Electrolytic Capacitors
The only other maintenance task that is likely to come up might be changing the
electrolytic capacitors. Electrolytic capacitors contain a dielectric gel that can dry
out over time and compromise the performance of the capacitor. In general, this
takes a
very long time
to happen, if it happens at all. With modern, highquality
parts, like those used in the D
₂
O Amplifier, we're probably talking something on
the order of 20 years or so. This task must be performed by a qualified repair
technician.
Troubleshooting
We've tried to think of some scenarios you might encounter and how you might
go about troubleshooting them.
The amp does not power on.
Hopefully you've checked to make sure it is plugged in. If it is plugged into a
surge protector you've made sure that that surge protector is plugged in and is
turned on. Check the fuse.
Make sure the amplifier is turned off before
checking the fuse.
Remove the fuse from the fuse holder and examine the fuse
visually. Usually, if the fuse has burnt out you will see some black char inside the
glass envelope, and you'll see that the filament is no longer continuous from one
end of the fuse to the other. If you have a multimeter you can check for electrical
continuity across the fuse. Replace the fuse with the proper type of fuse. See the
above section on replacing the fuse. If the amp still does not power on or if a new
fuse burns out, your amp will need to be seen by a qualified repair technician.
The amp powers on but no sound comes from the speaker.
When you turn the volume up all the way, do you hear any hiss coming from the
speaker? If yes, then the power amplifier is working and you have a solid
connection to the speaker cabinet. (Turn the amp to your normal usable level.)
Check to make sure you're actually getting a signal at the input. If you have any
effects between your instrument and the amplifier, try removing them from the
signal chain and plugging your instrument directly into the input of the amplifier.
If there is still no sound, make sure the volume control is up on your instrument.
Try swapping out the instrument cable to see if that makes a difference. If you
have another amplifier, try plugging your instrument into that to see if there is a
problem with the instrument.
If there is no hiss coming from the speaker cabinet with the volume all the way
up, then there is a problem with amplifier, the amplifier's connection to the