Model | Fostex 750 instruction

Model 750

Changing the on/off status of the low-cut filter will result in little or no noise being added to the audio signal. While it is better to set the filter’s button to the desired position prior to being “live,” it can cer- tainly be used at any time.

Phase Reverse

The button associated with the “circle- with-a-slash” graphic symbol is used to select the phase reverse function. (Many people will know this as, and is techni- cally, a polarity invert or polarity reverse function.) In the normal (out) position, the mic or line input signal maintains the same polarity from input all the way through to the main and AUX audio buses. In the reverse (in) position, the signal is inverted by 180 degrees. Changing from normal to reverse, or vice-versa, will generally result in little or no audio “clicks” or “pops,” being generated, allowing the function to be used during “on-air” situations.

This function can be useful in situations where multiple microphones are present, and signal cancellation problems occur. The cancellation can be caused by mis- wired interconnecting cables, faulty equip- ment, or acoustic conditions related to microphone placement. As signal cancel- lation is not a trivial subject, we recom- mend that you consult one of the many fine audio textbooks that are available. We’ll leave it to you to use the function as required.

Status LED

Abi-color LED acts as a user-confidence indication of the overall signal level in the mic/line input channel’s circuitry. The LED will light with the color green as a signal present indicator, showing that the input signal, along with the gain of the input

preamplifier, is at least 18dB below the nominal internal operating level. The LED will light with the color red as a peak signal indicator, showing that the input signal, along with gain of the preamplifier, is within 6dB of the circuitry’s maximum level.

Rotary Controls

To address space considerations, the two rotary controls associated with each mic/ line input channel share the same front panel space; they’re known as “concentric pots.” The inner control allows adjustment of the preamplifier gain, the outer acts as a “pan-pot.”

Level Control

The inner control is labeled LEVEL, and is used to adjust the gain of the input pream- plifier circuit. In the fully counterclockwise position the preamplifier gain is set to its minimum, and full attenuation is achieved. This means that no signal continues on to the next stage of the mic/line input circuitry and, if configured, to the configurable output on the back panel. As the level control is rotated in the clockwise direction the gain of the preamplifier increases.

Pan Pot

The outer control is labeled PAN, and serves as a pan pot (panorama potentiom- eter), controlling the routing of the mic/line signal to the left and right channels of the main and AUX audio buses. (Of course the bus assignment buttons must be in the on (in) position for the signal to actually be connected to the buses.)

When the pan pot is in the fully counter- clockwise position, signal is sent only to the left mix buses; fully clockwise only to the right. A mechanical “detent” provides

Issue 3, May 1997	Model 750 User Guide
Page 24	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.