Page 4 of 9
Section 2: Installing the Kit
Dealing with Metal Shavings
Installing the volume control requires that you drill a hole in the front panel of the GT-
102. If you’re installing the volume control into an already built GT-102, then you must
be very careful that the metal shavings resulting from drilling the hole don’t short out the
electronics already installed in the enclosure. We’ll show some ways to avoid problems
with metal shavings shortly.
The best time to make the hole for the volume control is before you’ve installed any
electronics in the chassis. It’s then easy to clean up the metal shavings without any
special tools or precautions. No matter when the hole is drilled, the metal shavings must
be removed.
Figure 1 – Location of the Volume Control hole
Locating the hole
Figure 1 shows the hole placement. To locate the hole without damaging the paint, we
recommend that you measure the rough position of where the hole will go, then cover the
location with a piece of painter’s masking tape. Now you can accurately measure and
mark the hole location on the masking tape with a pen or pencil. This protects the finish
from damage.
Make a catch basin out of duct tape. You’ll place this catch basin on the inside of the
chassis front wall, behind where the hole will be drilled. The purpose of the duct-tape
catch-basin is to catch the metal filings before they can get away from you. This is
particularly important if the amp is already built. It’s not quite so important if you’re
putting the hole in an empty chassis. In either case, your goal is to end up with no stray
metal chips in the chassis.
To accurately locate the hole, use a spring-loaded center-punch, If you don’t have one, a
nail and a tap of a hammer will mark an indentation to guide your drill bit.
Start with a small drill and make a small hole, say 1/16”. Change to a 1/8” drill and
enlarge the hole. Before making the hole any larger, make sure that the chassis is secured.
Change to a ¼” drill and enlarge the hole again. Don’t press too hard. Let the drill do the
