post-level function. Users can switch freely according to their listening preferences and the acoustic conditions of the environment to achieve outstanding listening effect.

The X7 high voltage link adopts LC π filter design, which consists of two secret choke coils with Nichicon provided by Japan electrolytic capacitor and current and inductance values of 350ma and 450mh respectively. The designer arranged a 5AR4 side-heating full-wave rectifier tank and two commutators for the high-voltage link of X7. This method is still rare in fever equipment, not only as simple as simple rectifier of type models, the circuit structure also needs to do a lot of work, which respectively supplies two levels of high voltage power, and the load margin of cattle also needs to be rich enough, this should be that the production cost of power supply cattle on KT88 models is relatively high at present. The sound performance can intuitively feel the X7 low-frequency force channel surging, even if it is difficult to push the closed box, it can be firmly controlled and forceful;

Audio transformer is the soul of a tube amplifier. The reason why maijingtu tube amplifier is unique is its unique multi-line and winding transformer technology; X7 audio transformer adopts the method of high and low magnetic leakage with up to ten layers of grouping and cross winding, imported EI silicon steel sheet with a variety of hybrid annealing technologies are all hand-made. This transformer has the advantages of good broadband response and extremely low distortion, and has the same working effect as maijingtu transformer. The primary inductance is as high as 210H(4.5 kph 50Hz), the primary leakage inductance is only 3.95mH, the distributed capacitance is as low as 100Pf, the frequency response is as high as 5Hz-150KHz(-3db), and the primary resonance frequency is as high as 240kHz; An excellent model, it often requires years of experience accumulation, material selection and materials, and after years of different equipment matching sound effects, it is finally established; The performance of sound transformation also depends on the designer's power supply cattle, many achievements in the selection of large components such as cattle ingredients can also be simply called "material science". The manufacturing technology of cattle is more important than the heart of the human body, the production technology of excellent cattle often achieves twice the result with half the effort in the requirement of sound effect; the selection of X7 power supply cattle adopts the current superior Japanese Z11 silicon steel sheet through professional annealing technology Ohno Continuous Casting (referred to as OCC single crystalline copper) through special process structure winding, the output cow is two Japanese EI iron core transformers with strong taste. It is made of mineral sea sand and resin and other special materials screened from the coast of Golden Beach in the South China Sea by high temperature fusion, which is composed of image binding force and density, the low frequency leaping ability is rich and natural, the details are extended, the audio frequency band is wide and loose, the sound performance is transparent, smooth and charming without dryness. Often this kind of complicated technical content cannot be appreciated by ordinary non-professional common sense users, so there are cheap tube amplifier super cheap, and expensive ones can be expensive to luxury.

The last-stage amplification output current of X7 is abundant. You can choose superlinear connection and triode connection, which provides players with more choices. When the matching sensitivity is high, when the box can be driven well without high power, the three-level connection method with smaller power output can obtain more delicate and sweet sound quality. However, for speakers that are difficult to push or have higher requirements on dynamics and sound field, the superlinear connection method can meet the demanding requirements. In the triode state, the sound performance is soft, delicate, clear and sweet; In the ultra-linear state, the sound performance is atmospheric, calm and full. The control of the listening feeling should be more regular, and the sound field is clear, strong and powerful.

X7 all the components in the machine are imported as always. The quality, stability and service life of the components are far different from some crude products on the market and counterfeit inferior similar products. Opening the base frame with multiple rows of ventilation and cooling holes, it is not difficult to find the setting methods of various parts, as well as the layout and treatment of connecting wires in different links, which are all well-thought-out and clever arrangements, and using the traditional point-to-point shed welding, even though the production time and cost will rise sharply, it can reduce the number of welding points, which can be described as Baileys without harm to improving the fidelity; the output stages of the pre-audio stage and the inverted phase stage respectively select a pair of 12AU7*2 and 12AX7*1 set for high fidelity replay earlier than the 1950 s for voltage amplification, KT88 * 4 of the final power amplification output, two push-pull AB1 output per channel, provides 25W * 2 output power in the three-level connection, however, it can output up to 45W * 2 under superlinear connection. In addition to the large Z11 transformer, the power supply also uses a choke filter with high inductance, and the noise ratio is as high as 92DB, while the previous stage uses a 5 AR4 vacuum tuber ectifier, which is more rare, the pre-stage input is amplified by the u value in 12AX7, and then is pushed by 12AU7 to form a complete pre-stage amplification circuit and push circuit structure. In the post-stage amplification part, there are also two independent rectifier circuits, plus two times of half-margin power output transformer, which endows X7 with strong driving force and high dynamic contrast.

