adding a neck J to my ATK305, going passive?

I have two ATK's, both of which I enjoy. One is my 750KA, awesome, fun to play, great neck but only 4 strings. I also have a 305 which I use more often, as I find myself using the low B string, like, all the time. But I really enjoy the added tonal options of a neck J pickup like on the 750. It adds a lot more depth to the tone, IMO.

So I'm thinking I'll add a J to the 305, and make it a poor man's 55-94... I have a few questions though and I'd like some opinions.

1) What is the optimal placement for the J pickup? How would I best measure and place it?
2) What 5-string J pickup would suit the ATK's natural aggressive characteristics?
3) Can I still use the pickup selection switch for the triple coil pickup if I go passive? The J/MM sounds on my 750KA are dead on, and I'd like those options for my 305 too.
4) I'll have 4 knobs: v/t/v/t? or v/v/mv/t? or v/v/t?
5) Would it be better to stay active and get a new preamp or something?
6) How likely is it that I will destroy this bass that I love?

After doing some more reading, I think I've settled on the dimarzio ultra jazz 5 for the pickup. I'm gonna need to cut a new pickguard...eh.

My only real burning question is what the best wiring would be, assuming I go passive. (the preamp is OK, but it's not amazing and I don't use the EQ hardly ever). I might just take it apart this weekend and wing it.

That's a great idea. I could just throw in a volume knob ( i keep my tone full at all times anyway) and stack the B/T pot...hm. i was hoping to do as little woodwork as possible- the stacked pot idea will definitely be implemented. a blend knob would be cool too.

I have no strong feelings towards the preamp- i could live without it, i can live with it. I guess i just have it in my head that a passive wiring setup would be easier somehow.

Could i patch the J pickup in with the bridge pickup signal before the preamp so that my EQ settings work for the neck pickup as well? and if so, could someone tell me a reasonable way how to do so?

i just understood your post better, Justyn. stacking the MV with a blend pot makes more sense overall. As long as the output levels are about the same that would probably be the easiest way to go. wow i feel silly that i didn't fully understand that before. it must be bedtime.

so i got the pickup in the mail (bestbassgear-FAST shipping!) and i found out that the pole pieces don't line up super excellently- the string spacing on this bass is so tight! so i guess i am going to go the angled route and end up with a kinda P vibe.

Query to anyone who might be reading: Should I put the G-side closer to the bridge (a la P) or for a brighter tone up top, or put the B-side closer to keep the B from being super heavy sounding?

and upon further inspection of the preamp i found that I have the old style PCB setup going on- the pots are on the board and all that. so this confirms my original idea that it will be a heck of a lot easier to just wire it passive. I also am going to reverse the 3-coil so that the single coil setting is closer to the bridge and not the neck, since my new neck pickup will cover a better "P-imitation." that way i can get some harmonics clarity when i need them.

any thoughts? anyone?

no one has anything to say about this huh. well i will take photos tomorrow and document this project anyway. that'll show 'em!


*ba-dum-ching*

thanks for the tip. I did use my 750 as a template for placement. i put the center of the pickup at the same basic location as the 750's J. I put it at a slight slant, kind of like a P setup. Actually the way the pickup is wired internally will make it quite a bit like a P5. The bottom three strings are one coil, and the top two are another. It is a bit closer to the neck than a standard P, but it will give me a nice super deep tone.

I did the routing yesterday. I practiced a few times on some scrap wood until i felt comfortable enough. it's not the cleanest job, but the pickup fits in snugly. i shielded the cavity, and placed the pickup in there, screwed it in and all that. I need to get some pickguard material and cut myself a new PG- I'm not too worried about that. Anyone know where I could get some PG material locally? It doesn't have to be fancy,flat black would work. Or must I order online again?

My pots, cap, and thumbrest shipped today from guitarpartsresource, so next week when I get them I will get to wire it up and go! I have always wanted a thumbrest on this bass, since there really isn't anywhere to put a thumb, and I'm not as comfortable with the floating thumb technique.

