165 Wyandotte Dr, San Jose, CA  95123  USA
Phone and FAX +1.408.227.8631

Send orders, comments, and questions to us at MRL ().

Welcome to the
Magnetic Reference Laboratory
Home Page

[Last updated 2014-09-17]

Blank tape prices went up again in 2008, so
all MRL prices were increased after 2008-Apr-01.

The new price list is posted here
We can now make our Calibration Tapes on "ATR Magnetics" tape (announcement) -- MRL prices here.

Go to:
Catalog Pages (Part Numbers and Prices)
To Place an Order
MRL Technical Papers Available
More Information on Analog Magnetic Tape Recording
About MRL

Magnetic Reference Laboratory (MRL) makes and sells Calibration Tapes (what is a "Calibration Tape"?) for analog audio magnetic tape reproducers in the Open Reel format. We no longer make Calibration Tapes in the Broadcast Cartridge format. Other people do cassettes (we don't).

This page will lead you to all of our literature, which we have put into the Adobe Acrobat (PDF) format. You can download the free Acrobat reader from Adobe's website. If you are not able to download these publications, please email, call, or fax us, and we will mail or fax them to you.

Catalog Pages (Part Numbers and Prices):

To place an order:

Please contact us if you need further information, or have questions that were not answered in this literature.

MRL has been a Sustaining Member of the Audio Engineering Society since 1976

MRL Technical Papers Available

These papers answer many "frequently asked questions" on using analog tape recorders. They discuss both theoretical and practical matters, and supplement the information given in the manuals for tape recorders. They are available for downloading from this website. The Standards (for instance IEC Standard 60 094, Part 1), and the tape recorder manuals, both say to set up your tape reproducer gain and equalization from a "Calibration Tape" such as MRL makes. But you may have wondered how MRL measures the response and fluxivity in the first place.   Well, we do it from first principles that are explained in the technical paper "Flux and Flux-Frequency Measurements and Standardization in Magnetic Recording". Another paper, "Tape Flux Measurement Revisited , explains both an ac and a dc flux measurement in detail, with examples.

MRL President Jay McKnight has published over 70 papers on analog magnetic recording and audio engineering. Topics include the design of magnetic recording heads; the magnetic erasing, recording, and reproducing processes; signal and noise considerations; frequency and wavelength response, measurements, standardization, etc; audio systems and practices; program level indicators; tape transport design, flutter measurement, etc; and miscellany. Many of these were published in the Journal of the Audio Engineering Society. They are listed in the Bibliography of papers by J. McKnight, and many of the PDF files of the papers are linked there.

More Information on Analog Magnetic Tape Recording

About MRL

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Updates for this home page

Added links for motion-picture calibration films from Sondor.
Deleted links to Pub644 and Pub673; added links to Pub070+LF and Pub 043+LF
Link to Studer List restored -- still operating;  CA state tax rates updated
International Monetary Transfer information updated.
Older updates moved to here
The update of the home page from 2008-03-17 somehow got lost; reinstated here. Link to "Studer List" removed -- defunct.
Major update of pubshed
Updated "Azimuth in a Magnetic Tape Recorder"
Added alternate email address for anyone having difficulty contacting us at the address.
Price increase from 2008-04-01, PubPL2008 ; available on ATR Magnetics Tape; international dealers updated; prepay removed -- nobody does it
Minor cleanup; added jm biography link.
2007-12-26 Added explanation of MRL Catalog Numbers to the "List of Publications"
Bibliography of papers by J. McKnight now includes links to PDF files of many of the papers.
Ref to prices changed to "pubpl2006.pdf"
Price increase, 10 $ per item from 2006-11-03; new address & fone/fax.
Added link to Jack Endino's measurements of "head bumps"
Added para "Delivery"; update "More Information..."