www.radialeng.com JPC User Guide Radial Engineering 1638 Kebet Way, Port Coquitlam BC V3C 5W9 tel: 604-942-1001 • fax: 604-942-1010 email: info@radialeng.com • web: www.radialeng.com Radial Engineering is a division of C•TEC (JP CableTek Electronics Ltd.
JPC USER GUIDE Consumer To Pro Stereo Direct Box TABLE OF CONTENTS PAGE Introduction ............................................................................. Input & output panel feature set .............................................. Inside view & features ............................................................. Design concept ....................................................................... Development ...........................................................................
True to the Music INTRODUCTION Congratulations on your purchase of the Radial JPC Stereo Direct Box The Radial JPC™ is an active ‘consumer to pro’ stereo direct box specifically developed for computer sound cards and electronic media. It features 1/4” TRS, 1/8” TRS and dual stereo RCA input connectors. All of which may be used as inputs, or thru-puts. The XLR outputs are transformer isolated to eradicate hum and buzz caused by ground loops.
True to the Music INPUT PANEL FEATURES OUTPUT PANEL FEATURES 1. –10dB pad reduces the level going into the JPC from loud sources that could overload the circuit and cause distortion. 6. Stereo ground lift toggle switch (on side). 7. Twin XLR male output connectors follow AES standard with Pin-1 ground and Pin-2 hot. 2. 48V Power on LEDs lets you know that phantom has been turned on and is powering the two channels. 8.
True to the Music INSIDE VIEW 10. Isolated XLR connectors to eliminate chassis ground potential. 11. Active balanced drive circuit for long cable runs without signal loss. 12. Transformers on both inputs provide 100% isolation to eliminate hum and noise causing ground loops. 13. Military grade PC board with full surface ground plane to reduce RF noise susceptibility. 14. Long life, high cycle rated push switches for reduced maintenance. 15.
True to the Music and cause solder joint failure. A full-bottom no-slip pad provides electrical insulation and mechanical isolation with plenty of ‘stay-put’ for use on hectic stages. And with its baked enamel finish, the Radial JPC will continue looking great for years! DESIGN CONCEPT The Radial JPC is a stereo direct box that has been specifically designed for use with computer sound cards and other consumer electronic products.
True to the Music DEVELOPMENT As with all clever products, the Radial JPC’s development stems from demands from field engineers trying to find a useful and simple solution to a problem or challenge. Today, engineers are talking full advantage of the power of media technology by integrating computers, video players and compact discs in their productions. But with the integration of ‘new technology’ comes the many challenges of connecting these ‘consumer’ devices to the world of professional audio.
True to the Music The JPC Active Hybrid Design Probably the single most troublesome aspect to system design is eliminating noise caused by so-called ground loops. Most consumer electronic products are designed to work on their own and as such, do not incorporate extra ‘problem solvers’ in their circuit design. You connect the computer to the sound card, the sound card to some battery operated speakers and voila; it all works fine! The trouble starts when you connect the computer to a pro sound system.
True to the Music USING THE RADIAL JPC 1. Make sure all levels are down before connecting! As the JPC employs standard 48V phantom powering from the mixing console, it automatically turns on when phantom power is activated. Make sure your system levels are turned off as activating phantom will caused a loud pop in the system when activated. The two power-on LEDs on the front panel will illuminate when phantom power is present. 2.
True to the Music SPECIFICATIONS & BLOCK DIAGRAM J•PC Specifications Frequency range Type Powering Size Weight Dynamic range Distortion Intermodulation distortion Phase distortion Linear response Input connections Output connections Radial Engineering 40Hz to 20kHz , (+/- 3dB) Active with isolated inputs 48-Volt phantom powered, 5mA draw 2” x 3” x 6” 1kg or 2lbs 80dB 0.5% at 1kHz with -10dB input Less than 1% Less than 5º at 100Hz, 0.
True to the Music FAQs Can I use the Radial JPC like a regular DI box for instruments? Although the Radial JPC was designed to work with computer sound cards and other consumer level hi-impedance devices, it can also be used with active instruments such as acoustic guitars that have built-in pick-up pre-amplifiers with internal batteries.
True to the Music Why not simply use a passive transformer as an interface? The problem here is both impedance matching a drive capability. A single good transformer is extremely expensive costing upwards to half the price of the JPC. Because we use an active circuit to drive the signal, we can employ amore cost effective 1:1 transformer to isolate and active electronics to do the balancing and impedance matching.
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RADIAL ENGINEERING (a division of J.P Cabletek Electronics Ltd.) “Radial” warrants this product to be free from defects in material and workmanship to the original owner and will remedy any such defects free of charge according to the terms of this warranty. Radial will repair or replace (at its option) any defective component(s) of this product (excluding batteries, finish and wear and tear on components under normal use) for a period of three (3) years from the original date of purchase.
