Ampex 601 dual preamp unit built by tech Jim Miller.  This is a complete re-build / modification of the unit.   This is Jim's favorite Ampex tube electronics to mod as preamp due to perfect balance between low noise (more modern tubes)  and classic transformers and circuit design. Each channel can be switched to use Peerless 15095 or original Ampex transformers. All tubes ( EF806, 12AU7, 12AY7, 5Y3) are NOS handpicked and tested or brand new JJ equivalents.What Mr. Miller has built here is a completely different beast from the original tape electronics unit.  This is an incredible sounding tube preamp unit w/ all options for modern integration.  Even termination is included.  Wait time for one of these units is incredibly long, if you can get on the waiting list.   This is your chance to acquire one of these one of a kind units asap.For more details/manual on these units google "fixthatmix"Good luck !