TIPS & ADVICE

A Word About Impedance Matching

We strongly suggest that you experiment with the three available impedance connections for the best sonic match with your system. Since no loudspeaker represents an unchanging impedance at all frequencies, it is impossible to assert with certainty which output tap is appropriate to use. In many systems an amazing difference in sound will exist between the various impedance taps.

You should consider the output impedance markings on your VAC Power Amplifier as follows:

"8 ohms" matches loads between 4 ohms and 8 ohms "4 ohms" matches loads between 2 ohms and 4 ohms "2 ohms" matches loads between 1 ohm and 2 ohms

Most loudspeakers vary outside of any one of these ranges, which is why experimentation is essential. We often find that matching a speaker's minimum impedance is more important than matching its nominal (average) impedance.

If you bi-wire your system (run separate speaker leads from the amplifier to the high and low frequency transducers) you may discover that two different impedance taps work best. For example, with early Martin Logan Sequel II we find that the bass speaker is best matched with the 4 ohm tap, while the electrostatic panel is best controlled by the 2 ohm tap. To achieve this connection, the black leads of both speaker cables connect to "G", the red lead for the panel connects to "2", and the red lead for the woofer connects to "4". With later Sequels we use the 4 ohm connection for both drivers.

Contrary to popular misconception, no power is lost due to unused output taps. Also, the amount of negative loop feedback in the amplifier does not change, being fixed at approximately 6 decibels for all output taps. For more information consult VAC Technical Monograph 90-9.

TIPS & ADVICE

A Word About Output Stage Operating Mode (triode internal wiring option)

Triode amplification is the oldest form known, while partial triode ("ultra-linear") operation of pentodes and beam power tubes dates to 1937. From the engineering perspective, the triode mode differs from the ultra- linear mode in the following ways:

1)Somewhat more distortion at low power levels

2)Somewhat less distortion at moderate power levels

3)Reduced maximum power output

4)Output impedance matching is somewhat less critical

5)Increased damping factor.

The ultra-linear mode applies negative voltage feedback from the primary of the output transformer to the screens of the output tubes. The ultra-linear circuit displays different characteristics (efficiency, distortion components and levels, etc.) depending upon how much of the primary winding is common to both the screen and plate of the output tubes. The VAC implementation of the ultra-linear circuit has been selected to achieve performance quality as close to pure triode as possible while still increasing power output and efficiency.

VAC can provide directions allowing a skilled technician to convert the output stage to triode operation.

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Mazda VAC PA100/100 user service Tips & Advice
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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.
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