Model 750

2.Select the external audio source by placing front panel configuration DIP switch 1 to the down position.

3.Select the main bus as the VU meter source by placing the meter source select button to the out position.

4.Place the main output limiter/compres- sors to the off state by placing the button labeled LIMITER to the out position.

Figure 7. Detail of back panel showing trim pots for VU meter calibration

5.Set the main bus master output level controls to the unity gain position. The front panel contains a graphic arrow symbol and the letter “U” to serve as a guide.

6.Press and hold the button labeled TALK TO MAIN AND AUX. This con- nects the external audio source to the main and AUX audio buses.

7.With a “normal” voice signal coming from the external audio source, adjust the trim pot so that the VU meters deflect to the 0 VU position on signal peaks. You may want to enlist the help of another person to serve as a “live” audio source while you make the adjustment. It is very important that the external audio level reflect normal operation—if your operators or pro- ducers love to yell and scream, set the trim pot accordingly.

VU Meter Calibration

Two trim potentiometers allow calibration of the VU meter’s normal operating level. The range of the trim pots allow “0” on the meters to represent an output signal level of –2 to +10dBu. While providing a power- ful feature, these trim pots must be ad- justed very carefully. Be warned—meter calibration effects the audio performance of the entire Model 750! From the factory, the VU meters are calibrated so that 0 VU represents an output level of +4dBu on main output 1, when loaded with 100k ohms. In certain cases it may be a good idea to check the meter calibration, such as when main outputs 1 and 2 are loaded with 600 ohms, or when main output 3 is going to serve as the “primary” output.

In some installations it may be desirable to have a level different from +4dBu, such as

Model 750 User Guide

Issue 3, May 1997

Studio Technologies, Inc.

Page 19

Page 15 Page 17
Page 16
Image 16
Fostex 750 manual VU Meter Calibration
Page 15 Page 17

750 specifications

The Fostex 750 is a premium closed-back headphone that has garnered attention for its combination of advanced technology, comfort, and sound fidelity. Designed primarily for studio applications, the Fostex 750 delivers an exceptional listening experience that caters to both professionals and audiophiles alike.

One of the main features of the Fostex 750 is its dynamic driver technology. The headphones are equipped with large 50mm titanium-coated drivers that provide a powerful and clear sound reproduction. This driver configuration is engineered to deliver a wide frequency response, ranging from deep bass to sparkling highs, ensuring that every detail of the audio is captured. With an impedance of 25 Ohms, the headphones are highly efficient and can be easily driven by a variety of devices, including portable music players and digital audio converters.

Comfort is another highlight of the Fostex 750. The headphones feature plush ear pads made from soft polyurethane, which provide excellent cushioning for extended listening sessions. The adjustable headband offers a customizable fit, allowing users to achieve an optimal acoustic seal that enhances sound isolation. This is particularly beneficial in studio environments, where external noise can interfere with critical listening.

In terms of build quality, the Fostex 750 boasts a robust yet lightweight design. The combination of high-quality plastics and metal components contributes to its durability, while the foldable structure makes it portable and convenient for travel. This practicality is further enhanced by the detachable cable, which allows for easy replacement in case of wear.

Another notable technology integrated into the Fostex 750 is the use of new acoustic engineering principles. These headphones feature a closed-back design that minimizes sound leakage and provides an immersive listening experience. This design is complemented by the innovative bass reflex system, which enhances low-end response without compromising clarity in other frequency ranges.

Overall, the Fostex 750 is an impressive headphone that combines advanced sound technology, comfort, and durability. Its dynamic drivers, ergonomic design, and acoustic engineering make it an ideal choice for both professional monitoring and casual listening. Whether you are mixing in a studio or enjoying music on the go, the Fostex 750 delivers an unmatched audio experience that is sure to satisfy even the most discerning listeners.
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