demagnatizing question

  • Thread starter Thread starter famous beagle
  • Start date Start date
famous beagle

famous beagle

Well-known member
or ... demagnetizing rather.

I've read several places on here that the cheaper $30 demags will work fine for cassette 4-tracks, but for R2R machines, you need the Han-D-Mag.

I'm not saying that I don't believe this, but I'm just wondering how this is confirmed. Is there a way to measure the effects of a demag?

Thanks!
 
Han D Mags are stronger. You can even feel it when you use them.


I bought mine last year from Markertek for $49.95, it was a no-brainer.
 
You could measure the relative strength of the magnetic field using a tape head or a guitar pickup. I guess the hum output would indicate the strength, using a given distance from the demag tool.

Bottom line is good ones are not expensive as briank said.
 
There is a device to measure gauss but they are spend and rare. There really isn't a practical need for one in the studio afaic.

So I can't give you quantitative data but how about a case study?

I had an aggravating problem with the Tascam 58 I used to have. I had degaussed the tape path using the lame-o demag wand. I thought all was good. I'd never used a "real" demag unit like the Han-D-Mag and I just assumed all was good. I was getting clicks and pops printed to tape even when I wasn't recording...just having tape pass over the heads was printing the pops and clicks to tape. I assumed it was a problem with my electronics. As I recall Beck and some others helped me figure it out and in the end the heads had not been properly degassed even though I executed the procedure correctly. The tool was the problem. I put that thing back in the box, bought a used new-condition Han-D-Mag for $50 and have never looked back. First time I used the Han-D-Mag it was like "oh wow". It took care of the problem. To be honest I won't even trust the lame-o unit on my cassette decks, and if it won't work on a 1/2" 8-track head then sure as shootin' its not gonna work on a 1" or 2" stack.

I'm all for creative and frugal solutions but as time has passed I've resorted to buying proper tools for the job:

Han-D-Mag
Tentelometer
Spring guages (stopped using my home-brew versions)
Analog oscilloscope (vs. soft-scope)
DMM with audio-band spec

These are all things I tried to work around by using home-brew or cheap solutions and in the end it just caused me more headaches. It all depends somewhat on how deep you are going with the maintenance aspect and what your standards are, but I'd say the demag unit is the most no-brainerish on the sample list above.
 
sweetbeats said:
There is a device to measure gauss but they are spend and rare. There really isn't a practical need for one in the studio afaic.

So I can't give you quantitative data but how about a case study?

I had an aggravating problem with the Tascam 58 I used to have. I had degaussed the tape path using the lame-o demag wand. I thought all was good. I'd never used a "real" demag unit like the Han-D-Mag and I just assumed all was good. I was getting clicks and pops printed to tape even when I wasn't recording...just having tape pass over the heads was printing the pops and clicks to tape. I assumed it was a problem with my electronics. As I recall Beck and some others helped me figure it out and in the end the heads had not been properly degassed even though I executed the procedure correctly. The tool was the problem. I put that thing back in the box, bought a used new-condition Han-D-Mag for $50 and have never looked back. First time I used the Han-D-Mag it was like "oh wow". It took care of the problem. To be honest I won't even trust the lame-o unit on my cassette decks, and if it won't work on a 1/2" 8-track head then sure as shootin' its not gonna work on a 1" or 2" stack.

I'm all for creative and frugal solutions but as time has passed I've resorted to buying proper tools for the job:

Han-D-Mag
Tentelometer
Spring guages (stopped using my home-brew versions)
Analog oscilloscope (vs. soft-scope)
DMM with audio-band spec

These are all things I tried to work around by using home-brew or cheap solutions and in the end it just caused me more headaches. It all depends somewhat on how deep you are going with the maintenance aspect and what your standards are, but I'd say the demag unit is the most no-brainerish on the sample list above.
Click to expand...

Thanks for the info. I imagine I'll just bear down and shell out the scratch when I have it available.

One more question: How often do you demagnetize? I've heard a wide range of answers on this: from "every time I clean the heads" to "every 250 to 300 hours."

A tentelometer? Where did you even get one? The only place I could find them online, they were like $650 or something!
 
I got my Tentelometer used for $200 a couple years ago.

I don't know if this right/good or whatever, but I demag before I put a cal tape on a machine. So not very often. But I want to make sure if there is any gauss on the heads that that isn't doing any HF partial erasure on my cal tape.
 
R.B. Annis made a magnatometer. Used to check residual magnetism in the heads. Not very expensive if I remember correctly. I still have one, but I don't know if they make them any more.
 
As precautionary, and in following the most common regimen suggested to me by my peers, I demag always before spooling the MRL, and generally every 10 hours or so, which equates to every day-long session or every other half day session. Personally I prefer to err on the side of caution, especially since they're pro sessions.

As for the Tentelometers, we do have one (not sure where it came from) and I used it a fair amount when first aligning and getting to know the machine. It helped me get our MCI machine in the ballpark but from there I learned the nuances of keeping this machine's tensions happy by hand/ear. I'm not sure how different such procedures are with prosumer decks but it's pretty straightforward on the MCI machines once you get the hang of it. The Tentelometer is not something I use all the time, but nice to have if things get too far out of whack for some reason.
 
Thanks for the input everyone! I have a Fostex R8 that I'm finally getting ready to track to in a month or so after I finish remodeling my studio (installing wood floors right now). It looks basically brand new, as do the heads.
 
You must log in or register to reply here.
Back
Top