Crate began manufacturing amplifiers in the late 1970s. The original Crate amplifier was a 10 watt solid state amp with one speaker enclosed in cabinet shaped like a wooden crate. Since that time, Crate amplifiers have become won a lot of respect and admiration in the guitar world. Crate produces a wide variety of amps ranging from budget-priced amps, high quality tube amps, solid state amps with digital effects, and acoustic amp designed to enhance acoustic instrument performance.
Read the manual for your Crate amplifier. The manual answers all of the essential questions about using the amp and it also provides troubleshooting advice that addresses specific problems that you may encounter. Amplifier manuals for contemporary Crate amps are available as downloads at the Crate website. If you need to find a manual for an older Crate model call 1-800-738-7563 or 314-569-0141.
Check the power supply if the Crate amp does not turn on. Make sure that the amp is plugged in and that the power source is alive. It is not unusual for one side of the stage to have power and the opposite side to not have power. If you are plugged into a power strip, double-check to see if the power strip is in the On position
Inspect and replace the fuse if the power source is good but the amplifier won't come on. Refer to the manual if you cannot locate the fuse on your amp. The fuses are typically on the back of the amplifier. Replace it with the same type of fuse The fuse is a safety feature that protects the amp. A blown fuse indicates that the amp may have a more serious problem.
Inspect all the guitar cables and effects pedals if the amp is on but produces no sound. A loose or bad guitar cable prevents the electric signal from reaching the amplifier. A non-functioning effect pedal also interrupts the signal. The potential for a loose or bad cable increases when you use effects pedals because each pedal has to be plugged in. Bypass the pedals and plug directly into the amplifier. If this fixes the problem, unplug and plug in each of the other cables. Step on each pedal individually and look at the LED light to make sure that has power. A dim LED light indicates a weak battery.
Spray the posts with contact cleaner if the knobs are making scratchy or hissing sounds. Remove the knobs from the amp and spray the posts with contact cleaner to remove dust, dirt and other debris. Turn the knobs all the way to the left and to the right several times. This is a time-consuming process because some Crate amps, such as the Acoustic models, have so many knobs.
Inspect the tubes if your Crate is a tube amplifier and the sound is weak or muddy. Low volume problems in a tube amplifier or muddy and distorted tone is usually caused by weak tubes. Healthy tubes emit a warm orange/amber glow. Weak tubes emit a purple/bluish glow. If it is difficult to identify the problem, turn the amp off and allow the tubes to cool down. Replace one tube at a time. Turn the amp on and see if the problem has been corrected.
Examine the speakers in the amplifier. Bad or damaged speakers cause a number of problems such as intermittent sound, distorted sound, and muddy tones. Remove the grille or panel on your amp with a screwdriver and examine the speakers and speaker wires. Each speaker is connected to the amp with a negative and positive speaker wire. Make sure the wires are firmly connected to the rear of the speakers. Shine a flashlight on the speaker cone and examine it for rips or tears. Speaker cones damage is easily repaired with tape or glue. A blown speaker, where the cone and coil separate, needs to be replaced.
Set all the knobs at 12 o'clock for each channel. Use this setting as a starting point. Setting the tone and volume controls for multiple channels is somewhat confusing at first if you are more accustomed to Fender style amps where you have three to four knobs to worry about. Crate acoustic amp, for example, have a variety of controls for fighting feedback such as the active/piezo switch, the "frequency" and "cut" filters, and the EQ level controls. If you are playing an acoustic guitar with a piezo pickup, the piezo option must be engaged on the amp. Manipulating the frequency and cut knobs fine tunes the feedback control on the amp.