今天把KnuckleheadReverb 5根12A×7換掉 不知道為心血來朝想查一下後及的偏壓.... 還好手冊有教!!! 就把電表的那兩個探頭按在手冊上說的兩個Test Points!!!! 哈哈感覺滿安全的啦!!! 但....為什座表上沒什麼數值跑出來呢?? 好!!換檔!!!扭了個360°.... 只[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]有dcv[/FONT] 200m [FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]那[/FONT]檔出現3.2v 是我有什麼地方出錯了嗎?? 手冊上也有偏壓的提意!! 其實我是想參考本來的偏壓和方法 為下一次要換power tube時先了解一下!! After the tubes warm up, observe the idle current. For 55 Versions (2 output tubes),adjust for 80-90 MaDC. For 100 Versions (4 output tubes), adjust for 160-180 MaDC. The actual setting you choose will depend on the particular tubes used and their DC Current gain. For example, a really high gain EL-34 should be biased colder (40 MaDCper tube) then a low gain tube which may sound best run hotter (45 MaDC per tube).
對~ 原理是相同的~ 找 amp tech 或是自己 DIY 在 pin1,pin8 和接地之間接 1ohm resistor 加上幾個零件在機殼上就可以當 bias test points 了 http://deluxereverb.waynereno.com/Bias_Test_Points.html