Proposed L2K wiring mods - seeking feedback

idoru · #1 07-14-2008, 06:59 AM

g'day all,

I'm still digging my Tribby L-2000, but I find myself a little underwhelmed by some of the available settings. I'm hardly ever using the passive or parallel modes - without a grub screw in the volume knob it's pretty hard to come back to the same volume after flipping those switches.

I've read a bunch of info on the various mods, so here's what I'd like to get out of my L-2000:

1) Fully passive, with 500k V & T pots to increase the brightness.
2) Single coil mode - preferably both options.
3) Series & "bass boost" series modes.

Pulling the pre-amp out will gain me some room for push-pull pots if need be, but I suspect I can get what I want if I change the pre-amp switch to something a bit beefier.

Is it possible to wire a 3-way switch with enough poles so that I can pick single(neck) / series / single(bridge)? If I have two of those plus the standard pickup selector, that would be a lot of options.

cheers,

c-

idoru · #2 07-20-2008, 08:29 PM

Nobody?

After a bit more reading, I'm now thinking along the lines of switching between Series/Single (outer coils), with an optional bass-boost mode for series. I can do this with the standard 2-way switch and a push-pull, allowing me to keep the pre-amp.

Here's the follow-on question: in terms of volume, series > parallel. So much so, that series passive is still louder than parallel with the preamp engaged. From my understanding of DC resistance, the single coil mode should fit between the two...

So, to those of you who have the single coil mod on your L-2000: how does the volume compare to other modes? If I can match passive series with active single more easily, then the preamp will stay.

cheers,

c-

DavePlaysBass · #3 07-21-2008, 12:25 PM

In series mode you get two voltage sources that add together. This is twice as loud or a 6dB increase from parallel. In series, the resistance of the coils really has nothing to do with the volume assuming you are driving a high impedance preamp.

In parallel you have two voltage sources as well but they do load each other down. Assuming each coil as equal resistance, you get 1/2 of each voltage source added together or a net of 1 coils' worth of signal. We will call that the 0dB point.

When you go single coil, you only have one coils worth of output. It is not loaded down by a parallel coil. Neglecting frequency response issues, this single coil level will also be at 0dB. If you run a pair of single coils (one in the bridge and one in the neck) you get the same result as parallel and the volume level is theoretically the same as a single coil.

There can be frequency / phasing effects where the two coils worth of parallel (or series) signals do not add completely. Some people have noticed that two jazz bass pickups full on has a scooped sound and may not be as loud as a soloed pickup. This is because of the phase cancellation at some frequencies. However, this is usually minimal. In short series is 6dB hotter than single or parallel.

idoru · #4 07-21-2008, 04:47 PM

Cheers Dave - that clears things up immensely, and explains why my favourite Jazz tones always have one of the volumes backed off a touch.

More pondering required - in the meantime I've got a BYOC Armstrong Twin to mod

[Edit] Forgot to mention - I just drilled a hole in the side of my volume knob for reference, I might slip a spare Gibson position indicator under it to make it easier to line things up.

c-

idoru · #5 07-26-2008, 04:18 PM

Back again - I've read the big wiring options .doc and I have a few questions:

Mr DavePlaysBass, did you ever get around to wiring one of those switches up for Single/Series?

Has anybody used the tone cap on a Parallel setting, in a similiar way to the Series "Bass Boost" mode?

I'd just dive in and start playing around (easy enough to get back to stock, after all) but this is my main gigging bass at the moment. Guess I need a spare

c-

sunbeast · #6 07-28-2008, 12:34 PM

I have my L2000 wired with a stacked volume (to eliminate the need for the pickup selector switch), and seperate series/ single coil/ parallel switches for each pickup (one where the pickup selector switch was). I chose inside coils for the single coil setting. I think the phase cancellation of the parallel setting makes it noticeably quieter than single coil, but also warmer sounding (as most of the frequencies being cancelled are on the treble end of the spectrum). I also switched 500K pots for both volumes and the treble cut (which is actually just a standard tone pot with a fancy name!). The tone pot is also a push/pull pot which changes the series setting to "single coil with bass boost" by putting the .1uf caps into the equation. I rarely use the preamp, but it is still intact and unmodified. Occasionally I flip it on for some major bass boost (its the older version of the preamp, which seems to add alot less high end than the newer ones I've used)...

