Studer and others Head shield

[panreels]

I have notice on some Studers, Revox and my Tascam 42B there is a square flip up head shield on the head stock, dose anyone know what this is used for? The owners manual calls it head shield assembly and nothing more also I can’t find anything on the internet.

 

[dcc]

These are hum shields actually.

 

[Tapetech]

A power transformer in a power amp will emit a rather strong electromagnetic field (EMF) that can travel several feet. If your tape deck is near that amp, the play head in a tape deck can pick up/detect that field which gets amplified by the play amplifiers, producing 60Hz tones (and harmonics of those tones) at the output of your tape deck. Commonly referred to as hum and/or buzz. The head shield blocks most of those electromagnetic fields from getting into the play head.

 

[Coteluc]

Even with the head shield I had to apply MuMetal sheets under the top shelf to eliminate the last of bit of Hum coming thru. I have 2 Audio Research REF 250 that were just too much EMF for the decks.

After experimentation I applied 4 stacked sheets right under the head position then covered them a with matrix of 4 sheets in a single layer over a larger area. Worked out to 5 layers 8X10.5" directly under the heads and 1 layer 21" x 16" covering the whole area above the Amps.

Products:
https://www.partsconnexion.com/CONNEX-76151.html
https://www.nooelec.com/store/mumetal.html
Duct Tape all around!

 

[Tapetech]

Even with the head shield I had to apply MuMetal sheets under the top shelf to eliminate the last of bit of Hum coming thru. I have 2 Audio Research REF 250 that were just too much EMF for the decks.

After experimentation I applied 4 stacked sheet right under the head position then covered them a with matrix of 4 sheets in a single layer over a larger area. Worked out to 5 layers 8X10.5" directly under the heads and 1 layer 21" x 16" covering the whole area above the Amps.

Products:
https://www.partsconnexion.com/CONNEX-76151.html
https://www.nooelec.com/store/mumetal.html
Duct Tape all around!


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Yikes! You were asking for trouble by putting that power amp so close to the tape deck to begin with. I would have moved the power amps, but if your solution works, then good for you. Does your Studer have a front head shield? (a flap that covers the face of the head)

 

[Coteluc]

Yikes! You were asking for trouble by putting that power amp so close to the tape deck to begin with. I would have moved the power amps, but if your solution works, then good for you. Does your Studer have a front head shield? (a flap that covers the face of the head)

The Studer have a flip cover, the Lyrec also have some shielding on the top cover but not on the head face itself.
I had more hum from the Studer before shielding the shelf. I also have a Nagra IV/S that I rotate on the same spot and the shielding fix that one also.

The Amps are located in the only spot that I had for them, not optimal but It works with the shielding.
Spending $200 on shielding was cheaper that a larger loft!