If your amp makes no sound, it is first important to define what you mean by “no sound.” To that end, the first test you should perform is whether you can hear anything coming from the speakers. (This is, of course, after you have eliminated the possibility of trivial problems.)
Listening to what (if anything) comes out of the speakers can help you isolate the problem to specific parts of the circuit. If you hear no sound coming from the speakers — including hum, hiss, reverb crash, input cable pop, or any other incidental, non-musical sounds — the problem could be the speaker itself. But, if you hear non-audio sound coming from the speakers, the problem is
Audio amplifiers, and tube amplifiers in particular, contain high voltages. Do not attempt to repair an amplifier without following the appropriate safety protocols. This includes (but is not limited to) discharging the electrolytic capacitors if you are troubleshooting the circuit within the amp chassis. Note that electrolytic capacitors can pose a shock hazard even in the amp is turned off and unplugged.
Guitar Amps And Pa Systems For The Acoustic Guitarist
If there is absolutely nothing coming from the speakers, you should distinguish between an amplifier that is not turning on and an amplifier that is not passing signal. If you see tube glow and the pilot light is on, that is an indicator that the early power supply is functioning correctly (i.e., your amp turns on). If you don’t see these things, you should read the guide My amp doesn’t turn on first.
Usually, in a no-sound scenario, you will hear some sound coming from the speakers, even if the signal path happens to be cut off. For instance, you may hear hum, hiss, reverb crash (if applicable), or even popping sounds when connecting or disconnecting inputs. This is because, in many cases, the signal is interrupted well before the speaker, leaving the speaker to transmit any incidental noises that enter the circuit outside of the fault area.
However, it is certainly possible for the speaker to be interrupted in a way that also silences the speaker. Possible causes include:
Repairing A Standel Hybrid Amp
There might also be an interruption in the early power supply: for instance, a failing power transformer. These possibilities are discussed in the guide, My amp doesn’t turn on.
Listen to the speaker carefully, in a quiet room, to confirm that it is, indeed, not passing any signal whatsoever. Any audible signal, audio or otherwise, is a good clue. Give yourself every possible advantage when troubleshooting and always listen carefully before concluding that the speaker has no sound.
In some cases, the signal is extremely attenuated but very, very faintly audible. In this case, hum will also be attenuated, so you can’t necessarily make a determination of “no sound” by the absence of the usual noise floor. Turn the instrument up and make a thorough test before making your conclusions.
Common Home Theater Problems
When testing, make sure that the speaker is pointed in your general direction. You may need to get physically closer to the speaker than you would otherwise position it during normal use. This isn’t to suggest that you should smash your face against the speaker cloth for a closer listening experience: if there is an unexpected loud noise, you may damage your hearing. Just be aware of the position of the speaker. If it is on the floor, elevate it. If it is facing away from you, turn it around. If you can tilt it upwards, do so.
Is the speaker blown? Many symptoms of a blown speaker imitate symptoms of a malfunctioning amplifier. For this reason, you should always be suspicious of your speaker until you can prove that it is functioning correctly. One way to do this is to test the speaker in a working amplifier. You can always do the reverse — test a known working speaker in the questionable amplifier — but there is a chance that the amplifier is malfunctioning in a way that damaged the speaker in the first place. Shorted output transistors or a faulty output transformer can destroy a speaker in an instant. So, do not use a valuable speaker for this test.
If you hear hum, hiss, or other incidental sounds coming from the speakers, but no signal, there is probably some fault in the amplifier that is interrupting the signal. In this case, you can assume that your speakers are likely working. If your speakers are reproducing these incidental sounds, it would probably reproduce signal as well, if signal were present. The problem is that signal is not present. Where did it go?
Dvd Set Fix Repair Tube Guitar Amp Troubleshoot Valve Amplifier For El84 6l6
The bad news: a “no signal” problem can dwell anywhere in the amp circuit. The good news is that most problems can be narrowed down to small portions of the amplifier. In most cases, you don’t even need test equipment to determine where the problem is hiding. You can use your knowledge of how an amplifier works, along with the evidence that your malfunctioning amp is giving you.
Listen to the noise floor. The first piece of evidence that you have is the sound that the amplifier actually is making: the noise floor. We’re giving this section probably more real estate than it deserves, because listening to the noise floor is a vague and inexact method of diagnosing an amplifier’s problems. However, the point is that everything that the amp is doing should be treated as evidence of its malfunction. The more you listen to the amp and think about its issues, the less you’ll rip out and replace perfectly good components and drive yourself to total frustration.
Think of it this way: if you are the detective, the noise floor is the witness that says, “A guy wearing a green hat robbed me.” This is a great piece of information as long as you don’t forget that 1) a lot of people own green hats; 2) people have the ability to take their hats off, and/or put new hats on; 3) a lot of people don’t know what the color green is (Is chartreuse green? Is teal green?); 4) if the witness was dishonest or forgetful, there might not even be a green hat in the first place. So, you can’t simply arrest the first person you see who is wearing a green hat. In order to make sense of the green hat as evidence, you ideally need other information from other sources as well.
Bogen Db10 1 Mono Tube Power Amplifier, Needs Repair, No Sound Photo #2252592
Likewise, the noise floor is an unreliable witness. Although we can and should listen to it, we can’t let it dictate our method of troubleshooting. We can’t let it supersede our knowledge of the amplifier’s circuit or whatever other evidence the amp is offering. With that disclaimer out of the way, we’ll now discuss what to listen to when you listen to the noise floor.
When functioning correctly, every amplifier has a noise floor. So, if the noise floor coming from the speakers is identical or nearly identical to the amplifier’s usual noise floor, you can deduce that the amplifier is almost completely working correctly. The noise floor is present and it is thoroughly being amplified. Only the signal is absent. Therefore, you should start troubleshooting at the very beginning of the signal chain:
On the other hand, if the noise floor is lower than you would typically expect from this amplifier, it is likely that some of the amplifier’s hum is being interrupted, as well as the signal. This suggests a flaw or malfunction later in the preamp.
Vox Ad50vt Repair
Sometimes, the noise floor coming from the speaker is louder or more aggressive than the amp’s working noise floor. This suggests that a component is malfunctioning in a way that is not only interrupting the signal, but introducing noise itself. This often happens when an active component (i.e., a tube or a transistor) fails, but it could also happen due to the failure of a crucial passive component as well. The takeaway here is that you are probably not looking at a simple mis-wire, or corroded or damaged jack. Instead, there is probably a component that needs to be replaced. In a tube amp, replacing the tubes is a good place to start.
Bottom line: the noise floor is decent evidence, but it is important not to overstate the conclusions that you can draw from it. It’s not a form of code that, if cracked, will tell you exactly what your problem is. Rather, it will give you an idea of where to
— which is certainly a valuable tool, if you do not have an oscilloscope and nothing in the amplifier is obviously malfunctioning. However, if this beginning doesn’t solve your problem, you have to let go of this initial guess, circle back around and investigate some of the possibilities that you may have set aside as unlikely.
How To Repair Car Amplifier No Sound
Check all possible inputs and outputs. If the amplifier has two channels, try both. If neither channel gives you sound, the problem is likely somewhere in the circuit after the two channels merge. If one channel gives you sound, but not the other, the problem likely exists in the silent channel.
If the amplifier has an
0 Response to "Guitar Amp Repair No Sound"
Posting Komentar