You have come upon a. It was completely overhauled, the electronics, tube stages, etc... The original unit came with a reel to reel (which I still have) and in order to use it with modern mics you would have needed to do quite a few things. You really couldn't just plug in a mic and be off and running, especially the 600.
A lot of others you see online are not modded and you really can't get a lot of use out of. They do not work'out of the box' like you are hoping they will. This unit was modded at Glorytron in Austin, TX. Morris did a killer job! Please go to my youtube video at the link listed and have a listen.
I also explain a lot about how to get the most out of this. It's a vintage piece of equipment, not a digital plugin with a preset.
You really need to know what you are doing. The unit is in excellent working order, the VU meter tends to'stick' at times but is functional and gives you accurate readings. I'm sure its easy to fix, I'm just not that guy. Controls are as follows from the left of the unit to the right. Mic Input Gain ------ Mic Pad -20 Db off/on ------ Phase Polarity off/on ----- DI input 1/4 inch cable. I want it to arrive safely, I'm sure you understand. Feel free to ask questions, watch the video you youtube. The item "Ampex 600 Modded Tube Mic Pre" is in sale since Tuesday, December 12, 2017. This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Preamps & Channel Strips". The seller is "innovativewrshp" and is located in Cumming, Georgia.This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Israel, Mexico, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia.