Cleaning and adjusting on volume potentiometer believe is that we would like to know the problem, because there are three adjustable potentiometer terminals, the resistance of the resistance element can be some variation regulation. Usually adjustable by a resistor and a movable brush composition potentiometer. When moving the brush along the resistor at the output of that is to get a certain amount of displacement of the relationship between the resistance value or voltage. Adjustable potentiometer can also use as a three-terminal device can be used for two-terminal element to use. The latter may be regarded as a variable resistor. Poor contact between the film need to be cleansed of impurities between them.
　　1, tools: syringes and a high concentration of alcohol. In fact, the syringe is best to use 5mL specifications
　　2, the operation: very simple, alcohol extracted with a syringe, injected from the pin direction potentiometer, rotary potentiometer then repeated many times, the last with a hair dryer, while rotating the potentiometer, while drying it. Note that there are two potentiometers, one tube volume, the other is a tube tone.
　　Mount on playing, in fact, bought back in soon after the speaker has been completed. In the overall balance of principle, just for a simple change. Some other more advanced transformation beating, as replaced by more advanced op amps, the E-type transformers replaced with more powerful toroidal transformer to add servo amplifier and power supply voltage, until the speakers are replaced this, then, might as well buy one pair of speakers is more expensive and more advanced calculations.
　　1, to increase the power filtering high frequency decoupling capacitors to improve the treble effect. This is in fact the power supply filter capacitor (25V, 2200μF) the feet parallel on a 0.1μF small capacitor.
　　2, the original operational amplifier (preamplifier) ​​4558 into better sound quality NE5532. To sound interested friends should know, I remember when this piece of 5532 branded the "op amp of the Emperor" reputation.
　　3, increase the heat dissipation area, the benefits of the Earth people know.
　　4, and increase the power supply filter capacitor, the original filter capacitor is 2200μF can be replaced or 3300μF 4700μF can be improved to a certain extent, enhance the bass effect.
　　5, will treble the original crossover capacitance electrolytic capacitors replaced with the capacity of polyester capacitors or dedicated audio capacitors to improve the treble sound quality is also good. And a pair of coupling electrolytic capacitors on the audio path, they can also be upgraded, the role is quite obvious.
　　I believe that if read adjustable potentiometer cleaning and adjustment narrative should be able to move their own hands and to wash their own adjustment potentiometer the sound. If you can find it useful to share and forward it to their friends Oh!