Outdoor Front Service LED Display
Front Service Outdoor Fixed Install LED Display Screen
1. High refresh rate: With NOVA STAR control system, no scanning line when photographed
* Nova MSD 300 sending card and Nova mrv328 receiving card
* Cabinet size:960x960mm
* Kinglight/Nationstar LED Lamp, Refresh rate:1920-3840hz
* Ultra-Light designing, less than 30kg/pcs
* High brightness up to 6500cd/sq.m, even in the sunlight conditions can see clear, but low power consumption to save the electric power cost.
* High debugging brightness and no damage to gray scale, achieving the debugging technology for nice image.
* Passed the TÃœV,FCC,ROHS,CE cetification.
Outdoor Front Service LED Display,P3.91 Outdoor Led Screen,Led Stage Screen Guangzhou Chengwen Photoelectric Technology co.,ltd , https://www.cwleddisplay.com
2. High gray level: 256 RGB each ,display 16.7M colors ,vivid and perfect video effect
3.High resolution: The most apparent features of the new generation of LED display
4.Good color uniformity
5. High Brightness: 6000-8000 cd/m2 ,brightness automatically adjusted
6. High Quality: CE, RoHs, FCC, UL, IP65, ISO9001 passed + 96 Hours serious testing time
7. Long life span: over100,000hours, warranty from 2 years.
Designing a Tube Preamplifier: Key Considerations
When designing a tube preamplifier that meets Hi-Fi standards, it's important to understand that vacuum tubes offer unique advantages such as high input impedance, high operating voltages, and relative ease of maintenance. However, creating a tube preamp with exceptional audio quality is more challenging than building a solid-state preamp. Below are some critical points to consider during the design process:
1. Selection of Electronic Tubes: There is a wide range of vacuum tube types and models available, each with distinct characteristics, structures, operational requirements, and applications. These differences result in varying tonal qualities, meaning tubes cannot be arbitrarily interchanged. In preamps, triodes are typically preferred due to their excellent linearity, low noise levels, and moderate amplification factors. Triodes are well-suited for audio amplification, offering superior overall performance and sound quality while maintaining relatively straightforward circuitry.
Triodes exhibit a typical amplification factor of around 0.6 µ, with µ values generally ranging from 20 to 100. Consequently, the amplification factor usually does not exceed 70. For single-stage amplification circuits, selecting a triode with a higher µ value may be appropriate. On the other hand, using medium or low µ tubes often leads to greater stability. While certain European and American brands of vintage tubes have gained popularity through media hype, driving their prices skyward, it’s essential to approach this trend rationally. China boasts decades of experience in vacuum tube production and is the global leader in tube manufacturing. Many domestic brands enjoy international acclaim among audiophiles. Thus, when choosing tubes, it’s crucial to adopt a scientific and objective perspective, avoiding blind conformity or excessive bias towards specific brands.
Regarding triodes, domestically produced options like the 6N1, 6N2, 6N3, 6N4, 6N6, and 6N11 are highly regarded for their performance. When applied appropriately, these tubes can deliver outstanding sound quality comparable to any imported model. Interestingly, some popular foreign second-hand tubes available online may already be nearing the end of their usable lifespan. Among these, the 6N2 stands out as an excellent audio amplifier tube. Its specifications closely resemble those of the 12AX7, producing a similar sound profile, with only minor variations in filament pin configuration making replacement straightforward.
For instance, the 6N2 from Shanghai, Dawn, and Beijing showcases consistent build quality and performance. [Images: 6N2 tube schematic diagram, various manufacturer appearances] These images illustrate the physical attributes and pin configurations of the 6N2 tube across different manufacturers, highlighting their uniformity despite slight regional variations.
In summary, thoughtful consideration of tube selection and careful circuit design are paramount in achieving the desired audio performance in a tube preamp. By adhering to these principles, designers can craft equipment that delivers both technical excellence and auditory satisfaction.