X7, as always, adopts a more scientific, human, complex, and high-cost fixed bias, and takes care of the rigorous and precise attitude to science of fever; Automatic bias because the working point depends on the internal capacitance balance value, the aging of pipes and components is bound to cause sound deviation and cannot give full play to the correct value of the electron tube; However, fixed bias can make the equipment reach precise working point at all times through artificial mechanical adjustment according to the curve value of the electron tube itself, keep sound balanced. Users can directly switch V1,V2,V3 and V4 knobs on the chassis to observe the changes of ammeter pointer on the panel without using multimeter, and adjust at any time to ensure more accurate sound; switching and shifting V1V2V3V4 respectively correspond to the following four KT88 tubes V1V2V3V4, reflecting the current changes of each electron tube, for example: the V1 pipe needs to be adjusted to shift the gear to the V1 position, corresponding to the V1 electronic tube, and there are 4 BIAS ADJ on the chassis. Small hole, two left and right, V1V2V3V4 respectively. Use a screwdriver to gently twist the adjustable resistance in the hole and observe the pointer change on the panel. In the same way, adjust the current of 4 electron tubes to the same position to keep each tube working at the same working point, making the sound more accurate, simple, scientific and easy to use; X7 panel meter has the dual function of level display, in the working state, the switch and shift are switched to the METER gear. The response is the level change of each channel. The pointer swings with the music and is full of movement. This dual design is very human and easy to operate, it is not only a functional instrument but also a precision testing appliance to ensure that the machine is in normal working condition.

X7 has infrared remote control function, remote control uses solid pure aluminum, feels very comfortable, can adjust the volume size and mute selection; The volume system uses special Japanese original ALPS motor potentiometer, the whole volume attenuation process uses microprocessing to attenuate at 100 levels, and each level is processed separately with different numerical resistances, with an amazing accuracy of 0.7DB to ensure the accuracy and balance of sound at different volumes, which is beyond the reach of ordinary market components.

X7 adopts pure manual shed welding technology and adopts point-to-point full shed welding technology with high labor cost and high technological level. The shed copper branches adopt 6N copper branches, the junction point between the parts and copper branches is wound and tinned. The layout is reasonable and beautiful, and the welding is skilled. Friends who play tube amplifier know that it is authentic to build a shed at tube amplifier, which is often more beautiful than using circuit boards, regarding the basic differences between shed production and circuit board production, the following analysis paper review:

I don't know if enthusiasts have noticed it. Most of the world's high-priced audio equipment are known to use shed welding technology in publicity, especially the high-priced tube amplifier, almost all of them are using this time-consuming and laborious method, while the benefits of printing removing, which is widely used in circuit board., are mainly to further improve the sound quality of playback and make the routing between circuits more reasonable. Practice has proved that shed welding is indeed better in sound expression. Therefore, it is also the experimental object of amateur enthusiasts hands-on production School.
Traditional PCB welding is the mainstream in the electronic field due to its compact structure, beautiful appearance, relatively small volume and convenient mechanical welding. However, the printed circuit board uses a layer of copper cover on the insulation board as a conductive substance, and copper cover of the mass oxidation degree, N coefficient and its thickness have certain limits. In order to be beautiful and tidy, most manufacturers use computer row boards to design and draw. Their copper cover Guide diameter corners are sharp, and the thickness cannot be completely the same. The current is not smooth when flowing through these places, in addition, the resistance of the circuit board itself cannot be randomly selected like a shed, and the capacitance components between adjacent copper foil cannot be very low. Taking tube amplifier as an example, it is easy to produce ignition discharge on the circuit board at sharp corners and copper foil parts close to high voltage, causing problems. Due to the high internal resistance and power supply voltage of tube amplifier, the partial capacitance between the circuit board copper foil will also affect it, and damage the transparency of sound reproduction and other indicators. It is required that the gate drain resistance of the gate is connected to the input gate in the nearest way, and it is better to directly weld it to the pin of the gate, however, the resistance of the cathode also requires better grounding at the same point as the gate drain resistance, and also reduces the potential difference between them, which is difficult to do on the printed circuit board. However, the use of shed welding, but it can be easily realized. In fact, not only the tube amplifier, but also some disadvantages other than the above for the crystal machine, even for the crossover unit in the Speaker, The connecting line between speakers has a great influence. At present, frequency divider of most speakers are made of printed circuit boards. Although they are neat and beautiful, the influence of conductive copper foil also exists, because, frequency divider of the speaker often passes a large audio current, and the cross-sectional area of the circuit board copper foil cannot be too large, which will cause some power loss, even if you plus-sized the cross-sectional area to a certain extent, however, the quality of copper foil has not been heard of the high purity of 6N to N, which will leave a little regret in the hearts of enthusiasts more or less for the current concept of fever.

