Radial Engineering JDV MK3 Owner's Manual

Radial JDV Mk3 Direct Box

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

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Owner’s manual

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Radial Engineering - 1638 Kebet Way, Port Coquitlam  BC  V3C 5W9 

tel: 604-942-1001 · fax: 604-942-1010       email: info@radialeng.com

Radial Engineering is a division of  JP Cabletek Electronics Ltd.

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PLEASE READ BEFORE CONNECTING ELECTRONIC DEVICES TO YOUR JDV!

Caution must be used when connecting electronic equipment to the 

JDV Mk3. The JDV Mk3 bridges all electronic equipment connected 

to it so faulty wiring or incorrect grounding of any of the equipment 

may cause a shock hazard to be present and/or damage to the JDV 

or other connected equipment. Because grounding schemes differ 

between manufacturers, it is important to check for correct polarity, 

in particular with older amplifiers using 2-prong ungrounded A/C 

cords. If the polarity is reversed on an ungrounded amplifier there 

may be a potential of 120V present between the amp chassis and 

ground. Radial Engineering takes no responsibility for this or how 

the JDV is connected or used. It is the users full responsibility to 

ensure that proper electrical polarity is maintained on all equipment 

connected to the JDV and that proper building electrical codes have 

been followed wherever the JDV is being used.

To reduce opportunity for shock hazard or damage to the JDV or 

connected  equipment, plug the ¼” connectors into the amplifiers 

first and then to the JDV. This is especially important when using old 

amplifiers that do not have 3-prong plugs as the possibility exists to 

touch the chassis ground with the connector plug tip when the plug 

is inserted into the jack.

Cautions for amplifiers with ungrounded 2-prong A/C cords:   

Before connecting the JDV to an ungrounded amplifier, power the 

amp up and listen to the residual hum. If the amp has a two-position 

ground polarity reverse switch,  set the switch in the position that 

produces the least residual hum from the speakers. If there is no 

polarity switch, reverse the A/C plug at the outlet to find the least 

residual hum.

To ensure an ungrounded amplifier does not present a shock 

hazard: Test for voltage potential by connecting a voltmeter 

between the amplifier chassis and the JDV chassis. If voltage is 

present, reverse the amplifier’s A/C supply polarity and test again.

Note that due to this potential problem, damage to the JDV or other 

connected equipment caused by improper A/C polarity is not 

covered under warranty. 

>>>>>>>> CAUTION <<<<<<<<