MRL LIVES! (CALIBRATION TAPES STILL ROLLING)
Tom Fine
Magnetic Reference Laboratory, the last US-based maker of industry-standard analog calibration tapes, is rising after a near-death experience and, if all goes well, is expected to have resumed regular production by the time you read this.
As reported in January’s Industry Update, MRL, the last American manufacturer of alignment tapes, was in the process of closing up shop due to the deteriorated condition of its antique equipment. Alignment tapes are essential for recording, playback, and digital conversion of analog; they’re the only way to ensure that a tape machine’s playback equalization and the azimuth of its magnetic heads are set to a standard.1 Company owner Jay McKnight died in 2022, leaving the company to his heirs. Former operator Chuck Booye, who ran MRL out of his garage, stopped accepting new orders in mid-December of 2023—and had been feeling hard-pressed to complete the orders he had in hand due to the aged condition of the equipment. Moreover, he’d been operating it as a one-man show for the last 15 years.
In the time since Stereophile reported that story, McKnight’s four sons have reconstituted the company. Jeff, the second son, is running it as interim CEO. The production equipment is in a commercial building in Half Moon Bay, California, operated by Ben Cortez, a long-time MRL engineer who designed and built much of the proprietary electronics. Efforts are underway to modernize the plant, especially its ancient computer system.
The first new-production tapes were shipped in late February. In a phone interview on February 27, Jeff McKnight told me he had just made a breakthrough in modernizing and somewhat automating the ordering system and was prioritizing back orders so those who needed a calibration tape yesterday will get one soon. He hopes to work through the order backlog by midyear, but it may take longer. “That’s assuming the computer and the equipment continue to function,” he said.
Jeff told Stereophile that MRL is receiving helpful advice and other assistance from a brain trust of magnetic recording: tape machine expert John French of JRF Magnetic Sciences; magnetic head maker Greg Orton
1 There are several playback-EQ standards, the most common being IEC (formerly CCIR) and IEC2 (formerly NAB). Playback EQ alignment is different for each tape speed; common pro-audio speeds are 7.5, 15, and 30 inches per second, and common consumer speeds are 3.75 and 7.5ips. Azimuth is ultimately adjusted to the tape being played, but alignment tapes offer a “studio standard” alignment to which an individual machine’s play, record, and erase heads can be set so that they operate correctly together.
of Flux Magnetics; and design engineer John Chester, who built the original sound system at the legendary Fillmore East and helped construct and run the sound and light system at Woodstock. Chester, who is now the tape-transfer expert at Plangent Processes, is currently at work updating MRL’s control system, moving from a 1990s computer made before PCI cards or IDE hard drives to a modern automation system, likely on the Raspberry Pi platform.
According to Jeff, MRL’s two customized Studer A80 tape machines (one for 1/4" and 1/2" and one for 1" and 2" tape widths) “seem to be in mechanically good shape,” though he acknowledged that they are 40 years old and will need some refurb work. Orton is fabricating new, custom ceramic recording heads; all MRL tapes are recorded full track with magnetic flux out to the edges of the tape, which requires purpose-built heads. Playback heads are a simpler proposition: The system uses stock Studer playback heads, used to perform QC checks, akin to how the calibration tapes are used in the real world. When he does need replacements, which Jeff McKnight said will be soon, he’ll be able to source them through French.
These developments should come as good news—even a relief—for any analog fan. It bears repeating from our prior report that everyone who buys anything made from tapes—be it AAA LPs, reissues of recordings made prior to relatively recent history, etc.—should be concerned if the main playback calibration standard for all tape machines is at risk for extinction. It sounds like this disaster has been averted.