Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now


MRL, Supplier of Calibration Tapes, Will Close

“Time has finally caught up with our personnel and equipment”

Magnetic Reference Laboratory will close its doors at the end of the year.

The company, founded 51 years ago, makes calibration tapes for analog open-reel recorders. Its co-founder Jay McKnight died late last year.

Calibration tapes contain test signals used to measure and adjust a tape reproducer to conform to accepted standards. McKnight had worked at Ampex for three decades and also served in the U.S. Army with the Armed Forces Radio Service. He was a prominent member of the pro audio community. Among his many career highlights, he was a member of an advisory group to Judge John Sirica on the White House tapes during the Watergate investigations.

[Read about the impressive audio career of Jay McKnight at]

“Over the past decade, we have done our best to continue supplying a quality product, but time has finally caught up with our personnel and equipment,” the company states on its website.

The firm, which is based in San Jose, Calif., will accept orders until Dec. 29.

“We would like to thank all of our loyal customers and dealers who have stuck with us through all these years. You have been an integral part of our longevity and success.”

The company’s website contains a number of technical papers on the use and calibration of analog tape recorders. At one time MRL also made calibration tapes for cart machines.

[Read a 2006 profile and interview.]