A mistake in an SD schematic?

[Artie]

While I was trying to draw Holydirt a better drawing for this thread, I discovered, what seems to be a mistake in one SD's drawings:


2 Humbuckers, 2 Vol, 1 Tone, 3-way

Look at this close. If both p'ups are selected, essentially, the wipers of both volume pots are shorted together. So, if both p'ups are on, and one has its volume on zero, and one volume on 10, both p'ups are shorted to ground.

Am I seeing this wrong? I'm going to try to find a better way to do this, but I just noticed it this morning, and the family is headed down to St. Augustine now. I'll work on this when I get back.

Artie

 

[Zerberus]

That´s an inherent problem with 3.way toggles and 2 Volumes, every LP, SG and Flying v has it

If you can solve it, post how, I´ll be sitting here with a soldering Iron waiting

 

[Robert S.]

You switch the #2 and #3 terminals at the volume pots so that the pickups and not the switch gets grounded at zero.

The posted way is the way production Gibbys are wired, switching the terminals so that the switch does not ground is simular to the older, 50s wiring.

Too easy......

 

[Artie]

Thats true, but doing it that way means, as you lower the volume, you also change the tonal charateristics. At half volume, you essentially have a 250k pot, (if you started with a 500k).

That won't necessarily be a problem, just something one would have to take into consideration.

 

[Robert S.]

I have wired both ways and I didn't notice a huge difference in response or tone. What I did notice is that if you ground the pickups and not the switch you can get bleed through when one pot is on zero and the other is on ten, and it is majorly annoying to dial down a guitar in the mid position and not have the guitar shut down.

The vast majority of guitars I see using 2 HBs and seperate volume controls are wired like the SD schematic, but it works either way.

 

[HolyDirt]

Re: A mistake in an SD schematic?

Look at this close. If both p'ups are selected, essentially, the wipers of both volume pots are shorted together. So, if both p'ups are on, and one has its volume on zero, and one volume on 10, both p'ups are shorted to ground.

what would this do?

 

[jeremy]

no sound from the guitar