jdi stereo user guide jensen transformer equipped passive direct box Radial Engineering Ltd. 1588 Kebet Way, Port Coquitlam BC V3C 5M5 Tel: 604-942-1001 • Fax: 604-942-1010 • Email: info@radialeng.
radial jdi stereo passive direct box user guide Introduction........................................................................................ 1 JDI Stereo Features ������������������������������������������������������������������������� 2 Making Connections ������������������������������������������������������������������������� 3 Using the PAD...................................................................................
FEATURES 1. -15dB PAD: Reduces the input sensitivity of the left channel to prevent overload. 2. ¼” INPUTS: Left and right unbalanced, hi-Z inputs used to connect instruments. 3. ¼” THRU-PUTS: Left and right parallel outputs used to connect the hi-Z instrument signal to an amplifier, tuner or personal monitoring system. 4. -15dB PAD: Reduces the input sensitivity of the right channel to prevent overload. 5.
OVERVIEW The Radial JDI is a passive direct box. This means that it does not require any power to make it work. You simply plug in and it will quietly go to work. Further, as the JDI Stereo employs transformers, these naturally block stray DC voltage that can cause system noise. This also means that 48V phantom power as used with condenser microphones will not harm the JDI Stereo.
USING THE -25dB PAD Inside the JDI Stereo are two high performance Jensen transformers. These can be hit hard with plenty of level without worry. In fact, many artists and engineers enjoy the sound of the JDI when pushed hard as it will exhibit a natural compression when the transformer is pushed towards saturation. There are however instances when the output from an instrument can be extreme. To prevent from excessive saturation, the JDI Stereo has a -15dB input pad that reduces the input sensitivity.
PASSIVE VS. ACTIVE As a direct box, the JDI Stereo will work with almost any instrument. It is however important to understand a few fundamentals. The JDI Stereo is passive. This means that it does not require any power to make it work. This also means that it employs the signal from the source instrument as the ‘drive’ which produces the balanced signal for the PA system or recorder. This also means that if the input signal is very low, there may not be a strong enough signal to effectively drive the JDI.
understanding loading A problem that was detected early on was the sound or effect that a transformer can impose on an instrument. Back in the early days of direct boxes, 600Ω broadcast or telephone transformers were used. These had such a low impedance that almost half of the signal from the instrument would be sent to the mixing desk, leaving very little left for the musician’s amp on stage. Passive basses would sound listless and have no punch.
OPTIONAL RACK MOUNTING KITS The J-Rak 8 and J-Rak 4 are an innovative rack mount chassis. The J-Rak 8 has eight vertical slots for Radial JDI Stereo direct boxes or the other Radial J-Class products. The J-Rak 4 has four horizontal slots. J-Rak 8 J-Rak 4 Each direct box can be front or rear mounted allowing the system designer to have the XLR’s on the front of the rack or rear, depending on the application.
SPECIFICATIONS Audio circuit type: ������������������������������������������������������������������������������������������������������������������� Passive, transformer isolated Frequency response: �������������������������������������������������������������������������������������������������������������������������� 20Hz ~ 20KHz (±3db) Dynamic range: ���������������������������������������������������������������������������������������������������������������������������������������������������������
BLOCK DIAGRAM TRANSFORMER PAD SWITCH 1/4” PHONE JACKS TRANSFORMER PAD SWITCH 1/4” PHONE JACKS Radial Engineering Ltd.
RADIAL ENGINEERING 3 YEAR TRANSFERABLE WARRANTY RADIAL ENGINEERING LTD. (“Radial”) warrants this product to be free from defects in material and workmanship 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 finish and wear and tear on components under normal use) for a period of three (3) years from the original date of purchase.
