fig 1
Instructions For The RG-03 Player - Pickup For Spider Bridged Instruments
Before You Start, A Word About Amplification:
RG-03 passive pickups have been designed to operate properly and sound good without the use of a preamp when plugged into any normal electric guitar amp.
As a non-preamped piezo pickup the RG-03 has an impedance of approximately 2 mega ohms which most electric guitar amps will handle. As with any passive
pickup, the sound can be further enhanced and EQ'd with an outboard preamp.
PA systems:
If you require the added ability to be able to plug directly into a P.A. or mixer then a preamp designed for pickups will be necessary. The preamps that
are built into PA systems are microphone preamps and generally will not work properly with a passive pickup.
Acoustic Amps:
If you are plugging into an acoustic amp a preamp may be required depending upon the design of that acoustic amp. Acoustic amps may or may
not require the use of a preamp with a passive pickup and that will depend upon whether or not there is a special built in preamp section within that amp that
specifically allows for the choice of plugging in either a passive (non-preamped) or active (preamped) pickup. This choice is quite often a second channel or a
pushbutton on the amp's control panel. Many acoustic amps show a selection that may indicate the choice of 'high impedance' and 'low impedance'. Low impedance
in these instances usually indicates that in this range the amp will handle an impedance of 1000 ohms or less - which will allow active pickups with preamps to be
used.
High impedance in these instances may indicate an allowable impedance in the 2 or 3 mega ohm range - which will allow passive pickups to be used. Or it may
indicate a maximum input impedance allowed of 20,000 ohms or less - which will handle magnetic electric guitar
pickups but not passive pickups. You should carefully read the technical specifications of your acoustic amp in order
to see what it will do.
This pickup is designed to work on "Dobro" type guitars with a spider bridge. Tools that you will need are: electric
hand drill, assorted drill bits, assorted screw drivers, wire cutters / strippers, an old guitar string, a bit of masking
tape, and a low wattage soldering iron and a bit of solder.
Starting Installation
1) Slack off the strings, remove them from the tailpiece and tape them away from the cover plate. Remove the cover
plate screws and set the cover plate aside. Remove the tailpiece and resonator cone complete with the spider
bridge and set the rest of the guitar aside.
2) Remove the screw that connects the spider bridge to the resonator cone. There are two replacement screws
provided, one is a 3 mm. metric, the other is a 4-40. Check to see which of the two screws fits your resonator cone
properly. The correct screw should thread in very easily, do not force it. Also, make sure that the head of the
replacement screw fits into the saddle slot properly. If the screw head is too large to fit in the slot, grind off or file
away whatever small amount of the head diameter is necessary to make it fit in the slot properly. Once the screw is properly fitted, use it to snugly attach the spider to
the cone.
3) It is suggested that at this point you reinstall the cone with the spider and saddles into the dobro (leave the cover plate off), reinstall the strings, tune the instrument
and tighten the machine screw that connects the spider to the cone so that the sound and response is set to original levels. When this is done, remove the strings, set
the cone and spider assembly on your workbench and set the rest of the instrument aside.
Installing the Pickup Element
The RG-03 sensor is not meant to come into direct contact with any part of the cone. The putty that is supplied with the pickup acts as both a means of attachment
and as an isolator; there always has to be a bead of putty between the contacting surface of the sensor and the wall of the resonator cone. The sensor is meant to
contact the sidewall of the only.
1) Place the pickup on your workbench with the brass side facing up. From the supply of putty provided, run a single bead around the outside of the diameter of the
brass so that the putty covers only the colored potting material outboard of the brass. This bead should be about 1/4" in diameter. If possible, no putty should be on
the brass surface.
See fig 1
Note: On some cones, such as a Quaterman, the cone has a much steeper slope than is normal. In order for the pickup to not come into
direct contact with the cone, the putty must be moved further outboard than normal so that it is partly on the edge of the pickup and partly on the underside. See
illustrations below:
