放(fang)(fang)大器(qi)的尺寸和形狀有很多種，它(ta)(ta)們(men)(men)的設計(ji)用(yong)(yong)(yong)途是不計(ji)其(qi)數(shu)的，它(ta)(ta)們(men)(men)基本上(shang)都是一(yi)樣的：它(ta)(ta)們(men)(men)處(chu)理聲(sheng)(sheng)(sheng)音信號，并通過(guo)揚聲(sheng)(sheng)(sheng)器(qi)使(shi)聲(sheng)(sheng)(sheng)音變得更大。雖然大多數(shu)放(fang)(fang)大器(qi)都相(xiang)當大，以(yi)便處(chu)理具有大量功率和放(fang)(fang)大效果(guo)的聲(sheng)(sheng)(sheng)音，有些(xie)放(fang)(fang)大器(qi)非常小且(qie)緊(jin)湊。小型(xing)放(fang)(fang)大器(qi)足(zu)夠小，既便于(yu)攜帶又緊(jin)湊，同時還允許在某些(xie)設置下使(shi)用(yong)(yong)(yong)足(zu)夠的放(fang)(fang)大效果(guo)。微(wei)型(xing)放(fang)(fang)大器(qi)非常便攜，并且(qie)可用(yong)(yong)(yong)于(yu)需(xu)要更安(an)靜(jing)的放(fang)(fang)大系統的場合。迷你放(fang)(fang)大器(qi)特(te)別適用(yong)(yong)(yong)于(yu)吉他手尋找便攜式的聲(sheng)(sheng)(sheng)音選項來練(lian)習。