If listings do not mention which version of the AD-900 is for sale (the two chip or four chip version) then all final sale prices get entered here. The four chip version of the AD-900 contains MN3008 transistors. The earlier two chip versions are listed as having the MN3005 which apparently is no longer in production. The MN3005 version may be rare and was perhaps intended for the Japanese market only. The production run on the AD-900 may have ended in 2003.