Caution

Read these instructions completely before beginning the installation. The anr modules are finely tuned & require that installation be performed strictly in accordance with this manual. Deviations from the instructions contained herein will result in a system malfunction. Purchaser assumes all risks arising from an improper installation.

This product is intended for "self" installation into your headset and requires reasonable skill in the use of a soldering tool but a minimal understanding of electronics. If you question your ability to perform the installation, you are advised to take this unit & your headset to the nearest electronic technician, or ship them to HEADSETS, INC. for a factory installation. Any competent radio/tv technician or avionics technician should be able to install the modules in less than 2 hours.

Parts List

Check to see you have received all materials

1 pair modules (2 modules) - marked R & L. Each module contains an anr speaker, audio speaker, microphone and circuit board.

1 battery case - Sliding door permits easy access to the 9v battery.

1 power cable - 60 inch, 2 conductor (red = 9v+ black or white = ground-).

1 crossover cable - a 4 conductor cable, 33" length.

1 zip-loc bag of installation materials: solder, 28 ga wire, shrink-wrap, rubber grommet, tie-wraps, strips of double sided adhesive tape, 2 fabric pads (black/white oval), 4 pieces of temperfoam insulation (4 pink crescent shaped pieces).

1. Fine tip soldering tool (20 watt or less)

2. Power drill and 1/8", 3/16" and 1/4" bits

3. Small wire cutters

4. Small screwdriver set

5. Damp sponge- to clean solder tip

6. Butane lighter-to heat shrink wrap

7. Continuity Tester (optional)-very helpful to confirm & identify wire leads

I. Remove existing speakers

Remove the earseals from each earcup & place them out of the way to avoid burning them with a hot soldering iron. The earseals stretch around the earcup flange & are easy to remove.

Inside each earcup, surrounding the speaker, you will find 2 or 3 pieces of foam packing. Use tweasers to remove the top piece of foam (usually donut shaped). You will see 2 screws which hold each speaker in place. Remove the 2 screws. The speakers can now be lifted from the earcups. Disconnect the 2 speaker wires from the speaker.

Identify & mark these 2 wires audio+ and audio-. In 98% of headsets the wire passing through the volume control will be the audio (+). The other wire is, of course, the audio (-) [exception: Flightcom 4DX and 5DX sets, see special instructions] If you have any doubt about the identity of audio+ and audio- you should use a continuity tester (circuit tester) and refer to the drawing of audio plugs above color drawing A.

Remove all but the deepest piece of the original foam insulation. Be careful of the volume control terminals. The terminals can be very brittle on David Clark models, so avoid bending. Leave the earcups empty while splicing the wiring. The new pink insulation pieces will be installed after the wiring job is complete.

Insert a module into each earcup to insure that a fit can be made. Generally, any make of headset which is similar to the David Clark "H-10 series" will accept the anr module. David Clark model H-10-13.4 has earcups which are shallower than most & left side requires extra attention to tucking wires away when finally closing L earcup. Headsets with PTT (push to talk) switch in right earcup must be disabled, but the push button switch may be left in place if clearance is not a problem.

IMPORTANT: it is mandatory that you use "silicone gel" type earseals. The original earseals (dry or liquid filled) are not as airtight as gel seals, and in addition do not dampen sound & vibration as effectively. The result is that the anr units will greatly underperform (20-50%) & will be more likely to malfunction. The only earseals compatible with the anr modules are the David Clark gel ear seals , the AvComm gel ear seals or the FlightCom gel-flo ear seals. We stock the AvComm earseal ($25).

II. Install power cable

Using a pen or marker, mark a point at the base of the left earcup to drill a 1/4 inch hole to permit the power cable to enter the left earcup.

1. Don't drill the hole at the very bottom of the earcup, because the wall thickness here can reach almost 1/4 inch, which is too thick for the grommet we provide. Locate the hole in a position similar to the location of the grommet for the cable going to the boom mic.

2. Check inside the earcup to be sure you are not going to hit an obstruction (i.e., the post where original speaker was mounted).

