Tips & Advice

A Word About Low Level Tubes

The small tubes (Voltage Amplifier/Phase Splitter and Driver) in the VAC Amplifiers are type 12AU7. This tube is essentially the same as types 12AU7A, 5814, 6189, CV4003, ECC82, and E82CC. The quality of the tube used is by far more important than which of these (equivalent) types is used.

The preferred 12AU7A is the British/Chinese Golden Dragon. Acceptable alternate versions include the Brimar CV4003 (ladder plate version), Mullard CV4003 (very midrangy), generic Chinese 12AU7 (brighter), Sylvania 6189 (darker sound), the GE 12AU7A (slightly forward and grainy) and the Yugoslavian 12AU7 (cohesive and somewhat coarse).

Many classic tubes worth trying if you have access to them, such as those from Telefunken and Amperex, although a caution is in order, as we have recently seen East German EL34 relabelled "Telefunken West Germany." Tubes actually manufactured by RCA, Westinghouse, and Sylvania can be quite good, but the name on the tube doesn't always indicate who actually made it. Other names to watch for are Valvo, Mazda, Tung-Sol, Bendix, Mullard, Brimar, and Raytheon.

TIPS & ADVICE

A Word About Bias Levels

The output stage is designed to operate in rich Class AB1 at an idle current of 70 milliamperes per tube, at approximately 535 VDC across the tubes. For more technical information about classes of operation see VAC Technical Monograph 90-8.

Some designers erroneously market a lower voltage and current operating point (as little as 26 mA @ 550 VDC) as "Class A1." Be assured that the VAC and its tubes are strong enough to handle the more demanding, richer bias level.

VAC PA100/100 specifications

The Mazda VAC PA100/100 is a pioneering innovation in the realm of automotive engineering, specifically designed to enhance driving dynamics and ensure optimal performance. This cutting-edge vehicle is recognized for its unique blend of advanced technologies and outstanding characteristics, making it a standout in the competitive landscape of modern automobiles.

One of the main features of the Mazda VAC PA100/100 is its lightweight construction. Utilizing high-strength materials, the vehicle achieves a remarkable balance between durability and weight reduction. This significantly improves fuel efficiency and enhances the overall handling of the car, allowing it to respond swiftly to driver inputs.

Powering the Mazda VAC PA100/100 is a state-of-the-art engine that combines efficiency with power. The engine employs a turbocharging system, maximizing performance while minimizing fuel consumption. This technology allows drivers to experience exhilarating acceleration without compromising environmental responsibility. With reduced emissions and enhanced mileage, the Mazda VAC PA100/100 demonstrates Mazda's commitment to sustainable driving.

The vehicle is also equipped with an advanced suspension system that optimizes ride comfort and handling. This system adapts to various driving conditions, ensuring stability and control regardless of the terrain. Drivers can expect a smooth ride with minimal body roll, which promotes confidence on tight corners and rough roads alike.

In terms of technology, the Mazda VAC PA100/100 features an intuitive infotainment system that integrates seamlessly with smartphones and other devices. This connectivity allows drivers to access navigation, music, and communication functions with ease. Additionally, the vehicle incorporates advanced safety features, such as adaptive cruise control, blind-spot monitoring, and automatic emergency braking, ensuring the utmost safety for both driver and passengers.

Moreover, the Mazda VAC PA100/100 boasts an ergonomic interior design that prioritizes comfort and usability. Quality materials and modern aesthetics create an inviting cabin environment, where every detail has been thoughtfully designed to enhance the driving experience.

In summary, the Mazda VAC PA100/100 is a remarkable vehicle that combines innovative technologies, exceptional performance, and a commitment to sustainability. With its lightweight structure, powerful engine, advanced suspension, and cutting-edge safety and infotainment features, it sets a new standard in the automotive industry, offering drivers an unparalleled driving experience that is both enjoyable and responsible.