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ABOUT OUR CALIBRATION TAPE

 

 

 

Introducing our groundbreaking product, where the most challenging aspect lies in measuring the variables of magnetic fields.

We have developed an original methodology based on theories of measuring variable magnetic flux on carriers. Our approach is grounded in fundamental principles of theoretical data and analyses presented in articles, including contributions from Jay McKnight, who has significantly advanced the application of this methodology.

Utilizing our proprietary measuring instruments, developed based on the methodology at AMPEX, alongside cutting-edge measurement devices such as those from Audio Precision—devices that were merely dreams for AMPEX back in the 1960s—we ensure the utmost precision.

The control of theoretical calculations and practical measurements is facilitated by modern software that models processes within electronic circuits. To ensure recording and quality control, we employ specialized magnetic mono heads manufactured by FluxMagnetics.

All of these efforts culminate in achieving maximum accuracy of magnetic flux (including flux level, azimuth, and equalization) recorded onto magnetic tape, fully compliant with the requirements of the international standard IEC 94-2.

 

 

 

MSRP (1/4"):

7.5 ips - $150.00

15 ips - $150.00

30 ips - $160.00

Double Speed - $210.00

CCIR / NAB / AES

any flux level

*Shipping and Taxes Not Included

 

NOTE: We currently only offer 1/4" size tape. 1/2" size will be available soon.

Please fill out the form and we will get back to you ASAP with a quote.

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Q & A

What is the difference?

There are numerous sources of alignment tapes available on the market.

Based on our experience and feedback from customers/studios around the world, there are no trustworthy reliable source that can be used as a reference etalon.

We have tested over 30 pcs of alignment tapes - in past ten years of production we've seen every tape has an azimuth differ substantially (some even up to +/- 60 degrees!), the flux level dropped by 25%, tones level "dancing".

 

No wonder why some users complaining about a quality of recorded tapes, just because of a "tape producer" trust to whatever alignment tape and had no idea that levels are off, and some users never even bother to align their machines (but that's another subject).

 

There is the International Electrotechnical Commission (IEC) Standard 94, "Magnetic Tape Sound Recording and Reproducing Systems" with parts 2 "CALIBRATION TAPES":

 

- "Tape for making adjustment and comparative assessments of the reproducing performance of both professional and domestic magnetic tape recording/reproducing equipment."

 

- "Each standard calibration tape shall have at least the following sections:

1) reference [fluxivity], 2) azimuth, and 3) amplitude/frequency response."

 

For instance, for speed 15 ips, requirements for the alignment tape: 

 

- Reference flux level (nWb/m), tolerance +/-5%

 

- Signal at reference frequency (1kHz), distortion up to 1%

- Level fluctuation up to 10kHz - <0.5dB; over 10kHz < 1dB

- Recording angle of 90 deg +/-1` (Azimuth about 0 deg)

We have developed a process of measuring and recording to meet all required by standard (see above) conditions.

 

An original methodology based on theories of measuring variable magnetic flux level, tone signals level and azimuth.

 

Utilizing our proprietary measuring instruments, developed based on the methodology at AMPEX, alongside cutting-edge measurement devices (deviation = 0.01% of frequencies and magnetic flux level) we ensure the utmost precision.

 

To ensure recording and quality control, we employ special full-size heads developed by FluxMagnetics.

 

All these efforts culminate in achieving maximum accuracy of magnetic flux (including flux level, azimuth, and equalization) recorded onto magnetic tape, fully compliant with the requirements of the international standard IEC 94-2.

 

As an audiophile guy I can really hear a benefit of the correct azimuth alignment - precise calibration would give you a pleasure of better sound stage, details, space.

 

Next topic we can do about a fringing effect (low frequencies playback abnormal effect). That would be an interesting subject.

 

Please contact ATR Service anytime if questions.

What is the fringing effect?

  • Link to Journal of the Audio Engineering Society (Jay McKnight paper)

  • Pages from Ampex ATR manual

What is the equipment setup for recording magnetic flux on calibration tape?

An amplifier has been developed and manufactured to work with the magnetic flux loop. It is calibrated with an accuracy of 0.01dB to perform frequency correction at various tape playback speeds. The actual frequency response of the amplifier fully matches the calculated and simulated responses. The reference model for comparison of correction is an R+C circuit.

  1. By using the magnetic flux loop and amplifier, we have achieved the ability to adjust the playback amplifier circuit with an absolutely flat/linear frequency characteristic with constant times corresponding to selected speeds and standards.

  2. For measuring the level of magnetic flux, a special reference measuring head was manufactured (by FluxMagnetics) and a high precision integrating amplifier was used.

  3. Knowing the characteristics of the measuring head and the parameters of the integrating amplifier at a frequency of 1 kHz, the level of recorded magnetic flux is calculated with sufficient accuracy (measurement error does not exceed 1% or 0.1 dB).

  4. Based on the obtained values, signal recording level correction is performed.

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