Radial Engineering J48 MK2, User Manual

Page 1: ...ineering 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 J48 www radialeng com ...

Page 2: ...stions 13 Block diagram and specifications 15 Warranty Back cover 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 Ltd is a division of C TEC JP CableTek Electronics Ltd Features and specifications are subject to change without notice J48 MK2 Manual V3 1 05 20 05 part R800 9616 00 ...

Page 3: ...square wave distortion In fact every aspect of the J48 design has been optimized for maximum headroom while introducing minimal phase harmonic and inter modu lation distortion But this is not all the Radial J48 features a transformer that isolates 48V phantom power to help eliminate ground loops while removing hash and system noise This ensures that what you put in you get out Nothing altered noth...

Page 4: ...nectors against damage during hectic stage set ups 6 XLR male output This male XLR output connector is wired to the AES standard with pin 1 ground and pin 2 hot and puts out a 600 ohm mic level signal 7 Polarity reverse 180º This toggles the XLR pin 2 and pin 3 to interface with older equipment Also used when combining two sources mic DI on the same instrument to avoid phase cancellation 8 Low cut...

Page 5: ...litary grade double sided PC board provides maximum durability and added resistance against cold solder joints 14 Power supply transformer The transformer in the power supply helps eliminate ground loops by isolating the power coming in from the XLR s 48V phantom feed 15 Digital DC to DC switching power supply Steps up phantom power to produce higher internal rail voltage This provides more headro...

Page 6: ...e mixer and listen The J48 should be able to handle most instrument levels without any problems For exceptionally high signal levels such as from digital pianos sam plers and high output basses inserting the 15dB pad will reduce the input level to the active circuit If you hear distortion simply depress the 15dB pad To reduce low frequency mud and run away acoustic resonance the J48 is equipped wi...

Page 7: ...duce the most accurate picture of the source signal no matter what the instrument Direct boxes perform several important functions they are designed as impedance matching and signal balancing devices This means that they take the high impedance of a guitar or keyboard and transform it to the low impedance used in bal anced sound systems Balanced signals inherently cancel noise and due to their low...

Page 8: ...he instrument As the signal passes through the J48 to the XLR output it is converted to a balanced 600 Ohm low impedance signal This allows long cable runs without introducing noise into the audio signal path It is important to note that the output of the Radial J48 is mic level This allows the J48 to be used alongside microphone signals without introducing cross talk or causing saturation when dr...

Page 9: ... constantly working at its peak Harmonic distortion is reduced inter modulation distortion goes down and phase distortion is minimized The Radial J48 coasts along producing a less stressed and more musical sound Buzz and hum caused by ground loops Probably the most challenging aspect when setting up a sound system is reducing system noise The most common problem is buzz and hum due to ground loops...

Page 10: ...cian s amplifier For instance when using the J48 with a bass guitar this set up allows both the musician and the engineer to work with the original direct signal from the bass This way the musician can set up his sound on stage with his own EQ while the engineer can EQ the bass to better work in the hall True to the Music Radial Engineering J48 User Guide 8 Note On live stages it is common that ins...

Page 11: ...e to handle the signal This is why acoustic guitars often sound thin and scratchy It is all the more distressing with bass guitars and keyboards that have tremendous energy in the low end bass frequen cies Once the signal is distorted you cannot fix it in the mix The J48 is designed to handle these signal levels without fear of overloading and is one of the main advantages you will enjoy with your ...

Page 12: ... the power supply that will generally eliminate most of this type of noise But in severe cases depressing the ground lift switch can help When lifted you are actually breaking the internal ground path between the input and the output It should be noted that when you are going direct or connecting a bass or acoustic guitar to the Radial J48 without using the thru put the ground switch should be set...

Page 13: ...blems Reversing the polarity on the J48 will often alleviate this While recording this same process provides the engineer with another tonal pallet and experimenting with different settings can lead to some very pleasing results Mechanical attributes One common feature you will find on all Radial products is our relentless pursuit of durability Open up the J48 to look inside You will note that the ...

Page 14: ...r connecting typical 9V battery terminals to the PC board allowing it to be used with batteries Please contact your Radial dealer for information to convert your J48 from 48V phantom operation to battery power J Rak 19 rack mount kit You can rackmount the J48 using the J Rak This is a simple shelf that can rack mount up to eight J48s JDIs or any other similar sized Radial products in two RU spaces...

Page 15: ... signal to the instrument amplifier and the mixer created the added second load This of course would reduce the level going to the instrument amplifier and cause the sound to change Active DIs like the Radial J48 buffer or pre amplify the signal so that loading is never a problem What makes the Radial J48 so special Let s begin by understanding how active DI s work active direct boxes are in fact pr...

Page 16: ...le Then check all your cables Nine out of ten times cables are the culprits when it comes to no sound Is a flat frequency response better than a colored response This is a good question When buying a large condenser microphone you are not getting a flat mic but getting a color or flavor for your sound palette Most studios boast a selection of mics and the sign of a good engineer is one that knows whi...

Page 17: ...Unbalanced 220K Ohms Output impedance Balanced 600 Ohms Frequency response 10Hz to 80kHz Linear performance 0 12dB from 20Hz to 20kHz Total harmonic distortion 0 06 20Hz 0 005 1kHz Phase distortion 0 02º at 1kHz Maximum input voltage 3 12 Volts RMS 9V peak Size 3 5 wide 2 high 5 5 deep Weight 1kg or 2lbs Construction Welded 14 gauge steel Finish Baked enamel coat ...

Page 18: ... under this limited warranty the product must be returned prepaid in the original shipping container or equivalent to Radial or to an authorized Radial repair center and you must assume the risk of loss or damage A copy of the original invoice showing date of purchase and the dealer name must accompany any request for work to be performed under this limited warranty This limited warranty shall not...