It was factory serviced and calibrated last year. In March of 2016 I sent the unit to the factory to add 2 more channels. At that time all channels were checked and calibrated. It's had only light use sine it was serviced.
This M1 works perfectly and looks great too. If you're viewing this listing you probably already know about the John Hardy M1 preamps. The M1 is a recording industry standard.Plenty more info available on the web so I'll say no more here. The item "John Hardy M1 mic preamp-4 channels with VU-1 meter and JT-11-BMQ transformers" is in sale since Sunday, August 13, 2017. This item is in the category "Musical Instruments & Gear\Pro Audio Equipment\Preamps & Channel Strips". The seller is "alanackoff" and is located in Santa Fe, New Mexico.
This item can be shipped to United States.