MusicMaster Bass Capacitor Help Needed

There's many tech heads here on TalkBass that will probably chime in and explain the cap weirdness in your bass. I'm seeing a .005 cap in your ground wire from the volume pot to the bridge. I don't understand that at all. Grounds are straight wire from point A to B.

Also seeing a .05 cap on the the tone pot that goes from ground to the 2nd lug, I don't understand that.

There are a ton of schematics on line. Since you are wanting to go back to the original DiMarzio wiring that you had before the import EMG. I guess that you are wanting a humbucker with a series/parallel switch. That should be pretty easy to find on line. Stick a cap of your choosing for the tone. Small values roll off less high end, big values roll off a lot. .050 is one of the most popular caps.

Should be easy to wire up like the original DiMarzio days.

As for understanding what your friend did, can you ask him? Otherwise, I'm sure someone here on TalkBass will respond.

 

There was a time when grounding the bridge and strings was considered as a risky "shortcut" to inadequate shielding. The .005 cap allows the feeble AC currents to be shunted to ground, but greatly lessens the risk of electric shock from a "hot neutral" situation.

The 0.02 cap on the volume acts as an "always on" treble cut. As far as the 0.022 and 0.05 caps on the tone control, I've never seen anything like that. Seems like a quasi-random attempt to tweak the travel or "voicing" of the tone control.

If you do re-install the DiMarzio, I'd just go with a standard P-bass wiring diagram, maybe 500 k Ohm volume and tone pots if you like a brighter tone.

 

I remember reading an article, I think in Guitar Player magazine, in which Dan Armstrong recommended adding that cap to reduce the chance of electrocution.

 

The .022 caps are both used to tame the highs from the pickup. The .05 is a typical tone control cap, while the .005 is to prevent death by electrocution while touching the strings, however it doesn't protect the musician if he should touch the control shafts or 1/4 plug barrel while kissing a microphone, or jamming barefoot on the back lawn, or the basement floor.

 

Original Music Master basses had a strange wiring setup. In addition to what would otherwise be a conventional Fender Volume-Tone .05 (old, .047 new) cap, many original Music Master basses had another .02 capacitor hardwired to ground to permanently take the top end off the tone. I repaired a friend's bass some years ago and I wrote out the wiring as I observed it. My hand-written diagram is attached.

 

Seems more like your friend was just trying things.

A humbucker is a separate case. Most benefit from using 500K rather 250K pots. But best bet is to start with the manufacture’s suggested wiring and component values, and then begin experimenting from there.

FWIW I’ve found that better than 75% of the time I end up liking the manufacturer’s suggested circuit best of all. Probably because they’ve already tried a bunch of circuit variations and identified the good ones.

 

It doesn’t really work that well in practice. The only real way to protect yourself in a scenario like that would be with a GFI in the circuit path.

There’s been some who have argued the capacitor trick is better than nothing. But the problem with that is how the false sense of security you get relying on an ineffective solution can lead to bad things.

 

The standard upgrade to Music Master & Bronco basses is a Seymour Duncan Cool Rails for moderate tone, and Hot Rails for more mids. As I understand the DiMarzio pickups, they are about the same.

 

I upgraded my Squier Bronco (similar to a Musicmaster bass) with a Dragonfire pickup. I got the idea from a thread that I read here on TalkBass. At the time, I got my Dragonfire humbucker for $35. The price is up now. Excellent pickup! Sounds very similar to a P Bass.

Here's my Bronco.

Dragonfire AR5s ~ Humbucking Strat AlNiCo 5 Rails Pickup, 1QTY Pos & ColorChoice | eBay