reel to reel calibration/ fostex r-8 help

[arkestra]

Hi all Im new to analog recording and recently got a fostex r8 to make wierd music with. I was wondering what the proceedure for matching the record levels on this deck is. I did a not very scientific test by recording a tone at the same level (according to the built in db meter) on all 8 channels. On playback channels 6 and 8 were quieter than all the rest. I cleaned the head so dont think it is that. Any help would be appreciated. Also im on an "ultra budget" and looking at large diaphragm condensers. Anyone heard of or tried Apex mics? do they sound as cheap as thier price? thanks