http://www.eurotubes.com/euro-Marshall-DSLTSLV.htm http://www.youtube.com/watch?v=LzFuUBERc_4&feature=PlayList&p=E6293B4427D68537&playnext=1&index=31 http://www.marshallforum.com/workbench/3185-replacing-dsl-100-tubes.html http://www.modernmusician.com/forum/showthread.php?t=135574&highlight=jcm2000 pictures from Marshall forum DSL 401 可以調偏壓, 只是不是 external 的而已 (危險性提高) pictures from EuroTubes