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發表於 2014-4-17 17:49:37
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How would I describe Class A amp in general?..Hmm...Technically, if we connect a scope and observe a static sine wave, a good Class A's out-put looks like a sine waves. No ripple, no cross-over distortions. One problem is that it does have higher lower harmonic distortions, mainly second and/or third harmonics. In more complex dynamic wave reproductions. It is the next best thing can happen comparing to the original signal. It is "on" at all time. Therefore, there is no switch what what so ever, unlike ALL other classes that has switches somewhere. Meaning that is ready to work at all times without any delays.
In real life experience, Class A amp with JFET front end it is the best it can be. Very tube like sounding at mid range, especially for vocals and strings. It is second to none. Very airy, good details. Bass could be a bit of the issue depending on how well build the amp is since lower range consumes the most power. Not every Class A is good and a good Class A amp is very very costly. A well build Class A designed by a musician/singer is impossible to find if cost is a factor. Of course, big electricity bill too..
My humble opinion and 2 cents. Hope such general/short descriptions might help our members to visualize why class A still exist. The oldest amp design in the world.
補充內容 (2014-4-17 18:10):
The production of JFET is limited because of Sony and Yamaha. The VFET's production is zero for years. Sad news to the Hi Fi industry. |
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