background image

Radial Engineering Ltd.

JDV-Pre

 500 Module

True to the Music

®

2

JDV-PRE OVERVIEW

The JDV-Pre is a preamp dedicated to instruments. In other words, when we designed the 
JDV-Pre, our goal was to deliver a device that would be equally effective at amplifying a 
guitar, violin, mandolin or a contra-bass. So we started by optimizing the front end for the 
most natural tone and widest possible bandwidth. We then added a variable low-cut fi lter that 
would enable the engineer to ‘size’ the preamp so that it would translate the instrument’s true 
character while eliminating problem resonance. 

As we developed the design, it became abundantly clear that instruments are amplifi ed in 
many different ways depending on the transducer. In our audio world, a transducer captures 
vibrations and converts them into an electrical impulse.  This can be in the form of a magnetic 
pickup that captures the vibrations of a string, a piezo element that captures the vibrations 
at the bridge or even a microphone capturing the vibrations of sound as it travels through 
the air. 

Passive Piezo

Element

Magnetic &

Active Pickups

Condenser 

Instrument Mic

Instrument

Amplifi er

Live PA
System

Multi-track 

Recorder

Each transducer reacts differently to an electrical circuit. For instance a magnetic pickup 
sounds warmest when the impedance is set around the 200k-Ohm mark. A piezo really 
works best when the impedance approaches 4meg-ohms. And with condenser and dynamic 
microphones, one has to consider 48V phantom power, the input impedance and of course 
how much gain you introduce. The more gain, the more opportunity for noise. The more noise 
fi ltering you employ, the more you can affect the instrument’s natural harmonics. Great care 
is needed all the way along. 

Once you captured the source, the next goal is to send it along to one or more destinations. 
For instance when recording, the JDV-Pre must produce a +4dB balanced line output to feed 
digital audio workstation and a thru-put for the musician’s amplifi er. On a live stage, the JDV-
Pre must also be able to feed the artist’s instrument amp and produce a mic-level output like 
a direct box so that it can feed a snake system.  

The JDV-Pre user’s guide follows the fl ow chart above and discusses how each of these 
functions is addressed.  Let’s get started! 

Содержание JDV-Pre 500

Страница 1: ... to the Music User Guide JDV Pre 500 Instrument Preamp and DI 500 Series Module www radialeng com Radial Engineering Ltd 1588 Kebet Way Port Coquitlam British Columbia Canada V3C 5M5 tel 604 942 1001 fax 604 942 1010 email info radialeng com ...

Страница 2: ...user serviceable parts inside Radial JDV Pre 500 User Guide Table of Contents Page Feature Set 1 Overview 2 Getting Started 4 Using and Adjustments 6 Specifications 9 Block Diagram 9 Warranty Back cover Congratulations you ve done it You have invested in what we believe is one of the most musical sounding instrument preamps ever made The JDV Pre went through many design revisions before we finally d...

Страница 3: ... smoother more natural tone Great for bass and guitar 6 LED INDICATORS For power signal present peak overload and phantom power provide visual feedback of the JDV Pre operating status 7 INPUT Used to connect high impedance instruments to the JDV Pre This front switching jack has priority over the XLR mic input on rear panel of 500 series rack 8 AUX OUT Buffered output used to feed a guitar amplifie...

Страница 4: ...rough the air Passive Piezo Element Magnetic Active Pickups Condenser Instrument Mic Instrument Amplifier Live PA System Multi track Recorder Each transducer reacts differently to an electrical circuit For instance a magnetic pickup sounds warmest when the impedance is set around the 200k Ohm mark A piezo really works best when the impedance approaches 4meg ohms And with condenser and dynamic micro...

Страница 5: ...ance microphone There are three outputs on the JDV The front panel aux out which is used as a thru put to the guitar or bass amplifier when recording the XLR output on the 500 rack and if you are using it with a Workhorse the Omniport which in this case is set up as a balanced low impedance direct box output mic level INPUT OMNIPORT FEED LINK 1 OFF OFF CARD SLOT 1 OUTPUT OUTPUT INPUT G G G Line Lev...

Страница 6: ...pickups to a variable load that ranges from 22k Ohms to 500k Ohms Begin by setting the Drag Control to 12 o clock Then turn it clockwise The sound will become brighter with greater clarity As you turn it counter clockwise the tone will warm up and sound smoother Setting the Drag is particularly important if you intend to Reamp the signal down the way read more about Reamping later in this manual B...

Страница 7: ...y to background noise and hiss Therefore most manufacturers compromise by using a 1meg ohm input This results in an acceptable sound that is functional on a live stage But what few realise is that if you couple the output of a piezo transducer directly to a really good high impedance preamp you can produce sounds that are as good as a condenser microphone The JDV Pre has been carefully crafted wit...

Страница 8: ...nstead of going from say 1 to 100 distortion like an active circuit the distortion increases gradually They naturally compress to create a sonic effect that folks refer to as vintage When used on acoustic instruments that are typified with fast transient peaks such as a banjo acoustic guitar or mandolin the transformer gently smoothes out the tone Connection is made using the rear panel XLR input o...

Страница 9: ...new at recording we felt it would be good to discuss a standard recording setup Generally speaking if you are recording an acoustic instrument the instrument is connected to the JDV Pre and the output will be sent directly to the recording system Playback for monitoring is normally done via headphones When recording electric instruments like a guitar the process tends to be a little different as t...

Страница 10: ... Connector GROUND MIX BUSS XLR INPUT 48V PHANTOM POWER DRAG CONTROL FET INPUT BUFFER AUX OUTPUT BUFFER FRONT PANEL AUX OUT FRONT PANEL AUX OUT UNITY GAIN FRONT PANEL AUX OUT VARIABLE GAIN HIGH PASS FILTER ACCUSTATE VARIABLE GAIN STAGE XLR OUTPUT MIX BUSS DRIVER OMNIPORT MIC LEVEL BAL OUTPUT 4 7K Peak LED FRONT PANEL INSTRUMENT INPUT Signal LED 180 POLARITY REVERSE 1 2 3 1 2 3 ...

Страница 11: ...s XLR Output Dynamic range 93db Equivalent Input Noise 90dbu Input Gain Control at 5 Frequency Response 20Hz 20kHz 2 dB Front Panel Connectors Instrument Output Aux Output Gain Maximum 1 4 Front 26db Input Gain Control at 10 Gain Maximum XLR Rear 46db Input Gain Control at 10 Gain Omniport 20db fixed With relation to 1 4 input Input Rear Panel XLR Transformer Isolated Microphone Level With Phantom ...

Страница 12: ... the product has been damaged due to abuse misuse misapplication accident or as a result of service or modification by any other than an authorized Radial repair centre THERE ARE NO EXPRESSED WARRANTIES OTHER THAN THOSE ON THE FACE HEREOF AND DESCRIBEDABOVE NO WARRANTIES WHETHER EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR P...

Отзывы: