Single coil mod

fender3x · #1 01-06-2009, 10:42 PM

I have been thinking about doing a single coil mod on my ASAT. Some folks seem to like the inner coil mod the best (Sunbeast and Daveplaysbass), perhaps because it comes closest to an L1K sound?

On the other hand it looks to me like the position of the outer coils is in about the same position as Jazz pickups...so I am guessing that mod has fans too?

I am thinking of doing the inner coil mod since (a) lots of folks seem to like the L1K sound, and (b) I have an SX Jazz with Model J pups...and I can play that if I want to have more of the J-bass sound...

Still, since I can't a/b the settings in advance, I am curious what others think who've had a chance to hear the mod. Ears are better than logic, I figure ;-)

sunbeast · #2 01-08-2009, 04:42 AM

I only tried the outer coils for a short time in my old L2500, and have considered trying them again sometime in my L2000. You can get a close-ish idea of the differences by lowering the pickups a bunch and then raising all the polepieces on only one coil as high as possible- in parallel it'll sound more like the single coil tone as the coil with the raised poles will be much louder than the other coil (series has a completely different tonal character). I measured the poles once on a 60s-style jazz and compared them to my L2000- the neck pickup was a little closer to the neck than either neck coil and the bridge pickup was basically right between the 2 bridge coils.

Karl

francisl2500 · #3 01-08-2009, 06:50 AM

Karl.. don't whant to hijack this thread but ... with all the tips you gave for everybody your name should be Sound beast . Many thanks Karl

Francis

sunbeast · #4 01-08-2009, 11:46 AM

Seriously, all my friends just think I'm crazy tinkering with all this stuff constantly (and I really can't argue with that)- Talkbass gives me a place to converse around other crazies with similar eccentricities as myself.

So, thank YOU!

Karl

(if only I could spend as much time PRACTICING MY INSTRUMENT, I might actually be a decent player too!)

fender3x · #5 01-08-2009, 08:42 PM

Yeah, I have also really appreciated the benefit of your experience! OK...so how about this to converse about...

I *think* I have finally figured out the mod I'd like to do...

Bridge switch: no change from standard.

Middle switch: 3 position DPDT that puts the bridge pup in serial/SC/parallel.

Neck switch: 3 position DPDT that puts the neck pup in serial/SC/parallel.

Bridge pot: No change from standard

Middle pot: Change to stacked master vol/treb cut.

Neck pot: Change to 3 position DPDT rotary switch.

I figure that if I put a rotary switch in the spot where the neck pot is now, I can put a chrome knob on it and it won't change the aesthetics.

So far, the problem with this idea is that I have not been able to find a rotary, 3 position, DPDT switch. Anybody know a source?

millahh · #6 01-09-2009, 07:36 AM

Quote:

Originally Posted by fender3x

So far, the problem with this idea is that I have not been able to find a rotary, 3 position, DPDT switch. Anybody know a source?

If it exists, Digikey probably has it.

fender3x · #7 01-09-2009, 10:00 AM

Quote:

Originally Posted by millahh

If it exists, Digikey probably has it.

That's probably true, but I can't figure out which one to order. I want a rotary switch that works just like an on-on-on, 3 position DPDT switch. There are so many options with rotary switches, that I'm not sure which one will do the job. Hoping for suggestions from the hot-rodders here ;-)

fender3x · #8 01-10-2009, 08:54 PM

fender3x · #9 01-12-2009, 09:48 PM

OK...since I got no takers on that question, here's another...

If I do a stacked vol/treb pot, I need to find a stacked 250K/250K pot right? So how come all the stacked pots I have located seem to be 250K/500K?

Ken Baker · #10 01-12-2009, 11:40 PM

Quote:

Originally Posted by fender3x

OK...since I got no takers on that question, here's another...

If I do a stacked vol/treb pot, I need to find a stacked 250K/250K pot right? So how come all the stacked pots I have located seem to be 250K/500K?

Yeah, a 250/250 is going to be nigh-onto impossible to find. There are a couple ways you can go with this:

1. Use the 500K pot for the volume and the 250K for the treble cut. It'll work, but the 500K may darken the over tone a tad.

or...

2. Solder a pair of 1M 1/4 watt (that 1 megohm, quarter watt) resistors across the outer legs of the 500K pot. This will yield a pot with an equivalent resistance of 250K. It will sweep end to end from zero ohms to 250K ohms. The difference is that the resistance curve will be a bit other than audio taper, but it isn't a difference you're likely to hear. For the sake of accuracy, use this one for your volume pot and he real 250K for the treble. As a volume control, you just won't notice the curve difference.

BTW - this is how I got a matched 250K dual-concentric pot when I did my SB-2 tone pot mod. Started with a 500K dual-concentric control and added the resistors as described above. Worked like a champ.

Ken...

sunbeast · #11 01-13-2009, 12:16 AM

Unless you are severely opposed to changing the tone at all, you can just use the 250K/500K pot. Using the 500K for Master Volume or tone would not affect the function and just result in a slightly brighter sound (I'd recommend it for the tone control myself, as a simple passive tone control such as the one on the G&L will always be passing some treble to ground through the capacitor even when turned all the way up- less so with a larger resistance pot). Turning the tone down slightly will more or less compensate for the slight difference in tone.

Also, I was fairly sure that stacked 250K pots were more readily available these days- in fact I just found a couple for sale by Google-ing "250K/250K stacked pot". Not CTS brand, but again- you can use the CTS 500K/250K in this application with no problems!

I don't specifically know the part # for the rotary switch you are searching for, as most rotaries for guitar application are 5 or 6 postition varitone switches, but a pickup selector is a very simple circuit that can probably be wired onto just about any 3-position on-on-on rotary switch. Just find one with the right pot shaft diameter for your bass and then post a link here (or even better yet- on the Pickups and Electronics Forum)- I'm sure somebody will be able to tell you how to wire it at that point.

Karl

fender3x · #12 01-28-2009, 09:05 PM

I thought of another way I might try the mod... Suspect this would mean getting rid of the caps.... Sadly, tho, no one has commented

5 way switches mod...

Will be interested to see if anyone has wired a 5 way switch this way before... Would not have thought of it, but for the suggestion about a 5/6 way switch....

**Freddels** · #13 01-28-2009, 09:42 PM

I want to do the single coil mod to my ASAT too. I did some measurements and if I did the inner coils, the the bridge pickup inner single would be approx in the Fender Jazz 60's position. Outer would be approx in the 70's position.

How about inner on the bridge pickup and outer on the neck pickup? Is that doable?

sunbeast · #14 01-28-2009, 09:51 PM

It is possible, but you wouldn't get the Jazz style hum-cancelling with both pickups on full (they would be hum-adding instead). The only way to use inside and outside and have them still be hum-cancelling woul be to flip the coils on one pickup, which would require popping them out of the pickup case and rotating 180 degrees...

Karl

**Freddels** · #15 01-28-2009, 10:23 PM

Quote:

Originally Posted by sunbeast

It is possible, but you wouldn't get the Jazz style hum-cancelling with both pickups on full (they would be hum-adding instead). The only way to use inside and outside and have them still be hum-cancelling woul be to flip the coils on one pickup, which would require popping them out of the pickup case and rotating 180 degrees...

Karl

Thanks. That wouldn't be worth it. So it'll be inner or outer for me.

KPJ · #16 01-29-2009, 06:15 AM

Fred, are you going to do the mod or have someone do it for you? I'm thinking of doing the single/series/parallel mod with a 3 way switch on my ASAT. Is that the mod you are thinking of going with?

**Freddels** · #17 01-29-2009, 03:55 PM

Quote:

Originally Posted by KPJ

Fred, are you going to do the mod or have someone do it for you? I'm thinking of doing the single/series/parallel mod with a 3 way switch on my ASAT. Is that the mod you are thinking of going with?

Yes, that's the one. I'm an electronics dolt so I don't know if I want to do it myself or not. Of course, I'm also a very good monkey-see, monkey-do so if there was a youtube vid or if I watched someone do it. I'd be able to do it no problem.

KPJ · #18 01-29-2009, 06:50 PM

Maybe we can get a 2 for 1 deal. I'm ok with electronics but those contacts on those switches are TINY!

fender3x · #19 01-29-2009, 10:37 PM

OK...no takers on my previous query so here's another little brain-fart:

I think this might work... Take DavePlayBass's "7. Parallel – Single Coil Inside – Series Mod" adding the 4PDT switch. Add a second dpdt switch like this... (sorry about the ugly drawing)...

Put the 4PDT switch in "parallel".

If you put in a two position DPDT switch (eg with a push-pull pot), the down position does the normal parallel mode. The up position would be SC-outside.

If you add a three-position on-on-on DPDT instead of a two position... In position 1 you'd get normal parallel. In positon 2 you'd get the neck coil only in the neck pickup, and both coils in parallel in the bridge pickup. In position 3 you'd get SC-outside.

I am pretty sure to make it work you'd need to pull the caps...but here's my question... Did I get this right? Or did I screw up the wiring somewhere?

flash99 · #20 01-30-2009, 01:10 PM

Quote:

Originally Posted by Freddels

Yes, that's the one. I'm an electronics dolt so I don't know if I want to do it myself or not. Of course, I'm also a very good monkey-see, monkey-do so if there was a youtube vid or if I watched someone do it. I'd be able to do it no problem.

If interested and you are near NYC or want to ship your bass here, we are offering the single coil mod at Guitar Man. The work is all done by Mas Hino.