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6 .

M A I N T E N A N C E

The VT-15 is built with only the highest quality parts and will prove to be extremely reliable. Vacuum tubes and electrolytic capacitors, however, have a finite useful life and must be replaced eventually.

Top Cover Removal

Removing the top cover allows access to the vacuum tubes, the VU meter calibration, and to sidechain alignment trimpots. Eighteen 6-32 phillips-head screws must be removed. When replacing the cover, position it so that the slotted ventilation holes are over the tubes (towards the back).

Bottom Cover Removal

WARNING! High voltages are exposed when the bottom cover of the VT-15 is removed. Refer all servicing to the factory or to technicians who are experienced in working on vacuum tube equipment. Voltages over 400 are used in the VT-15. Contact with these voltages could result in serious injury or death.

Removing the bottom cover allows access to the VT-15 circuitry, the pulse width modulator board adjustments, and the filament voltage adjustment. Eighteen 6-32 phillips-head screws must be removed.

Alignment

The VT-15 compressor is complicated to align and requires test equipment nor normally found in most studios. If alignment is required, the VT-15 should be returned to the factory, or contact the factory for detail alignment instructions. Mis-alignment of the VT-15 will result in very poor (and possibly bizarre) performance. Do not touch any adjustments!

Vacuum Tubes

Four 6072A tubes and two 6N1P tubes are used in the VT-15. If tube replacement is needed, contact the factory for instructions and tube layout. The 6072A mic preamp input tube and the compressor preamp tube are quite critical for proper performance. There can be as much as a 15 dB difference in noise level among an assortment of tubes, and the tubes used in these stages should be carefully chosen to maintain low noise. Selected low-noise tubes are avail- able from D. W. Fearn. Other tubes are far less critical and almost any quality off-the-shelf 6N1P will perform satisfactorily. 12AY7 tubes may be substituted for the 6072A tubes, but with reduced performance.

Tube life is difficult to predict, but it will probably be measured in years. Catastrophic tube failure is rare with this type of device, but a gradual increase in noise, microphonics, distor- tion, or a reduction in headroom, should indicate the need for replacement. It is recommend- ed that you periodically perform a quick noise and distortion check on the VT-15 and com- pare the results to previous measurements.

VT-15 Recording Channel

D.W. FEARN

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VT-15 specifications

The Crown Audio VT-15 is a robust loudspeaker system that has gained recognition for its advanced technologies and impressive audio performance, making it ideal for various applications, including live events, installations, and broadcast scenarios. Built with durability and sound quality in mind, the VT-15 serves both professionals and enthusiasts in the audio industry.

One of the standout features of the VT-15 is its high-efficiency design, which is achieved through advanced driver technology. The loudspeaker is equipped with a premium 15-inch woofer that delivers powerful low-end reproduction, ensuring a solid bass presence that enhances the overall listening experience. This, combined with a high-frequency compression driver that operates at 1 inch, ensures clear and articulate treble frequencies, resulting in a balanced sound profile suitable for different musical genres.

The VT-15 incorporates Crown’s patented Waveguide technology, designed to provide consistent and controlled sound dispersion. This feature allows the loudspeaker to effectively cover large areas without experiencing significant drop-off in audio fidelity, making it a great choice for medium to large venues. The controlled directivity also means that listeners in various positions within the space can enjoy a similar audio experience, enhancing the performance of any event.

Another defining characteristic of the VT-15 is its rugged construction. Built with a reinforced enclosure, it is designed to withstand the rigors of touring and heavy use in fixed installations. The cabinet is constructed from high-quality materials that minimize vibration and resonance, further contributing to the clarity of sound. Its lightweight design allows for easier transport and setup, making it a practical choice for audio professionals on the go.

In terms of connectivity and compatibility, the VT-15 features versatile input options, allowing it to integrate seamlessly with various audio systems. Whether used in conjunction with other Crown products or compatible equipment from different brands, the VT-15 ensures flexibility in configuration.

Overall, the Crown Audio VT-15 stands out as a high-performance loudspeaker that combines advanced technologies, durability, and sound fidelity. Its powerful drivers and innovative design make it a reliable choice for any professional audio application, providing users with the quality and performance they demand. Whether for live music, presentations, or installations, the VT-15 delivers exceptional audio experiences that elevate any event or setting.
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