2 volume knobs - LP style or J-Bass style?

[Mixolydian42]

I was recently wondering something... On a Les Paul, if you put the pickup selector in the middle and turn the volume on one pickup all the way down, both pickups are silent. On a Fender Jazz Bass, if you turn one pickup all the way down, you still hear the other.

 

Anyways, today I looked at the schematics and figured out why this is. On a Les Paul, the 1st lug on the pot goes to the pickup, the 2nd lug goes out (to join the other pickup), and the 3rd lug is grounded. This means that, when the volume is all the way down, the output lug and ground lug are essentially connected, and so you get no signal at all because the other pickup's signal also runs through this connection to ground. On a Jazz Bass, on the other hand, The pickup is connected to the 2nd lug, with the 1st lug going out and the 3rd lug grounded. This means that, regardless of the individual pickup's level, the output signal will have 250k to ground, and isn't going anywhere.

 

My question is this... why do they do it one way or the other? Jazz Bass-style seems to make a lot more sense to me, yet guitars do it the other way. Is it just because most guitar players like the way the volume controls interact on a Les Paul? Or are there any tonal advantages to one or the other?

[laidback]

The pickups can be wired as you describe, or you can wire them so the volume controls are independant of each other. It's a simple mod, just move a couple of wires. Check out some of the pickup wiring sites for details.

 

 

 

 

I was recently wondering something... On a Les Paul, if you put the pickup selector in the middle and turn the volume on one pickup all the way down, both pickups are silent. On a Fender Jazz Bass, if you turn one pickup all the way down, you still hear the other. Anyways, today I looked at the schematics and figured out why this is. On a Les Paul, the 1st lug on the pot goes to the pickup, the 2nd lug goes out (to join the other pickup), and the 3rd lug is grounded. This means that, when the volume is all the way down, the output lug and ground lug are essentially connected, and so you get no signal at all because the other pickup's signal also runs through this connection to ground. On a Jazz Bass, on the other hand, The pickup is connected to the 2nd lug, with the 1st lug going out and the 3rd lug grounded. This means that, regardless of the individual pickup's level, the output signal will have 250k to ground, and isn't going anywhere. My question is this... why do they do it one way or the other? Jazz Bass-style seems to make a lot more sense to me, yet guitars do it the other way. Is it just because most guitar players like the way the volume controls interact on a Les Paul? Or are there any tonal advantages to one or the other?

 

[WRGKMC]

On a guitar it makes it fast for turning down both pups if its LP style.

Keeps you from having to fiddel with 2 knobs to cut the volume completely off. Its also a blend thing. If you have balanced pups theres less and less effect the blend of the two has on eachother. By the time you take it down to 50% (without a trebbel bleed cap) theres hardly any tone changes at that point. If you switch to that pup at 50% the volume is going to drastically drop so the signal grounding LPs use is benifical as a dual tool especially to kill high gain and completely remove hum. Fenders often had single volume controlls like the strat and tele, but the Jazz Guitar and a few others like the Jaguar i think has signal pass volumes. Rickenbacker did too. They got around the cutoff problem with a master volume on many of their guitars. They used the individual pup pots for sound blending.

[Mixolydian42]

After looking at the schematic again, I've realized something. With LP style, the load on the pickup is 500k at all times, but with J-Bass style, the load on the pickup goes down as you turn the volume down. Doesn't this mean you'll lose a lot of treble?

 

 

They got around the cutoff problem with a master volume on many of their guitars. They used the individual pup pots for sound blending.

 

 

Yeah, my Les Paul is actually wired with the volume controls as neck and master. That way I essentially have a blend control and an overall volume control. I lose my bridge volume control, but I think I'd need it because I don't see when I'd ever want to have my neck pickup set louder than the bridge, especially since my neck pup is hotter than my bridge pup in the first place. I'm thinking J-Bass style for my neck volume control might be better, though.

 

 

If you switch to that pup at 50% the volume is going to drastically drop so the signal grounding LPs use is benifical as a dual tool especially to kill high gain and completely remove hum.

 

Not sure I follow... so lets say you had identical guitars, except one with JB style wiring and the other LP style, and you put them in the middle position and set the volumes such that they blended the same, then if you switched to the neck only, one guitar would lose a lot more volume than the other would?

[WRGKMC]

Let me try to explain a littel better.

A balanced set of paul pups (With a proper height adjustment) will have equal volume on all 3 switch settings. The tone changes/blends will occur within 20% of the knob turn say 2 numbers from 10 to 8 on either one knob. (You could turn both down 20% and you'd be back to having equal volume for both pups at less volume).

The way I set mine is to turn the neck pup down 10~20% which has a nice tone. I can switch to the neck and have a clean rythum, switch to the bridge for driven lead and have it set in the middel for something in between. At the end of a song I can wang the neck pot down and it kills everything smoothly. Keep in mind I'm talking about a guitar with some drive on the amp. If I were to just stop playing there would be string noise and oscillating strings happening and I may not be in front of pedals to silence them so the knob cuts the sound completely.

 

Now if I set the Neck pup to 50% its output would have no blend with the Bridge. If I switched to the neck the sound would be pretty low and be a quite muffeled. The middel switch position and the bridge position would sound the same because theres hardly any signal from the neck to blend.

The oppisite would be true if the bridge pup was turned down in all these examples with a darker tone.

The two things to keep in mind here is with 500K pots and humbuckers theres a large reduction in volume in the first 2 numbers turning down and the last 2 numbers turning volume off. 250 K pots will reduce the overall volume greatly and have a faster jump in volume making it real difficult to blend accurately. A one 1 meg will require you to turn the knob 2x as far to get the same effects as a 500k and will abruptly turn off from 1 to 0.

 

Most of these effects will be the same with pots that arent signal grounded. The sound is passed through the pots as independant valves. You can turn one down and the other isnt affected.

As far as blending sound with the pups the 2 configurations have the same results. Some say the independant sound brighter but its irrelevant to me. My amps have plenty of trebble reserve i can use and I want pups to muffel up as they are tuened down so the guitar blends in the background of the other musicians. Another words I dont want my rythum to mask vocals and I want my leads to equal vocal level volumes.

 

One thing I did mention is the trebble bleeder(trebble pass) caps.

They can be used in either configuration to pass trebble.

Fenders commonly use them to prevent trebble loss when turning down the volume. It also prevents the fast dip in volume/tone as you turn down and makes the knob more linear. These can be added to a Gibson setup to do the same but the whole guitar tones drastically changes.

If you turn the neck pup down it will make the neck brighter than the bridge with the bass removed and trebble remaining.

I have a guitar wired like that through the tone control but it can be confusing playing live when you want a mellow sound, (If you switch to the neck and find it brighter than the bridge can confuse you making you have to look down and inspect your settings and make you look like a geek).

Trebble Bleed/pass caps seem to work best on a single volume guitar like a strat or tele but its neat to try out on dual volumes. You can hook 2 pups to a single pot through a bleeder and turn the knob either way to affect one pup or the other

[Mixolydian42]

Ok, I think get what you mean. So essentially all you're saying is that they're pretty much the same, except for the ability to kill the volume completely when you turn either pickup all the way down?