Hi, this is my first post. I've been lurking on here for years and soaking up a ton of great info, so a big thanks to all the contributors! Now to my question... I've been sourcing out components to put together an Ampex 351 recorder. So far I've got a line on a 351 transport with ag440 electronics which I'll probably use in the meantime until piece together the 351 electronics. The transport can be used as a 4 track or a 2 track because it has switchable guide posts. If anyone has any info on this configuration please let me know. Was it a reliable setup? I like the idea of having the option using either 1/4" or 1/2" tape depending on the project. As for the electronics, I've sourced some 351 slave units. The catalog number is 30750-9 which I can't find any info on. I know that certain numbers correspond to being used with either 7.5ips/15ips transports or 15ips/30ips transports. Or does it really matter? Will any 351 work with any transport? Any info on these particular model numbers would be appreciated. And final question... If I wanted to put together a four track, how many master and slave units would I require? Would just one master work with 3 slave units? Thanks in advance for any and all replies! Cheers!