3. Drill a 1/8" pilot hole, then enlarge to 3/16", and then 1/4". Carefully de-burr the edges of the hole with a small knife. Remove all debris. Install the rubber grommet, making sure it is fully seated inside the earcup.

4. Feed the power cable through the grommet and place a tie wrap on the cable about 3 inches from the upper end of the cable to prevent it from being pulled out. Remove the outer insulation (black casing) above the tie wrap. Next, remove/cut the shield (bare wire) from the cable. Pull down on the cable to seat the tie-wrap, pulling slowly so you don't unseat the grommet.

5. After the power cable is installed, attach it to the main cable using the black 3" tie-wraps. Place a tie-wrap every 10 inches along the cables. Trim off the excess tie-wrap length. The 2 cables will quickly tangle if they are not bundled together.

III. Install new crossover cable

The crossover cable is the cable that runs overhead from your left earcup to your right earcup.

For David Clark model H10-50 or -60, AvComm AC-800 or -900, or Softcom model C-60 call us for technical assistance prior to removing original crossover cable.

The original cable probably has only 2 leads and no shield. If so, it must be replaced with the 4 conductor cable provided. Using wire cutters, remove your existing cable and replace it with the new crossover cable provided. The new cable should easily slide through and replace the old cable.

OPTION: If your crossover cable has 2 leads and a bare shield, you may opt to re-use it by using the shield as a 3rd conductor. To use the shield as a 3^rd conductor, solder a 3" length of the 28 ga wire (provided) to each end of the shield. IMPORTANT: Avoid loose strands of wire. Cover the splice with shrink wrap & heat gently.

With this option:

1. Only use the shield for the common ground (i.e., don't use shield for 9v+ or audio+).

2. Be sure to disconnect the crossover cable shield from the remainder of the shield system (notice the shields for the mic, audio, & crossover cable all connect together in the L earcup).

Some installations require a 4 conductor crossover cable. This of course requires using the new crossover cable provided. These include any headset which has a single volume control located in the right earcup (e.g. all Sigtronics models, Dave Clark H10-60). Figure "C" on the color diagram shows the layout for this arrangement.

IV. Review the color wiring diagram

Refer to Figure A on the color wiring diagram and to Figure 3 at right.

1. Although most installations will follow Figures A and 3, there are 4 other color diagrams showing the correct method to wire various headsets (see fig. B, C, D & E). Choose the one that matches your headset type (i.e., stereo or mono; location and number of volume controls).

2. The only two wires you must identify are audio+ and audio-. These were the two wires attached to the original audio speakers and should have been marked when the speakers were removed. If you're not certain which is audio+ and which is audio-, use a continuity tester and refer to the drawing of audio plugs located directly above figure A. The color wiring diagram represents the wiring to be installed, and cannot be used to identify the original audio (+) and audio (-) wires found in your headset.

3. Determine whether your headset is mono or stereo by comparing your audio plug to the plugs pictured on the color wiring diagram.

If your headset is mono, the audio+ usually passes through the volume control as per color diagram "A". The ground- wire will usually be black or white. Identity can easily be confirmed with a continuity tester applied to the audio plug and the unknown wire. The tip of the audio plug is always audio (+). The base of the audio plug is always audio (-).

If your headset is stereo, audio+ will consist of 2 leads, each passing through its own volume control, as shown in Fig. D.

V. About soldering

If you are not experienced with a fine tip soldering tool, a few minutes of practice will greatly improve your proficiency. Spend enough time and care to insure that solder joints and splices are cleanly done.

When soldering 2 wires together, twist the bare wire strands and trim to leave only 1/8" bare wire exposed. Heat the bare wire ends with iron and "tin" wire ends by melting solder into the wire until it is "wet" with solder. The rosin core of the solder acts to facilitate the wetting of the wire braid, so melt the solder directly into the wire to be tinned, and also to the tip of the (clean) tool. Clean the solder tool tip of excess solder & rosin by rubbing it on a damp sponge or towel.

Wire ends being soldered should each have only 1/8" to 1/4" exposed.

Cover the exposed splice with shrink wrap. Heat the shrink wrap for 1-2 seconds with a flame (butane lighter works best). Keep the flame away from the wrap to avoid burning it.

