User manual ART 355

[. . . ] **Note: If you experience a grounding hum when using both output connectors (one to the console, one to an instrument amp) simultaneously, a ground loop may be the problem. To remedy this problem, disconnect the ground wire (pin 1) from the XLR cable plugged into the Dual MP's output. This interrupts the ground path and therefore breaks the loop. Controls, Switches and Indicators Power The Dual MP is powered by an internal power supply. If the attached power cord ever becomes damaged, discontinue use until you can have it repaired. [. . . ] Turn the control clockwise to increase gain and counterclockwise to decrease gain. You may control two ranges of gain with this control, +26 to +60dB and +6 to +40dB. Sonic Character LED Array Four LEDs are provided on each channel which display how the tube gain is affecting the input signal. These LEDs are calibrated with the tube circuitry to give you an accurate visual of its output signal (**Note: these LEDs are pre - output level control). At this level, the tube is producing an output signal which most would call "warm" or (those ever over-used) "tube/ retro/ vintage/ rich/ etc/ etc". You'll find the output signal has an enhanced bottom to low mid quality with smooth high frequency detail. This LED will light at approximately 6dB before audible distortion occurs. The unique design of the Dual MP causes the tube to distort well before any other gain stage. When a tube goes into distortion it is a gradual process and tends to sound pleasing for a range before it turns into a distortion box. After some use you'll find the "sweet spot" of the Dual MP is with this light flashing fairly regularly. +20dB Gain/ Norm Switch Use the +20dB Gain/ Norm switch to set the gain range of the Input control. This allows the user to manipulate the tube gain to meet their sonic requirements. The 1/4" input has a high impedance preventing the loading of any device connected to it, making the Dual MP perfect for DI applications. Applications Preamp The main application of the Dual MP is a microphone preamplifier. Plug any microphone directly into either input and set the input and output controls to provide a healthy level into the next stage of your system. Plug the instrument into either input and use the XLR or 1/4 (or both) outputs to connect to your recorder, board or PA system. 2-mix Because of its low noise and excellent tonal qualities, the Dual MP is ideal for running mixes through before recording to DAT or cassette. Used as a mastering device, the Dual MP is capable of adding warmth and, set properly, gentle tube compression to the incoming signal. DOWN before "testing" the sound. When running one channel into another (cascading) you have the potential for upwards to 120 to 140dB of gain. A R T Dual MP Specifications Dimensions: 1. 75" H x 19" W x 6. 5" D Input Connections: XLR (balanced), 1/4" unbal. Input Impedance: XLR, 1/4" 2K ohms, 840K ohms Output Impedance: XLR, 1/4" 600 ohms, 300 ohms Maximum Input Level: XLR +14dBu Maximum Input Level: 1/4" +22dBu Maximum Output Level: XLR +28dBu Maximum Output Level: 1/4" +22dBu CMRR >75dB (typical @ 1kHz) Frequency Response 10Hz to 20kHz (+0, -1dB) Dynamic Range >100dB (20Hz to 20kHz) Total Harmonic Distortion(THD) <0. 1% (typical) Maximum Gain: XLR to XLR 70dB (typical) 1/4" to 1/4" 54dB (typical) XLR to 1/4" 64dB (typical) 1/4" to XLR 60dB (typical) Equivalent Input Noise (EIN) XLR to XLR -129dBu (`A' weighted) 1/4" to 1/4" -105dBu (`A' weighted) Power Requirements: 95-125VAC, 10W - (USA) Internal fuse Other power requirements configured for country of destination. 6 7 Warranty and Service Information Limited Warranty Warranty service for this unit will be provided by Applied Research and Technology, Inc. (A R T) warrants to the original purchaser that this product is free from defects in workmanship and materials for a period of three years from the date of purchase. A R T will, without charge, repair or replace, at its option, defective product or component parts upon prepaid delivery to the factory service department or authorized service center, accompanied by proof of purchase date in the form of a valid sales receipt. [. . . ] This warranty is void if the serial number is altered, defaced or removed. A R T reserves the right to make changes in design and make additions or improvements upon this product without any obligation to install the same on products previously manufactured. A R T should not be liable for any consequential damages, including without limitation damages resulting from the loss of use. Some states do not allow limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to you. [. . . ]