2. analog
  3. 1330879257

Can magnet placed beside cartridge damage a coil?

I received a 20 year old NOS cart from a dealer which I resold as new but ended up having to refund the payment back to the buyer after he found it to have a channel imbalance issue.

I sent it back to the dealer to check out and he says there is a large difference in coil readings of 1.3 (normal) vs. .8. He says he tested his entire stash of these old carts prior to selling them and says the only explanation is that somehow a magnet was placed close to the cart either during transport or by the person I sold it to and thereby damaging the one coil. He therefore assumes no responsibility to replace it.

Would this be possible?
frankk

Showing 2 responses by almarg

almarg's avatar
almarg
9,670 posts
 
He tried to re-energize it by running current through it with a small 9vdc battery but it did not work.
I sure hope that he had a suitably chosen resistor in series with the battery. Otherwise I would expect doing that to result in the 0.8 mv becoming 0.0, permanently!

Regards,
-- Al
almarg's avatar
almarg
9,670 posts
 
Correction from above where I mentioned the reading was output volts. It was micro-ohms.
If that is what the person told you, he absolutely does not know what he is talking about. 0.8 micro-ohms is for all practical purposes an unmeasurably small amount of resistance, and is more than a million times smaller than the resistance of any cartridge coil that I am familiar with. It is also something that would be unaffected by a magnet, as Rodman indicated earlier.

The only sensible interpretation of the 1.3 and 0.8 figures seems to me to be the output of the cartridge as measured in millivolts (mv), for the two channels respectively, when playing a standardized test track.

Regards,
-- Al
More to discover