Use only the 28 ga. wire provided when constructing the wiring harness and attaching to the p.c. board. Do not use heavier gage wire from the original headset or the final installation will be more difficult (i.e., tucking wires & closing unit). Using the flexible 28 ga. wire (and removing excess lengths of original wire) will result in a more professional installation.

Use only electronic type solder (has no acid). A fine point soldering iron is available at most hardware stores for under $10. Practice soldering. Re-work any splices if not pleased with initial work, or if you see that the wiring job can be improved.

All of the splicing takes place in the left earcup. In the right earcup the soldering only involves attaching 3 leads of the crossover cable to the module's printed circuit board. Don't solder any wires directly to the module's printed circuit boards until the wiring harness is complete and the headset is ready to close (step VII).

A. Audio cable leads: the original audio cable enters the left earcup. It carries at least 4 conductors: 1. audio+ 2. audio- 3. mic+ 4. mic-

1. audio(+) wire is the wire that passes through the volume control, thereafter dividing into 2 wires to form R & L audio+. Attach one of these 2 to the crossover cable/green wire. Let the other hang loose in the left earcup. Each earcup now has 1 green wire to attach to a module in step VII.

2. audio(-) wire should be tied in with the 9v(-) wire to form a common ground (also described in #2 below). This common ground wire should now be spliced into 2 black wires and one of these 2 should attach to the crossover cable/black wire. Let the other hang loose in the left earcup. Each earcup now has 1 black wire to attach to a module in step VII.

3. & 4. mic+ and mic- wires can be identified by tracing them to & from the boom mic. Do not tie into the mic circuit in any manner.

B. Power cable leads: the new power cable you installed has 2 wires:

1. Red wire: 9v+ should be spliced into 2 red wires, per the color diagram. One will then attach to the crossover cable/red wire. Let the other red wire hang loose in the left earcup. Each earcup now has 1 red wire to attach to a module in step VII.

2. Black or white wire: As stated above the 9v- wire and the audio- wire must be soldered together in order to create a common ground. After 9v- and audio- merge into one, the common ground they form should then be divided (spliced) into 2 leads. Attach one of these to the crossover cable/black. Let the other hang loose in the left earcup. Each earcup now has one common ground wire to attach to a module in step VII.

VII. Insulate Wire to modules Close headset

Installing Temperfoam Insulation

Before soldering any wiring to the modules, install the insulation provided. The pink crescent shaped pieces of insulation should be tucked under the edge of the earcup, so that the notch on the inside edge of the crescent shaped pieces are at the 9 o'clock and 3 o'clock positions. Bring the 3 wire leads out through the center of the donut.

Attach wiring to modules

Melt a small spot of solder onto each of the 3 "thru-hole" attach points on each module's circuit board. Carefully solder the 3 wires to each of the circuit boards according to the color diagram. If you wear your boom mic on your left, install the L module into that earcup. If you wear your boom mic on your right, install the R module in to that earcup (see operating instructions, #2).

Close Headset

The installation materials contain strips of 2 sided adhesive (.25" x 3.00"). Cut these strips in half to make 4 pieces (.25" x 1.50"). Apply tape as shown below (Fig. 5), leaving exposed backing paper in place until reading the following:

Arrange the wiring as neatly as possible. Tuck wiring away where possible. Compress the pink insulation under the edge of the earcup and fit the modules into the earcups. They should fit well & not tend to push out more than 1/8" (gap between the flange of the module and earcup).

You may want to test the headset before bonding modules into earcups. Insert modules into earcups (prior to removing backing paper from adhesive) and install earseals. Be sure that black/white pad is in place before testing. When audio system and anr system work properly, remove earseals and withdraw module only enough to allow removal of exposed backing paper from tape. If module is removed from earcup, check to see that wiring, etc., remains tucked out of the way. Press module firmly into earcup.

If it is necessary to remove module after final installation, take care not to damage module during removal. Do not pry module from earcup. Removal is accomplished by inserting knife blade between module and earcup. This will deform the tape, separating earcup and module without damage. This adhesive tape is semi-permanent and may need to be replaced if module is removed from earcup. We can provide additional tape free of charge.