Recommended Tape Head Demagnetizer?

[Ron Resnick]

I have been playing tapes a lot but I have not demagnetized my tape hea

What tape head demagnetizer do you recommend?

I see the Annis Han-D-Mag? Is this a good one people standardly use?

I see there are different versions of this device:

Annis Han-D-Mags are available in 8 different models. The more usual, standard Model 115-S, short probe model has a 2 1/4" long probe that is .415" thick. Long probe models have a 4 1/4" long probe. Thin probe models are only .315" thick

Which is the easiest model to use on a Studer head-block?

Thank you!

 

[Foxbat]

I have never had any problems with the standard tip.

 

[Ron Resnick]

What is your exact procedure, step-by-step, for demagnetizing?

 

[Foxbat]

Standard procedure, nothing fancy.

Get a long extension cord and take off your watch. Turn the machine OFF and remove the tape.

Turn the tool ON at least 1 meter away, approach the machine and go point by point, sliding the tip up and down and sideways on every part that tape touches, gently touching them.

When done, move the tool back 1 meter and turn it OFF.

 

[Ron Resnick]

So the de-mag probe should physically touch the tape heads? I did not realize that.

 

[Foxbat]

Yes, it has plastic cover over its tip for that.

 

[astrotoy]

Don't move the D-Mag toward or back too fast - maybe 20 seconds each way. Larry

 

[Ron Resnick]

I ordered the Han-D-Mag, regular tip. Thank you!

 

[Ron Resnick]

The Han-D-Mag instructions say "waive the probe slightly."

Is your technique to bring the probe towards the tape head slowly and then remove the probe slowly, without moving the probe left and right or up and down? Or do you move the probe left and right in front of the tape head?

 

[astrotoy]

The Han-D-Mag instructions say "waive the probe slightly."

Is your technique to bring the probe towards the tape head slowly and then remove the probe slowly, without moving the probe left and right or up and down? Or do you move the probe left and right in front of the tape head?

I normally move the Han-D-Mag slowly across the three heads of my headblocks (both Ampex and Otari) after bring the probe slowly toward the heads and then slowly withdrawing the Han-D-Mag until it is about 20 feet away before unplugging the Han-D-Mag. Larry

 

[Ron Resnick]

I normally move the Han-D-Mag slowly across the three heads of my headblocks (both Ampex and Otari) after bring the probe slowly toward the heads and then slowly withdrawing the Han-D-Mag until it is about 20 feet away before unplugging the Han-D-Mag. Larry

Do you slowly wave it back-and-forth in front of the heads, or one continuous motion left to right or right to left?

You put an extension cord on the device to have a length of 20 feet?

 

[astrotoy]

Do you slowly wave it back-and-forth in front of the heads, or one continuous motion left to right or right to left?

You put an extension cord on the device to have a length of 20 feet?

Usually a continuous move. Not sure if it matters much. I do use an extension cord.

 

[Ron Resnick]

Thank you!

 

[microstrip]

Do you slowly wave it back-and-forth in front of the heads, or one continuous motion left to right or right to left?

You put an extension cord on the device to have a length of 20 feet?

A slow, smooth movement is mandatory. The main idea of demagnetization is that the sinusoidally symmetrical magnetic field decreases slowly, without discontinuities, until the peak field amplitude decreases to a very small residual value. Any abrupt change of field magnitude can magnetize the heads or surroundings, due to hysteresis. So the main idea is having a smooth continuous movement.

Magnetic field of a dipole scales with the inverse of the third power of distance. I consider five feet - my typical movement - a vey safe distance based on my measurements with my Akai demagnetizer.

 

[Ron Resnick]

A slow, smooth movement is mandatory. The main idea of demagnetization is that the sinusoidally symmetrical magnetic field decreases slowly, without discontinuities, until the peak field amplitude decreases to a very small residual value. Any abrupt change of field magnitude can magnetize the heads or surroundings, due to hysteresis. So the main idea is having a smooth continuous movement.

Magnetic field of a dipole scales with the inverse of the third power of distance. I consider five feet - my typical movement - a vey safe distance based on my measurements with my Akai demagnetizer.

Thank you!

 

[Ron Resnick]

The de-mag probe jumped to attach itself to the hinged Mu cover in front of the head block!

I am afraid I magnetized the whole works!

 

[Zeotrope]

The de-mag probe jumped to attach itself to the hinged Mu cover in front of the head block!

I am afraid I magnetized the whole works!

So what happened, Ron?

 

[Ron Resnick]

So what happened, Ron?

I performed the demagnetizing protocol, hopefully properly this time.

 

[Zeotrope]

I performed the demagnetizing protocol, hopefully properly this time.

Was there a difference in sound before and after?
Seems to be a lot of divergent opinions on whether to DeMag at all, and if so, how!

 

[Ron Resnick]

Was there a difference in sound before and after?

No, but I would not expect there to be a sonic difference. It is not like I have been using the machine for years and never demagnetized it along the way.