Operating Manual - PQX 571 and PQX 572 Parametric Equalizer

4.3Grounding

The terminal strip has two ground con- nections, one for input ground and one for chassis ground. The equalizer is shipped with a jumper strap connecting these two grounds. Normally, this strap should be left in place so the chassis and input grounds are connected. In a rack-mount installation where the equalizer is connected to other equipment with unbalanced inputs or out- puts, and the rack itself provides a good electrical connection between the equalizer chassis and the

other equipment, it may be desirable to remove this strap to isolate the input ground from chassis ground and avoid a ground loop. Unless you have such an installation and have a hum problem you can’t solve by other means (ie: using balanced input and output connections), leave the ground jumper strap in place.

5.CONTROLS

5.1Low Shelving Filter (Filter No. 1)

1.Low Shelf Level

The nature of a shelving filter is such that the fre- quency response ramps up to a plateau and then levels off again, hence the term “shelf”. This level control knob ad- justs the boost or cut of the signal below the tuned filter fre- quency as selected by its outer concentric frequency knob. The level which is indicated on the panel dial is the decibel level of the flat portion of the shelf. (see drawing)

2. Low Shelf Frequency

This control adjusts the frequency below which the shelving filter affects the level. The frequency which is indicated on the panel dial is the midpoint of the shelf’s sloping response.

Low Shelf Level Response

5.2Parametric Filters (Filters No. 2-6)

1.Range Switch

Each parametric filter has a normal center fre- quency range of 200Hz-20KHz. Depressing the range switch divides the center frequency by 10, providing a range of 20Hz-2KHz.

2. Level Control

The band of frequencies selected by the frequency and bandwidth controls are increased or decreased up to 15dB by this control.

3. Frequency Control

This outer concentric knob adjusts the center fre- quency of the filter action. Tick marks on the face panel are calibrated to ISO 1/3 octave center frequencies.

4. Bandwidth Control

This inner concentric Knob allows control of the width of frequencies around the center frequency (some- times called “Q”), and is a key reason parametric equaliz- ers are such a precise tool. With it, you can affect a wide (3.3 octaves) response, or a narrow (.05 octaves) band. To give an example, you could effectively boost or cut by 15dB a middle C on the piano without affecting the adja- cent B or D at all!

5. EQ In/Out Switch

The individual filter is engaged by depressing this switch. Since the filter is bypassed when the EQ switch is out, it is recommended that the EQ switch be out when no filter action is required. This is preferable to “zero- ing” the level control when considering optimum noise performance.

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Ashly PQX-572, PQX-571 manual Grounding, Controls, Low Shelving Filter Filter No, Parametric Filters Filters No
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PQX-571, PQX-572 specifications

The Ashly PQX-572 and PQX-571 are advanced audio processing devices designed to enhance sound quality in professional audio applications. Known for their exceptional performance and reliability, these two models are vital tools for sound engineers and audio professionals. Both devices integrate cutting-edge technologies that enable them to deliver superior sonic precision.

Starting with the Ashly PQX-572, this model serves as a 2-channel parametric equalizer that offers extensive control over audio frequencies. One of its standout features is the adjustable Q factor, which allows users to fine-tune the bandwidth of each frequency band. This feature enables precise adjustments, making it easier to eliminate unwanted resonances or enhance desirable frequencies. The PQX-572 also incorporates 20 Hz to 20 kHz frequency ranges, which ensure that audio processing can be applied across the audible spectrum, accommodating diverse audio sources.

Equipped with high-headroom circuitry, the PQX-572 provides low distortion levels, allowing for clean and transparent audio processing. Its front panel includes intuitive rotary controls for gain, frequency, and Q, enabling real-time adjustments during any audio session. Additionally, the device features bypass switches for each channel, providing flexibility when comparing processed and unprocessed audio.

On the other hand, the Ashly PQX-571, a single-channel version, shares many features with its twin yet possesses its unique strengths. This model is especially beneficial in setups where space is a concern since it occupies a single rack unit. The PQX-571 is ideal for musicians, small venues, and mobile setups that require high-quality sound processing without extensive equipment.

The PQX-571 maintains the same stellar audio performance found in the PQX-572, offering discrete, high-performance circuitry and low-noise operation. It also provides similar capabilities in frequency adjustment, emphasizing the importance of flexibility in audio manipulation. Both models are ruggedly built, making them suitable for various environments, from recording studios to live sound applications.

In summary, the Ashly PQX-572 and PQX-571 are robust audio tools designed for precise sound control and exceptional audio quality. Their intuitive interfaces and advanced features make them essential components for any audio professional looking to elevate their sound production capabilities. Whether in a recording studio, live venue, or mobile setup, these devices deliver performance and reliability that audio engineers can trust.
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