1950s Collins 356B high gain tube preamp or program / monitor amplifier. Same circuit as the Langevin 117a. The original, excellent, ADC transformers are guaranteed but this unit has been untested and the original capacitors must be replaced before applying power. Fantastic preamp for high gain use (ribbon mics, etc) once restored. Datasheet, schematics and test harness included. Tubes included but untested.