The so-called shed-type production is to use wires of different quality and thickness to directly jumper welding at each connection part, or directly stranding welding by the Lead Head of the component, with thick thread for large current and hairline rule for small current, due to the insulation layer spacing between the wires, there will be no short circuit naturally, but the technology of building a shed is relatively highly complex. Pay attention to the direction between the wires to avoid parallel arrangement that can generate coupling interference, reasonable arrangement of touchdown of the whole machine, the overall layout arrangement, the more intuitive and concise, the shorter the effect, the better, the reasonable design can reduce the resistance of the circuit to a lower level, making the current circulation more smooth and unimpeded, distributed capacitance can also be made very low in shed welding, which further reduces mutual interference and improves the sound quality. The high-tech ceiling welding is a beautiful lamp ac tube radio, almost without exception, made by ceiling welding technology. Now the popular Crystal Radio, recorder, compared with the sound quality and timbre, it is also beyond reach.
Because the production of shed welding depends on manual and a master hand, compared with printed circuit boards, their manufacturing speed is many times slower, and the cost and price increase will follow, it is also the expected result.
There is also a successful model of hybrid production, that is, the product of the combination of printed circuit board and shed type. The main body is designed and manufactured by printed circuit board, and the key parts are manually welded and recombined. In this way, it is also a smart way to reduce costs and improve efficiency without sacrificing the expression ability of sound quality. The famous audio brand Sonic Frontiers is one of them.

In terms of timbre, X7 has the obvious characteristics of gupa British sound. The high frequency part has a high transparency, rich details, excellent sense of space and instrumental music description ability. When listening to violin playing works, the sound lines of the piano are slim and flexible, the texture is real and full of gorgeous feeling, the chord rhythm is melodious, and the resonance of the wooden cavity is enough to make people aftertaste again and again; When replaying metal percussion, it can clearly show a clean luster, dynamic aftertaste, smooth extension and far extension, micro-dynamic not only has abundant energy, clear and accurate, but also has a special rich feeling of British voice in terms of medium frequency, both male voice and female voice can reflect the condensed and sincere texture. There is no overflowing tenderness, but it can give people a warm and natural enjoyment; As a pure tube amplifier with 45W output power, x7 can drive all big food speakers on the market, and can feel its abundant energy. Its dynamic impact is strong and powerful, the overall speed is moderate, and the control force is steady and calm. It specially replays the large dynamic drum, symphonic instrumental music, the low frequency is solid and deep, the texture is solid and elastic, and the transient burst is quite agile.

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Technical parameters

Rated output power: 25W +25W (working status of RMS triode)

45W +45W(RMS superlinear working state)

Harmonic distortion: 1%(1kHz) frequency response of the whole machine: 15Hz ~ 30kHz(-1.5dB)

Input sensitivity: 280mV; 520MV (pre in)

Input impedance: 100 Kohm output impedance: 4ko8Ω signal-to-noise ratio: about 92dB output balance:<0.5db

Weight: 25kg power consumption: 260W

Use vacuum tube: 12AX7 × 1,12AU7 × 2,KT88 × 4,5AR4 × 1

Overall Volume (W × D × H): 410mm x 335mm x 198mm

Power supply voltage: ~ 110V/220V ± 5%(50Hz)

Working conditions: Temperature: 0℃ ~ 40℃ humidity: 20% ~ 80%

Storage Conditions: Temperature:-20 ℃ ~ 70 ℃ humidity: 20% ~ 90%

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Features of this machine

1. Handmade, the whole machine adopts shed welding

2. Use two high quality broadband high sound quality Japanese EI-type output transformers

3. Use high-power Z11 iron core ring power transformer specially designed for this machine

4.5AR4 is used for rectification and power supply for voltage amplification and push level

5. Use 12AX7 and 12 AU7 vacuum tube for voltage amplification and phase inversion, use KT88 vacuum tube for AB1 type push-pull power amplification; Provide triode and superlinear selection function: triode working mode, soft sound, pure and smooth, suitable for enjoying music of human voice, strings and other types; Super-linear working mode, sound, unrestrained, good momentum, suitable for enjoying music of big scenes, big dynamics and other types.

6. Peripheral power tube current adjustment button and current display meter head

7. It has pure post-level function and can be connected with independent front-level signal input.

8, with phono function, can be connected to vinyl record player

9. It has a truly balanced input port, which is musical and has richer details.

10. Infrared function remote control

11. Startup mute delay function (about 30 seconds)

12. Use Japanese ALPS motor potentiometer

13. Convenient installation of plug type vacuum tube protective cover

Vacuum tube model for this machine	Replacement vacuum tube model
12AX7	12AX7EH,ECC83,E83CC,CV4004  ECC803,5751
12AU7	12AU7EH,ECC82,5814,6189,CV4003
KT88	KT88EH,6550EH,6550,6550A
5AR4	GZ34