Ive just received some more Iranian test enths, off my old source, who I trust 100%, and the batch number is 5012, MFG:2. 2007, EXP: 2.2012...
They look almost identical to the 6020's I had, except for a few minor differences, which is making me think the 6020s are counterfeit, just small things like the quality of the print on the amp and the expiry date does not rub off on the 5012's... also the batch number on the box of the 6020's don't match up to the batch no. on the amps, and ive seen someone elses on a forum (may be this one), that had the same....
However, after seeing emails saying 6020's were made by them, and having not seen any 6020's that look different, maybe they did change the design again in 2007...
I still think is definatley testestorone in the 6020's and 6021's as Ive made some good gains, but I question theyre authenticity to be what they say they are....