Rickresource Rickenbacker Forum

My '74 Rick output is so low (all together now: "HOW LOW IS IT??") that I find I really have to crank my Ashdown head's gain, especially in comparison to my G&L L2000 in passive mode. I recently installed a push-pull vintage tone circuit, but the install didn't affect the output as far as my ears can tell so the condition was apparently pre-existing. Can anyone direct me to info about how to test pickup output? If it turns out my pups are tired, what are my options?

Thanks,

Tom

That's a good Carson line

Testing the actual output signal requires you to have some pretty sensitive test equipment. However, a rough idea of how "healthy" the windings are inside the pickups can be gained with a simple VOM (volt-ohm meter). With one of the pickup leads unsoldered, just bridge across that lead and the other lead of the same pickup, still soldered to the wiring harness, with the test probes of a VOM. Set the VOM to the 20k scale for measuring resistance. You should see, depending on the type of pickup, anywhere from 5 kilohms to 15 kilohms. If there are shorted windings in a pickup (which is the chief cause of unnaturally-low output in a pickup), then the resistance will read much lower. If the pickup was built with more windings to boost output, the resistance reading will be higher in rough proportion to the expected increased pickup output.

The other reason for low output is of course the position of the strings in relation to the pickup pole pieces. If the action is too high, then the output is lower. If the strings are offset from the sweet spot right over the pole piece, that output will be lower.

If you make sure each string is aligned exactly over each pole piece, and the spacing between the underside of the string and the top of the pole piece is as small as you can get without ever actually hitting the pole piece with a heavily-plucked string, then you have maximized output due to string positioning.

And if your pickup shows unusually-low resistance, replacing the pickup, or getting it rewound, will increase output.

And if the problems is equally-low output with both pickups, and the pickups themselves test with relatively-high resistance, then it is a problem in the wiring harness itself.

Hope this helps, Tom!

Both pickups or just one?

Unless you're looking for exact DC resistance readings from the coils of your pickups, it's not necessary to unsolder one of the leads. Just set the pickup selector switch to the pickup you wish to measure, make sure your volume controls are all the way up (tone controls won't make a difference), and measure across the pickup leads. I take it the bass in question is the '74 4001 listed in your profile. It will most likely have the 0.0047 microfarad cap in line with the treble pickup. Therefore, it would be best to measure the pickup leads themselves rather than at the jack, which would show an open reading for the treble pickup due to the cap.

Your bass probably has hi-gains in it, expect (good) readings to be between 10k-12k ohms.

Right, I forgot and Kris is correct - if you don't want exact readings, you don't have to unsolder the lead first. And most people do not want to unsolder anything. Sorry, I should have remembered that! You will still be in the ballpark without unsoldering, as Kris said.

(I always unsolder and put the pickup on an impedance bridge with a sweep frequency oscillator and a spectrum analyzer)