Model | Fostex 750 specification

Model 750

0dBu, to serve as the “0” reference. While Studio Technologies is not excited about such a prospect, it can certainly be achieved. There is one serious downside to changing the nominal operating level; the limiter/compressor threshold. The limiter/compressors are designed to activate at approximately 6dB above the Model 750’s internal operating level, corresponding to an output level of +10dBu. The threshold is not factory calibrated and is not easily modified in the field. If, as an example, the meters are re- calibrated for a nominal output level of 0dBu, the limiter/compressors will now activate at 10dB above this new nominal level. Prior to changing the operating level, a discussion with personnel at the factory may be warranted. Call us for a chat!

While not difficult, meter calibration is a bit tedious:

1.Ensure that mains power is connected to the Model 750.

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

3.Activate the setup section’s single tone output by placing the single tone button to the on (in) position. The voice and multi-tone buttons should be in their off (out) position.

4.On the setup section, place the main bus assignment button to the on (in) position.

5.Select the main bus as the VU meter source by placing the meter source button to the monitor (in) position and selecting main stereo. This makes the meters most accurate when they are

monitoring the main bus via the moni- tor section. If you wish to have the meters most accurate when they are connected directly to the main bus, set the meter source button to the main (out) position.

6.Designate main output 1, 2, or, in rare circumstances, 3 as the desired “primary” output. This is the output that the meters will be calibrated against. If main output 3 is selected, set its output level button to the line (in) position.

7.Confirm that the left and right channels of the designated main output are terminated with their normal load impedance.

8.Using an appropriate adapter cable, connect an audio level meter directly across the left channel of the desig- nated main output. Ensure that the meter connection does not remove the normal load. The level meter must be a precision device that’s intended for audio use—a general-purpose volt- meter is not adequate!

9.Carefully observing the audio level meter, set the main bus left channel master output control so that the out- put level matches the desired nominal operating level. In most cases this will be +4dBu.

10.Observing the Model 750’s left channel VU meter, adjust the left channel meter trim pot to give 0 VU.

11.Repeat steps 8 through 10, this time for the right channel.

Issue 3, May 1997	Model 750 User Guide
Page 20	Studio Technologies, Inc.

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.