Moving Coil Cartridge Question
 

I've been fighting what I thought was a turntable grounding problem while using a moving coil cartridge, Denon dl-103r. After a lot of frustration, I think the problem might be with the cartridge itself. Using a digital multi-meter, I found that the Denon has electrical continuity between the signal and ground post in each channel. Checking a moving magnet cart (A/T 12), there is not similar continuity.

Is this behavoir to be expected in the moving coil Denon?

Thanks

An MC has far lower resistance in its coils than an MM. That would explain your readings. There are lots of ways to get a hummy setup and very few ways to have a hum free setup, so keep plugging at all the other possibilities.

Boy, that's the truth.

Thanks, Sy.

Usually, the grounding problem can be located through simple continuity checks. Perhaps a broken solder joint at an RCA plug. Or a break within the tonearm wires.

Getting just the right fit between cartridge clips and posts seems to be an art arrived at through practice. Needs to be a snug fit.

Oxidization of the metal at all the connection joints is something to be chased away.

stuff like that.

-Steve

The Denon DL103R is specified with a coil resistance of 14 Ohms. This can easily be mistaken for a short.

Good input, thanks.

I've been doing continuity checks for a while and re-soldered several suspect connections. I usually, work on it when I've got an hour or two over the weekend. It's a mechanically complicated Pioneer PL-570, a bother to disconnect, and a risk that I might screw up something when poking around. As noted, in a perverse way, it would have been a relief to blame the whole thing on the cart (an expensive relief, however). I'll keep looking.

Thanks.

I wonder how did the coils in the cartridges survived the continuity test!

Maybe they didn't.:eek:

jeff

In fact putting an Ohmmeter on the coils of an MC pickup isn't the best idea at all. Just adding a few Kiloohms in series eliminates the danger, and basically offers the same results (a few kiloohms - coils are fine; open circuit - coils are gone).

I'd guess no problem- the current through those testers is usually relatively low, and the low coil resistance means that any power dissipated is minuscule.