The caps wouldn't work the same with parallel mode, because both coils would run in parallel through the caps, cutting treble from both (so it would sound basically like a tone pot with .1uf cap turned all the way down- ie really muddy), whereas in series only one of the coils is affected by the caps giving you the full signal from the other coil.

Since you are considering modifying the bass anyway, I highly recommend that you consider seperate volumes and coil switches for each pickup- it adds a whole array of different sounds (like- parallel neck pickup with "single coil with bass boost" bridge pickup, one of my faves at the moment!).

Karl

(

Quote:

Originally Posted by idoru

Back again - I've read the big wiring options .doc and I have a few questions:

Mr DavePlaysBass, did you ever get around to wiring one of those switches up for Single/Series?

Has anybody used the tone cap on a Parallel setting, in a similiar way to the Series "Bass Boost" mode?

I'd just dive in and start playing around (easy enough to get back to stock, after all) but this is my main gigging bass at the moment. Guess I need a spare

c-

millahh · #7 07-29-2008, 08:15 AM

Quote:

Originally Posted by sunbeast

I have my L2000 wired with a stacked volume (to eliminate the need for the pickup selector switch), and seperate series/ single coil/ parallel switches for each pickup (one where the pickup selector switch was). I chose inside coils for the single coil setting. I think the phase cancellation of the parallel setting makes it noticeably quieter than single coil, but also warmer sounding (as most of the frequencies being cancelled are on the treble end of the spectrum). I also switched 500K pots for both volumes and the treble cut (which is actually just a standard tone pot with a fancy name!). The tone pot is also a push/pull pot which changes the series setting to "single coil with bass boost" by putting the .1uf caps into the equation. I rarely use the preamp, but it is still intact and unmodified. Occasionally I flip it on for some major bass boost (its the older version of the preamp, which seems to add alot less high end than the newer ones I've used)...

(

Wow...that's an awesome setup. How close can you get to MM sound do you get running just the inner coils? I seen folks mention that the position is close, but never seen a comment on how close it sounds.

4Mal · #8 07-29-2008, 10:21 AM

In my L2500 there is an Audere 3ZB lurking in the cavity. I like the passive MFD tones the best - the extreme trele boost of the G&L pre has always been a head scratcher for me that and the 10db boost on a stick approach - what about if I only want 7 db ?

So my switches are 3 way zmode, Series/Simgle/Parallel for each pickup. Knobs are Vol, Mid stacked on Blend, Treble stacked on Bass - and it sounds great. MFD's & AUdere are a great pairing.

My .02 and worth every cent

idoru · #9 07-29-2008, 06:14 PM

Quote:

Originally Posted by 4Mal

I like the passive MFD tones the best - the extreme trele boost of the G&L pre has always been a head scratcher for me that and the 10db boost on a stick approach - what about if I only want 7 db ?

That treble boost yields one of my favourite tones: neck, series, treble + pick on an amp with plenty of low mid dialled in. Awesome modern rock tone!

When you think about it, wouldn't a boost to make up for the Series/Parallel difference of 6 db make more sense? I've run my "modded" volume knob (with a hole drilled in the side for reference!) at two practices, and while it helps get me closer, I overshoot the mark every time I'm not looking.

Last night's practice yielded a bit of a surprise: both pickups, parallel, active seemed to cut through better than the series mode on any pickup or mode. I have to investigate further - it might just have been that my levels were out of whack, as I was swapping between a BEAD tuned Jazz & the G&L all night, and only threw the G&L into para on the last song.

Also: you'll notice my sig mentions Tech 21. Since I got the G&L, I've taken to dialling my RBI's Blend off from 100% for the first time. It sounds better than my Thumb (it just doesn't sit quite as wellin the mix).

c-

sunbeast · #10 07-29-2008, 10:13 PM

Quote:

Originally Posted by millahh

Wow...that's an awesome setup. How close can you get to MM sound do you get running just the inner coils? I seen folks mention that the position is close, but never seen a comment on how close it sounds.

I've never owned an actual Stingray, so I couldn't do a side by side comparison, but I imagine it sounds pretty close. I find the G&L pickups to be a little more naturally aggressive to my ears than the Musicman pickups though...

Karl