Black Winter bridge resistance a bit off

[McBrain]

I just installed a new set of Black Winters in my Schecter C1+. My initial thoughts are that they sound kinda bass heavy and a bit mushy. Before ordering them, I read a lot of reviews and didn't expect them to have such a booming low end. I probably just need to get used to the flat eq and spend some more time adjusting them.

But before installing them I measured the DCR with my digital multimeter and got these readings:

Neck: 12.7 (specified: 13K)
Bridge: 15.7 (specified: 16.6K)

The neck pickup is pretty close to the specs from the website, but the bridge is a bit too low.

Is it normal for SD pickups to be this far from specs? These are my first Duncans in a while, but I have measured several of my pickups from Bare Knuckle, Dimarzio and Gibson over the years, and they all measure very close to the specified resistance. Hell, even the Duncan Designed that I pulled from the Schecter measured very close to the JB/Jazz set they are based on.

 

[Artie]

Re: Black Winter bridge resistance a bit off

Those numbers are insignificant. Normal tolerance is around 10%. Add in temperature variation and meter accuracy, and you're dead on.

 

[Masta' C]

Re: Black Winter bridge resistance a bit off

Play with the height adjustment a bit, as well (lower the bass side slightly)

 

[Mincer]

Re: Black Winter bridge resistance a bit off

Yes, this is normal...DCR isn't an absolute number. It will vary with temperature and other factors.

 

[cjenrick]

Re: Black Winter bridge resistance a bit off

I do not believe it is a temp issue and 10% is a pretty loose figure for wire variations.

Yes, a spool of #42 will change a bit as it is being de-spooled, but there is so much wire length in a pickup that these differences tend to average out.

I am doing some experiments right now to try and get a handle on why DCR measurements seem to get weird with pickups.

I am finding out that different meters will have more error than others when measuring a pickup.
I believe it has something to due with the inductance of the pickup. Why do i believe this? Because when winding pickups, the DCR of the loose coils does not match the DCR of the coils when assembled onto the magnet plate. In one case, the error was 1 K ohm on a 10 K pickup!
It will vary on which type of meter you use, therefore, the "core" of the inductor, that is, the slugs and screws and the magnet, will be biased by the DC to different levels depending on what type of batteries the meter uses etc. I just ordered an analog ohm meter to compare it with the digital meters. This will tell if it is the chips in the DMM's that do not like inductance.

A pickup with more turns will probably show more error due to increased inductance than a pickup with less turns.

From> http://schuetzmesstechnik.de/index.php/portfolio/mr-270-c-a/

"For the measurement of winding Features resistances of motors and transformers it is important to use as high a measuring current as possible, so that the magnetic circuit, the iron, comes close to saturation, which is necessary to obtain stable results, in particular in the case of power transformers. At the same time the measuring instrument must “wait” until the measuring current flows uniformly and stable measuring results are obtained. The measuring time is therefore extended automatically until a stable measuring situation is obtained. "

There might be other things going on also, like small AC signals being induced into the coil from lighting or other stray sources. But that is just a theory at this point. It could be easily checked by holding a pickup under test up to a light fixture of some sort and seeing if the ohms change.

Temperature is not the reason for this weirdness as I have measure coils on a table and retook measurements a few minutes later after installing pole pieces and the meter changes.

Some people have experienced meter drift while checking DCR and I feel that this has been erroneously been written off as temp coef. thing, but copper does not change DCR that radically. I believe it might be due to the fact that the coil is slowly being energized as you leave your meter hooked up with that DC flowing thru the coil.

To see this effect, simple take a pickup DCR reading, remove the pole piece screws, and re-measure.

I have tried to measure audio transformers with nickel cores with a DMM and in some cases, (Peerless mic input xfmr) the display started freaking out and flashing back and forth between crazy numbers, this is when I first suspected that DMM's do not like inductors.