ART 400 Series Precision Graphic Equalizers

Introduction

The ART 400 Series of Precision Graphic Equalizers are engineered to meet high standards for audio performance and functionality. They offer precision frequency tailoring, reliable performance, rugged design, and silent processing, making them suitable for virtually any audio application where these qualities are paramount.

Models

• ART 441: Dual Channel, 15 Band, 2/3 Octave Graphic Equalizer
• ART 451: Single Channel, 31 Band, 1/3 Octave Graphic Equalizer
• ART 455: Dual Channel, 31 Band, 1/3 Octave Graphic Equalizer

Key Features

General Information

Signal Levels and Grounding

Operating Instructions

Before equalizing, familiarize yourself with the controls. The unit features a bypass switch (red LED indicates bypass mode) for comparing equalized and unequalized signals. This bypass is a "hard-wire bypass" that routes the signal directly from input to output.

A range selection switch offers +/-6dB (green LED) or +/-12dB (yellow LED) gain. The output level control adjusts signal from off to +6dB. A red Clip LED illuminates when signals are within 4dB of clipping; occasional flickering is acceptable, but steady illumination requires level adjustment or reducing the output of the preceding component.

Initial Set Up

1. Set channel levels to the center detent (0dB) on the front panel.
2. Engage the Bypass switch (red LED ON).
3. Set the frequency slide controls to the center detent (or 0dB).
4. Select the 6dB range switch (green LED ON).
5. Apply signal to the system.
6. Release the bypass switch (red LED OFF).
7. If the Clip LED is ON, reduce the input level control.
8. Begin equalizing your system.
9. If more equalization control is needed, switch the range switch to the 12dB setting.

Front Panel Controls

1. POWER SWITCH

Press the upper or lower portion to turn the equalizer ON or OFF. CAUTION: Always turn your equalizer ON BEFORE your power amplifiers are turned on, and always turn OFF your equalizer AFTER your power amplifiers have been turned off.

2. FILTER LEVEL CONTROLS

Each slider controls the output level of its respective bandpass filter. A detent at the center position helps center the controls for a flat response.

3. FILTER RANGE SWITCH & INDICATORS

The gain range of the filter sliders is switchable (as a group) from +/-6dB to +/-12dB for maximum boost/cut capability. At 6dB, the green LED illuminates; at 12dB, the yellow LED illuminates.

4. BYPASS SWITCH & CLIP INDICATOR LED

Bypass Switch: When the red LED is illuminated, the unit or channel is in bypass mode. Signal is routed directly from input to output without passing through EQ circuitry. Use this switch to compare equalized and unequalized material, or to bypass the EQ section in case of power loss or unit failure.
Clip Indicator: This red LED illuminates if any section of the equalizer is within 4dB of clipping. Occasional flickering is acceptable, but if it remains on more than intermittently, you should turn down the equalizer's level controls or reduce the output level of the preceding component to avoid audible distortion.

5. HI PASS FILTER (LOW-CUT FREQUENCY CONTROL)

To cut down on unwanted low frequency signals, this control determines the roll-off frequency of the High-Pass Filter (HPF). The roll-off frequency can be adjusted from 10Hz to 250Hz. Because of its high roll-off slope, the HPF can be efficiently used to cut down "HUM" noise from preceding instruments, or to reduce low frequency resonances in enclosed acoustic environments.

6. LOW PASS FILTER (HIGH-CUT FREQUENCY CONTROL)

To cut down on unwanted high frequency signals, this control determines the roll-off frequency of the Low-Pass Filter (LPF). The roll-off frequency can be adjusted from 3kHz to 40kHz. Because of its high roll-off slope, the LPF can be effectively used to cut down high frequency noise from preceding instruments, or roll-off excessive high frequency sounds for a more natural sound.

7. LEVEL CONTROL

This controls the level of signal coming into the equalizer. Turn this control down if the Clip LED illuminates steadily (indicating too strong an input signal). Unity gain can be set by turning this knob to the center detent position. Signal levels should be kept normalized; the bypassed signal level should be the same or slightly lower than the active EQ gain.

