Hello,
I have an Ampex 351-2 deck that has been modified to provide both NAB and IEC equalization. Ironbut suggested that the details of that modification might be interesting to other forum members. An Ampex document that details the required modification is available at the following link:
http://www.moshier.net/catalogues/Ampex_CCIR.pdfI originally got the document from Dave Dintenfass of Full Track Productions in Seattle. Dave is active on the Ampex mailing list, an all-around nice guy, and a good source for info about (and some parts for) Ampex machines. He was also able to recommend a local tech in Chicago who did the work. On my deck, equalization is switchable via the Tape Speed/Equalization switches on the front panels.
I hope this info helps anyone who wants to use an Ampex 351 to play Tape Project tapes. I've had great results with mine!
Regards,
John Stover