Instructions for Making an ME3 Modification Jig:

For those with a little time on a Saturday afternoon and a few basic tools, this is a relatively simple device to make and ideally can be completed in a hour or so, save finishing time should you decide to put a coat of water based polyurythane or other protective finish on the device. It can be made of any wood, although a hardwood is preferred, especially if you intend to use this repeatedly. Should you decide to construct this with more commonly available 1 1/2 thick stock, the middle hole should extend to within 1/4 inch of the bottom rather than 1/2 inch.

Basic supplies:

• Saw (ideally a table saw)
• Drill (easier with a drill press, but feasible with portable electric drill that can handle needed bits)
• Drill bits: 9/64", 21/64", and 25/64" (can substitue 3/8 inch for 25/64)
• Block of wood about 4"x4"x1 3/4", ideally hardwood
• Nylon 3/8  x 3 inch hex bolt (available from Home Depot or hardware store)
• Optional:  finishing materials, felt for bottom

Schematic View of Jig:

General steps in Construction:

1.  From stock wood, ideally a hardwood such as cherry, maple, oak, etc., cut the basic block to an approximate 4 inch length and width (figure 1)

2.  Optionally cut off the corners at a 45 degree angle and in about ¾ inch (Figure 2)

3.  Measure the location for the hole.  This should be in at least an inch and cut be as far in as the center of the wooden block (Figure 3)

4.  Drill an initial hole 9/64 inch through the entire block (Figure 4)

5.  Drill the next hole 21/64 inch through the initial hole but through all but the bottom ½ inch of the bock (Figure 5)

6.  Drill the final hole using a 25/64 (alternatively a 3/8 for a slightly snugger fit) drill bit down about ½ from the top of the block (Figure 6)

7.  Using a saw cut a channel about 1/8 through the font of the block, so that it meets the initial small hole. (Figure 7)

8.  Sand and finish the block as desired (the completed block prior to finishing is shown in figure 8; a cutaway showing how the Sennheiser plug inserts into the 3 holes is shown in Figure 9)

9.  Optionally, glue felt to the bottom of the bock, using wood glue and trimming off the edges with a straight edge and single edged razor.

10.  Prepare the driving bolt by cutting off the threaded portion with a fine toothed saw such as a hack saw (Figures 11, 12)

11.  After smoothing the end of the driving bolt with some sandpaper, mark and make a small nick in the exact center using an awl or nail (Figure 13)

12.  Drill a hole about ¾ inch down the center of the driving bolt using a 9/64 inch drill (Figure 14)

13.  Smooth the edges of the driving bolt as needed with some fine sandpaper.

Once the entire jig is done, the actual Sennheiser ME 3 modification is described in detail here.

Figures:

Figure 1:  The completed block about 4 inch x 4 inch x 1 ¾ inch

 

Figure 2:  Optional removal of corners.

 

Figure 3:  Measure spot for hole, generally in center of block in one dimention and about 1 ½ in from the edge.

 

Figure 4:  Drill initial 9/64 hole entirely through block.

 

Figure 5:  Second hole with 21/64 inch bit should stop about ½ inch from the bottom of the block.

 

Figure 6:  Final 25/64 inch (or3/8) hole should extend down only about ½ inch.

 

Figure 7:  Use table saw or other saw to make slot extending all the way to center of initial hole.

 

Figure 8:  Appearance of completed block (prior to sanding, finishing, etc.)

 

 

Figure 9: Cutaway view showing how the Sennheiser ME3 plug inserts into the hole. When using the jig, the cord does not exit the bottom of the hole, but rather through the slot as it extends in from the side of the jig. The majority of the force when tapping down the locking ring is absorbed by the end of the thicked part of the jack as it merges with the wire. The remainder of the jig opening simply support the jack.

 

 

Figure 10:  Needed 3/8 inch x 3 inch nylon hex bolt

 

 

Figure 11:  Cutting off threaded portion of nylon hex bolt with hack saw.

 

Figure 12:  Marking and nicking center of hex bolt prior to drilling

 

Figure 13:  Drilling 9/64 inch hole about ¾ inch down center of nylon hex bolt

That's it! A few of these steps can be eliminated and all of this can be done (albeit with more difficulty) without the use of power tools. If you have any questions please feel free to email us.