How to adjust the reverb of the amplifier
Generally speaking, reverberation is echo rather than real reverberation. Due to room size, volume level, acoustic environment, male and female voices, there is no fixed tone. 1. For conference sound reinforcement, you should turn off or turn down the echo, adjust the bass properly, and open the middle and high tones. 2. For karaoke, you should properly turn on the large echo (about 0.6 seconds), adjust the bass loudly, and slightly adjust the middle and high notes. How to adjust the reverb of the amplifier How to repair the low power amplifier 1: Check whether the input jack of the power amplifier is intact and whether there is bad contact. 2: Check whether the volume potentiometer is intact, whether the resistance value deviates large, especially large, you can use advanced special potentiometer cleaner to clean it, most of them can return to normal. 3: Check the negative feedback loop of the power amplifier, and focus on the negative feedback resistor and capacitor (some electrolytic electricity is easy to cause problems). 4: Check whether the resistance between the output relay contact and the rear contact is too large. If the contact is severely oxidized, the output will be very small. Replace the relay. 5: Check whether the working point of the amplifier is completely normal. 6: If there is an oscilloscope, it will be simple if the power amplifier output sound is small. How to adjust the reverb of the amplifier How to solve the problem of no sound output from the power amplifier If you have a power amplifier at home, it will be clearer. Some problems, large and small, will appear during use. For example, there is no sound output from the power amplifier. Do you know how to solve it? Although it is a sound problem, it is not so simple to overhaul. The following is an analysis of this phenomenon. You can refer to it and see if you can deal with it next time. Amplifier output without sound troubleshooting: 1. When operating each function key, there is a corresponding status display, but no signal output. When overhauling an amplifier with a protection circuit, you should see whether the protection relay can be closed after starting. 2. If the relay does not operate, it is necessary to measure whether the output voltage of the midpoint of the power amplifier circuit is shifted and whether the overcurrent detection voltage is normal. 3. If the midpoint output voltage offset or overcurrent detection voltage is abnormal, it is a problem with the power amplifier circuit, and then it is necessary to check whether the positive and negative power supplies are normal. 4. If the positive and negative voltages are asymmetric, the load circuits of the positive and negative power supplies can be disconnected to determine whether the power supply circuit itself is abnormal or the power amplifier circuit is faulty. 5. If the positive and negative power supplies are normal, check whether the amplifier tubes in the power amplifier circuit are damaged. 6. If the output voltage of the midpoint of the power amplifier circuit and the overcurrent detection voltage are normal, and the maintenance relay does not pull in, then the fault is in the maintenance circuit. You should check the relay drive IC or drive tube for damage and whether each detection circuit is normal. 7. If the relay contacts can be closed, but there is no sound output, you should first check whether the speaker is normal, whether the relay contacts are in good contact, and whether the noise suppression circuit is operating. 8. If the above parts are normal, then use the signal interference method to check whether the fault is in the power amplifier's rear stage or pre-stage circuit. Use the R × 1 block of the multimeter to connect the red test lead to the ground, and the black test pen quickly touches the input end of the rear-stage expansion circuit. If there is a strong “click” sound in the speaker, the problem is in the front-stage expansion circuit; if the speaker does not respond , The problem is to expand the circuit in the latter stage. For the integrated circuit power amplifier circuit (usually with thermal protection inside the integrated circuit) that does not select the peripheral maintenance circuit, you can first measure whether the power supply voltage is normal or not. 9. If the power supply voltage is normal, then use the signal interference method to check: participate in the DC intermittent signal at the signal input end of the power amplifier integrated circuit. If the speaker has a strong 'click' sound, it indicates that the power amplifier integrated circuit is normal, and the fault is at the front level Expand the circuit; if there is no 'click' sound, and the related peripheral components are normal, the fault is in the power amplifier integrated circuit itself. 10. If the tube amplifier has no sound output, you should also check its power supply to see if the filament is on and the temperature of the tube is normal. If the filament is not bright, the tube is very cold, you should check whether the voltage of the filament and the screen of the power amplifier is normal. If the voltage is not normal, check the power circuit further, and if necessary, disconnect the power load circuit to determine whether the power circuit is defective or the load has a short circuit. 11. If the voltages are normal, you can participate in the DC intermittent disturbance signal at the center of the volume potentiometer. If there is a strong reverberation, it is stated that the rear-stage expansion circuit is normal, and the fault is in the front-stage expansion circuit; otherwise, the fault is in the rear-stage expansion circuit . You can participate in the scramble signal at the grid of the pusher tube and the grid of the input expansion tube respectively. At which level the scramble signal is added, there is no response, which clarifies that the circuit behind this level is not working properly. 12. The suspicious components (such as electron tubes) can be replaced by the replacement method. AV amplifier with Dolby surround sound decoding function, if all channels are silent in the Dolby surround sound condition and the main channel sound is normal under the through condition, when the power supply circuit is normal, usually Dolby surround sound decoding The operation of the circuit or system control circuit is abnormal. If there is no sound in all channels in surround sound and through mode, you should check the system control circuit, signal selection circuit and total volume control circuit.