Operation
The SA-3 was designed to handle a wide range of listening levels, but every component has limits. It is important to use common sense and listen for signs of possible distress from the subwoofer. Noticeable distortion or harsh breakup is an indication that either the SA-3 or the subwoofer is running beyond its capacity, and the volume should be decreased. If you feel heat emanating from the front of the woofer, reduce the level immediately. Speaker damage most often occurs from sustained high volume levels, not from transient sounds or brief musical peaks. Excessive boosting of bass, treble, or equalizer controls can worsen the problem and is not recommended.
Maintenance
Your SA-3 subwoofer amplifier has been designed for years of trouble-free operation and required minimal maintenance under normal use. The SA-3 may be cleaned by wiping with a lint-free cloth. Do not expose the SA-3 to direct sunlight, high temperatures or moisture. In the event that service is required, do not open the SA-3. Refer the unit to a qualified service technician.
Changing the Line Voltage Setting
In the event that it is necessary to change the line voltage setting, begin by turning the power switch to the OFF position. Remove all connections from the subwoofer, including the detachable power cord. Locate the two screws holding the cover plate over the volt- age selector switch, and loosen both screws two turns. DO NOT REMOVE THE SCREWS! Rotate the cover plate 45 degrees to gain access to the switch. Using a flat blade screwdriver, slide the switch to the correct position. Use the 115 VAC position for 110 to 120 VAC, and the 230 VAC position for 220 to 240 VAC. Slide the cover plate back into position. Tighten both screws. Next, you will need to replace the fuse (see “Changing the Fuse”).
Changing the Fuse
Always replace the fuse with one of the exact same specifications. For systems operating in the 115 volt setting, use only 5 x 20 mm, T4A, 250-volt slow-blow fuses. For systems operating in the 230 volt setting, use only 5 x 20 mm, T2A, 250-volt slow-blow fuses.
The SA-3 subwoofer amplifier has a user-serviceable fuse. To replace or change the fuse, begin by turning the power to the OFF position and removing the detachable power cord from the amplifier. Next, remove the fuse holder cover from the power cord socket with a flat blade screwdriver. Remove the fuse from the holder and replace it with the appropriate type. For 110 to 120 VAC, use a 5mm x 20mm T4A 250V slow-blow fuse. For 220 to 240 VAC, use a 5mm x 20mm T2A 250V slow-blow fuse. Reinstall the fuse holder. Replace the power cord with the appropriate type designed for your wall outlet. Reconnect the power cord.
Troubleshooting
If the amplifier fails to operate when the Power Switch is turned on, check the power cord and all the input and output connections thoroughly. If the front panel status LED is red, the unit is in “protect” mode. This could be caused by incorrect wiring, short circuits, or excessive volume. Turn off the Power Switch on the front panel for two or more seconds to reset. Double check all speaker cables to be sure that no small strands are extruding. If the front panel LED indicator fails to illuminate, it is possible that mis-wiring or an electrical power surge has caused the protection fuse to blow. It must be replaced with one of correct type and value. Contact your local Authorized NHT Dealer or NHT immediately for assistance.
