TROUBLE-SHOOTING GUIDE
If at any time your SFS-40 amplifier fails to work, follow this simple checklist:
1. Make certain that the A.C. power cord is plugged in firmly at the A.C. wall socket.
2. Make sure that you have biased the output tubes.
3. Open the fuseholder. Check that:
A.
A “slo-blo” fuse, with a rating of 2 1/2 Amp 250V (0.25” x 1.25”), is installed (or
1 1/4 Amp 250V (5mm x 20mm) for European and Asian versions).
B.
That the A.C. power fuse is intact and has not blown.
4. If the power line fuse has blown, replace it with a same size and type fuse of the same rating
(2 1/2 Amp 250V. slo-blo - 100 to 120 Volt Countries / 1 1/4 Amp 250V. - 200 to 240 Volt
Countries).
5. Turn on the amplifier. If the amplifier fails to operate, turn off the amplifier, remove the four
EL34/E34L power tubes (using a glove, cloth or paper towel) and turn the amp on again. If the
four small 6DJ8 type tubes glow and the A.C. line fuse remains intact, it is likely that one of the
four power tubes has shorted and should be replaced.
6. If the fuse blows again without the power tubes installed, then you should return the
amplifier to your dealer or to a service depot for repair.
NOTE:
Under no circumstances should you replace the A.C. power fuse with one of a higher
current rating! Doing so may cause further damage to the amplifier in the event of a
fault condition and will also void your warranty! In addition, your continued protection
from the risk of fire or shock would be seriously compromised.
NOTE:
The surge capabilities of slo-blo fuses from different manufacturers vary. If in doubt,
replace your fuse with one supplied by SONIC FRONTIERS or your distributor.
7. If at anytime you are unable to adjust the meter pointer to read at least “35” on the meter, for
any one of the four power tubes, you should replace the tube as it is nearing the end of its useful
life.
8. If you experience a slight “HUM” in your system, you may have a “Ground Loop.” This is
caused by having more than one grounded component in your system when all these components
run off the same AC circuit. To eliminate this problem, “lift the ground” (either remove the ground
prong off your AC cord or use a 3-to-2 adapter plug) on one of the components, preferably a source
component such as a Preamplifier. If you are still unsure, please contact your dealer for further
assistance.
