Single-Coil Mod Question, from the Schematically-Impaired

takeout · #1 02-12-2009, 04:12 PM

I have a question regarding the "7. Parallel – Single Coil Inside – Series Mod (3-Position 4PDT)" mod, specifically as relates to the schematic. I'm trying to implement this on my Tribute L2K, but I'm somewhat schem.-challenged... so I'm having a hard time wrapping my head around a couple of the connections. I'm hoping you guys can clarify.

I've attached a "matrix" of the switch, as I understand it. With this in mind:

Regarding all the grounds - can those all just be jumpered to one spot on the switch (i.e. "A1")? Or do they all need their own wire to the back of the volume pot? It's already a rat's nest in there...

Regarding "C3" and "C4" - can those be jumpered to A3? Same reason.

This assumes that my bass was wired stock to begin with - I bought used, and have no idea if anyone has monkeyed with it. The stock switch wiring didn't much resemble the stock diagram in Dave's doc.

takeout · #2 02-18-2009, 04:56 PM

Bump - anyone?

sunbeast · #3 02-19-2009, 06:18 AM

As far as the shared ground thing- no. First of all, there should be a jumper between C1 and C2, as well as a jumper between C3 and C4 in your picture (these connections are what makes the "series" mode). The ground connection you are seeing at the C1/C2 connection is through a capacitor which your Tribute doesn't even have, and should be ignored (ditto with the attachment from the C3/C4 connection to the pickup selector switch). If you make those connections without the capacitors present, then the switch will not function correctly. To reitterate- put a wire connecting C1 to C2 and another wire connecting C3 to C4 (and ignore any other connections from those 4 lugs) and the rest of your diagram is correct.

The capacitors that are in the diagram are something used on early US L2000s and L2500s that made the "series" mode into a "single coil with bass boost" mode instead (they were only present on US models up through the mid or late 90s as far as I know). The tone is different, and the series mode is no longer humbucking with the capacitors installed (unless you have both pickups on). If you like the sound of "series" as it is on your Tribute then I wouldn't bother adding the capacitors... Leaving them out will probably make this mod a little easier for you, and adding them in later would be easy enough if you decided you wanted to try something new.

Karl

takeout · #4 02-19-2009, 10:26 AM

Thanks, Karl. So the A4 ground is the counterpart to the A1 ground, and needs to go to the vol. pot as well?

Your clarification helps a ton. Thanks again.

wyleeboxer · #5 02-19-2009, 12:02 PM

The capacitors that are in the diagram are something used on early US L2000s and L2500s that made the "series" mode into a "single coil with bass boost" mode instead (they were only present on US models up through the mid or late 90s as far as I know). The tone is different, and the series mode is no longer humbucking with the capacitors installed (unless you have both pickups on). If you like the sound of "series" as it is on your Tribute then I wouldn't bother adding the capacitors... Leaving them out will probably make this mod a little easier for you, and adding them in later would be easy enough if you decided you wanted to try something new.

Karl[/quote]

Hey Karl, Ive got a Tribute L2000 for a back up bass to my 95' L2000 which I run in series, both pups, passive and rolling off the the bass "only" about 30%. I do notice a difference with Tribute as far as tone with the same settings, does it make a big difference tone wise to add the capacitors to the Tribute, or should I just mess with the amps EQ more if I need to make the bass switch during a show?

sunbeast · #6 02-20-2009, 03:46 AM

I think it makes a pretty big tonal difference personally. I've got my L2000 rigged up to give me the option of series with or without the capacitors (using a push/pull tone pot)- normal series is very midrange heavy and sometimes kinda "honky" sounding, whereas the capacitors really do give the setting more of a single coil clarity but with a large bass boost. The catch 22 is that normal series cuts through a thick rock band mix a little better in some situations. I still use the capacitors more often than not though.

Installing the capacitors is really easy, as is taking them out again if you find you prefer normal series. I would open up your US L2000 to make sure it even has the capacitors before messing around with the Tribute. One thing that should be noted is that the capacitors make the series setting hum similar to a single coil, and they were always wired from the factory in a way that that setting still wouldn't be humcancelling even with both pickups on. In other words, if your 95 L2000 doesn't hum like crazy with both pickups selected and in series, then the capacitors probably aren't there. If it does hum like crazy, DavePlaysBass's wiring diagram in the links sticky at the top of the G&L Forum will show you how to keep the caps but still get humcancelling with both pickups on.

Karl

sunbeast · #7 02-20-2009, 03:49 AM

Quote:

Originally Posted by takeout

Thanks, Karl. So the A4 ground is the counterpart to the A1 ground, and needs to go to the vol. pot as well?

Your clarification helps a ton. Thanks again.

Those 2 grounds actually can be shared- early L2000s were wired so that there was a jumper between those 2 and then a wire from one of them to ground. It doesn't really matter if you wire them seperately or together in that situation.

Karl

DavePlaysBass · #8 02-21-2009, 02:05 PM

Sounds like you are getting good advice. As for grounding things, you can tie all the ground points back to a single place such as the back of a pot, or you can daisy chain them (daisy chain means you ground a point on the switch with a wire going to back of a pot and then you get your next ground connection by just running a wire from the closest ground point). I know there are a lot of people that will claim single point ground is superior. In these type of low current circuits, I am not sure that it makes a whole lot of difference. When you have circuits drawing lots of current, single point ground is good if the wires going to ground pose a voltage drop due to wire resistance and high current. However, in bass wiring, the currents are low relative to the wire impedances.

As for you stock wiring, I mention in section 2 of the document above that the Tributes are done quite a bit different. However, if you explicitly follow the wiring shown for the setup you desire, you will get the results. And you can leave out the capacitors and you will still get the three way with SC. The key is to understand the state of the switches in the diagram and just wire as drawn.

joyboy52 · #9 02-21-2009, 02:31 PM

Amen to that. Take a breath, take your time, follow the diagram, and it works like a charm. I've done it to all 3 of my G&L's . It's my go-to setting. Thanks again, Dave

wyleeboxer · #10 02-24-2009, 03:53 PM

Quote:

Originally Posted by sunbeast

I think it makes a pretty big tonal difference personally. I've got my L2000 rigged up to give me the option of series with or without the capacitors (using a push/pull tone pot)- normal series is very midrange heavy and sometimes kinda "honky" sounding, whereas the capacitors really do give the setting more of a single coil clarity but with a large bass boost. The catch 22 is that normal series cuts through a thick rock band mix a little better in some situations. I still use the capacitors more often than not though.

Installing the capacitors is really easy, as is taking them out again if you find you prefer normal series. I would open up your US L2000 to make sure it even has the capacitors before messing around with the Tribute. One thing that should be noted is that the capacitors make the series setting hum similar to a single coil, and they were always wired from the factory in a way that that setting still wouldn't be humcancelling even with both pickups on. In other words, if your 95 L2000 doesn't hum like crazy with both pickups selected and in series, then the capacitors probably aren't there. If it does hum like crazy, DavePlaysBass's wiring diagram in the links sticky at the top of the G&L Forum will show you how to keep the caps but still get humcancelling with both pickups on.

Karl

Thanks, yeah they hum on my US L2000, but I wouldnt trade it for less tone! And there is a big difference in tone in series mode between my Tribute and my US which just sounds like such a bigger animal.. almost to the point that the Tribute sounds more like every other bass out there (even in series)and not what G&L is really know for??