MUSIC--300B Power Amplifier

In recent years, a few new and competitive domestic manufacturers of power amplifiers have emerged. Zhejiang Jiaxing Music Space Time Power Amplifier Manufacturing Co., Ltd. is one of them. The company consists of a group of professionals who love music and stereos and are engaged in research, development, production as well as sale of electronic tube advanced stereos. Music Space Time is adopted as the company brand. Due to many years¡¯ experience in audio business, it has access to all kinds of domestic and foreign classic electronic tube amplifiers and thus developed MUSIC Collection Hi-Fi amplifiers after elaborate research and learning. Most types are integrated power amplifiers and there are also front-and-back split type of power amplifier and earphone amplifier. Famous tubes such as EL-34, KT88 and 300B have their own corresponding machines.

MUSIC-300B electronic tube amplifier is a new launch of Music Space Time. Pentode 6J4P acts as the output and voltage amplification of the first stage and can provide sufficient excitation voltage for back stage circuit. Triode 6N6 is in direct coupling with the first stage. The output circuit of cathode works as the pushing stage, which can achieve good impedance matching with end stage, little non-linear distortion and sufficient driving force. Here, common practice of parallel connection is not applied to the two triodes, so the timbre and analysis ability are in an ideal effect. Directly heated power triode 300B-98 is adopted as the power output of end stage and its dynamic will be not restricted due to rated bias voltage. Filaments in the left and right soundtracks are with independent direct current supply so as to avoid inter-disturbance. In addition, little large loop negative feedback is imposed on the whole amplified circuit of MUSIC-300B in order to reduce transient distortion as much as possible.

As to its appearance, MUSIC-300B has a smaller size than other types in this audition. Normal layout is applied in its whole structure. The bottom plate is made of steel with silver grey baking painted surface. The black aluminum alloy panel is treated with blast surface with tiny and even grain, and matching dark golden chrome-plating volume and input selection buttons, which looks quite elegant.

Above the bottom plate, there are eight electronic tubes arranged in order. The surface of three square screen boxes is decorated with glistening ice baking paint, in which the power transformer and output transformer are installed. Low frequency chokes are installed in one black round screen box. At the first use of the machine, each electronic tube should be put into corresponding seat in accordance with the number, but the seat numbers are written with hand, which seems not to be formal. On the back plate, MUSIC-300B provides three sets of line signal input ends, which are enough for usage of fans.

Inside the bottom plate, rather high level of producing craft is shown. All the components are installed on one large printing circuit plate and connection lines between the circuit plate and transformer, volume potentiometer, input buttons as well as wiring terminal are put in order.
Components adopted in MUSIC-300B are of high grade, such as imported metal-film resistance, German WIMAMKP specialized audio capacitor, PHILTPS electrolytic capacitor, as well as power switch and potentiometer from Japan. Audio output transformer adopts imported Z10 specialized audio steel sheet and the non-oxygen copper insulated wire is reeled carefully by the technician. The frequency response can reach 10HZ-100KHZ.

After audition, MUSIC-300B is characterized by thick, warm, soft, saturated and natural sound, especially when vocal discs are played. Mouth shape and location of both male and female singers are quite accurate and even reach a surprising level. Vocal sounds played in MUSIC-300B seem to be pleasant, relaxed, smooth, fruity, natural and with delicate and rich rhyme and residual sound just like live singing. But if some other power amplifiers are used to push, the sound will be tight, stiff and without live sense. So it is no doubt that MUSIC-300B is good at playing vocal sounds and that is the most attracting feature of it. When large-scale symphony disc is played, the sound seems to be especially saturated and warm. If string music is played, you will easily feel the powerful quality of music. The friction sound of strings is true and detailed. It is interesting that whatever for string, percussion or orchestral music, MUSIC-300B can present a noble audio sense with reverberation and ambience in the music hall.

As same as playing vocal sound, the location of each section in the symphony is also quite accurate with no obvious flattening tendency. As to the speed and transparency, the performance of MUSIC-300B is mediocre due to its back sound stage, dim timbre and ordinary speed. Perhaps for its limited 9W+9W output power, you will not hear strong and violent rhythm and striking force in low frequency driving force, instead, you will get thick low frequency energy, whose musical performance is in harmony with high frequency. Obviously, people will not use 300B on purpose to present dynamics and force but pay more attention to its musical taste. If a pair of excellent speaker boxes are matched with, MUSIC-300B is worthy of recommendation indeed.

Basic Specifications
Output Power£º9W+9W
Frequency Response£º12HZ-38KHZ
Signal to Clutter Ratio£º78dB
Non-linear Distortion£º1%
Input Sensitivity£º350mV
Input Impedance£º100K¦¸
Price for Reference£ºRMB 5, 500

Extracted from¡¶Audio & Video Technology¡·¨C111 Analysis of 8 domestic power amplifiers editing department of Audio & Video Technology