I have read that the two preamp tubes in the JMP-1 work one each for clean and the OD channels. I am swapping tubes arond and would like to minimize the swapping as they are mountes direct to the flimsy board, so I would like to know which tube corresponds with clean and which one is the OD? I am thinnking Tungsram ecc83; JJ ECC 803 or Mullard 12at7 for the clean and JJ ecc83; Mullard ECC3 or early 80's chinese for the OD. Thanks for the help. Happy New Year!