Custom Ampex 350 mic pre. Take a look at the detailed pictures as we chronicle Obeid’s mods to the unit. First the unit was fully re-capped as well as the power supply. The Ampex 350 has over 90 db of gain in stock form! It was designed for low output ribbon mics and distant miking techniques. Obeid reduced the gain so that the pre could be used with high level microphones on a close miked loud source without input stage clipping. The input transfer switch has been modified to provide MIC/ 20 dB PAD and Instrument input functions. A ¼” jack is used for the high impedance instrument input. Phantom power is added on a front panel switch. Some tweaks to the output amplifier negative feedback loop round out the package and yield a maximum gain of 69 dB. Frequency response 1 dB points are 15 Hz – 35Khz and the original Ampex/GTC transformers are re-used. This modification turns the Ampex 350 into a useable device in any modern studio with the reliability of a brand new unit. Obeid has been doing this mod since 1993 for many studio’s and producers. Price for the complete mod is $500, contact Obeid for details.