Rear Panel Connectors & Controls

8. POWER CORD

Connects the AC power source to the equalizer. CAUTION: Equipment for USA installation includes a three-pin polarized plug; do not remove the center grounding pin.

9. FUSE HOLDER

Contains the AC primary fuse. Replace with the same type fuse if blown (0.5Amp for 95-125VAC or 220-240VAC). If fuses blow repeatedly, stop replacing them and refer servicing to qualified personnel.

10. AC VOLTAGE SELECTOR

Set this slide switch to match your line voltage supply. CAUTION: For new installations or portable systems, or when mains power is suspect, confirm appropriate voltage and line polarity BEFORE connecting the instrument to the power source.

11. GROUND LIFT SWITCH

This switch disconnects signal ground from the mains and chassis earth ground. Set the switch to the LIFT position if "Hum", caused by a ground loop, can be heard at the speakers.

12. INPUT/OUTPUT CONNECTORS

• 1/4" TRS: Balanced and wired as Tip = High (+), Ring = Low (-), and Sleeve = Ground.
• XLR: Balanced and wired as Pin 2 = High (+), Pin 3 = Low (-), and Pin 1 = Ground.
• RCA PHONO: Unbalanced, wired as Tip = High (+) and Sleeve = Ground.

CAUTION: Only one of these sockets should be chosen for audio connection at the same time.

Applications

Graphic equalizers may be used wherever modification of the frequency contour of a sound system is needed. A graphic equalizer is a solution to many sound problems or creative urges.

Specifications

Warranty Information

Limited Warranty

Applied Research and Technology (ART) warrants this product and its components to be free from defects in workmanship and materials for a period of one year from the date of purchase. ART will, at its option, repair or replace defective products or component parts upon prepaid delivery to the factory service department or an authorized service center, accompanied by proof of purchase date in the form of a valid sales receipt.

Exclusions

This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs. This warranty is void if the serial number is altered, defaced, or removed. ART reserves the right to make changes in design or make additions to or improvements upon this product without any obligation to install the same on products previously manufactured. ART shall not be liable for any consequential damages, including without limitation damages resulting from loss of use. Some states do not allow limitations of incidental or consequential damages, so the above limitation or exclusion may not apply to you. This warranty gives you specific rights and you may have other rights, which vary from state to state.

For units purchased outside the United States, an authorized distributor of Applied Research and Technology will provide service.

Service

The following information is provided in the unlikely event that your unit requires service:

1. Be sure that the unit is the cause of the problem. Check to make sure the unit has power supplied, all cables are connected correctly, and the cables themselves are in working condition.
2. If you find the unit to be at fault, write down a complete description of the problem, including how and when the problem occurs. Please write down a description of your complete setup before calling Customer Service.
3. Contact our Customer Service department at (585) 436-2720 for your Return Authorization number or questions regarding technical assistance or repairs. Customer Service hours are 9:00 AM to 5:00 PM Eastern Time, Monday through Friday.
4. Pack the unit in its original carton or a reasonable substitute. The packing box is not recommended as a shipping carton. Put the packaged unit in another box for shipping. Print the RA number clearly on the outside of the shipping box. Print your return shipping address on the outside of the box.
5. Include with your unit: a return shipping address (we cannot ship to a P.O. Box), a copy of your purchase receipt, a daytime phone number, and a description of the problem.
6. Ship only your unit (keep your manual!) to:
   APPLIED RESEARCH AND TECHNOLOGY
   215 TREMONT STREET
   ROCHESTER, NEW YORK 14608
   ATTN: REPAIR DEPARTMENT
   RA# ____________________

Contact Information

APPLIED RESEARCH & TECHNOLOGY
215 TREMONT STREET
ROCHESTER, NEW YORK 14608 USA

(585) 436-2720 – Voice
(585) 436-3942 – Fax

Website: www.artproaudio.com
Email: cserve@artproaudio.com