I also reversed the ATK pickup so that when i do the single coil setting it will activate the coil nearest the bridge, and not the neck. This will help me cut through on the songs where I use harmonics, and give me a closer J sound with both pickups engaged [well, i guess it will be kind of a P+J]. The MM setting should be unaffected.

anyway, once i find a camera i will take some photos of the finished product! I will post some clips of the new pickup settings as well. I'm pretty stoked. The woodworking had me the most worried, and it went off relatively smoothly.

since everyone is dying to know...

i put the pickup in and wired it up yesterday. CTS pots- 500K for v/v/t, 1M for the MV, and an orange drop .1uF cap. I left the switch in for the 3-coil pickup. I couldn't reverse the pickup like i wanted since the wire was too short to reach.

But it sounds AWESOME. Exactly what I was hoping for. I took a risk on this project, but I'm super pleased.
The neck solo'ed sounds a lot like a deeper than average P due to the slant and the placement nearer the neck, the ultra jazz fits the character I was going for wonderfully. Really bloomy and heavy sounding.
With the single coil on the bridge and the neck at the same time, it's like an extra-deep jazz, with a REALLY crisp top end.
The bridge humbucker with the neck going sounds mostly like the humbucker, but with an added depth that it was missing before.
And of course, I have all the same solo bridge settings as before (no lost functionality in the switch!). So all in all, I'm shocked that everything worked out EXACTLY as I wanted. I was doing some *ahem* educated guesses with the wiring, but it all panned out on the first try!

I highly recommend going passive on the ATK. With some good pots and a nice cap, I can get even more brightness than before (!). No batteries needed! The neck adds the depth of tone that the bass was kind of lacking before. It sounds much better slapped now (with both pups on/ATK single coil mode), and the neck pup solo'ed setting is most righteous for deep crispy pick playing. The tone knob rolled all the way off sounds SUPER dark but retains a nice amount of clarity- excellent for dub or some old-old school funk. Plus I've got the humbucker, if I want that midrange snarl that the ATK is known for.

I decided to hold off on the thumbrest. The neck pup works pretty well for that. I might throw it on another bass.

I used it at band practice last night. SO AWESOME. At one point I used the neck solo'ed -> Russian Muff -> amp and the keys player was shocked at how amazing and bloomy and fuzzy it sounded. I've used that setup many times before but the new pup just shined through the muff. I still need to cut a new pickguard to make it look super professional again, but I am a happy camper right now. I'll post some clips and photos once I get a recording setup going again.

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voila! after i cut me PG it will be prettier

It has a surprisingly different character from the 750 for a few reasons:
1) Dimarzio Ultra Jazz instead of whatever is in the 750
2) Slanted neck pickup (gives a much better P approximation IMO)
3) Passive setup- no more active EQ.

With the 500K pots/.1uF cap, it can get a really bright tone that still has a lot of fundamental. I think it's naturally a lot brighter than my 750 now. The orange drop tone cap is excellent- I buy the hype now. I am finding I really prefer the passive setup- it kinda clears up the tone. It's not that the stock electronics are bad, per se, but they don't seem to add anything all that awesome. I've been considering making my 750 passive as well, but I would have to figure out that switch wiring.

For suggestions? Take your time, measure twice cut once, etc. etc. If you have a chance to try out multiple pups that would be cool. I bought mine new, but I am very pleased with the choice. Evidently, I did not think about the 16.5mm spacing when I bought the pickup so I had to put it in at a slant to get the pole pieces to line up wiht the strings. Not a big deal, but it threw me for a loop. I've seen some people do mock up rigs to figure out ideal pup placement but I just used my 750 as a rough template. The middle of the J5 is 5.5cm from the ATK pup, which is the distance the 750's J is from the ATK pup in that bass. It's closer to the neck than a P, but it adds that bassiness that the ATK doesn't really bring on it's own.

All in all, it's got me second guessing my 750...although the 750's 19mm string spacing is much easier to slap on. I think a 700 with a P thrown in there would be sweet.

yeah MV+V/V/T+3way was the way i did it. The switch isn't powered or anything, so it works great. The MV has recently been made redundant by the fact that I got a volume pedal, but that was a recent chance freebie. I do get a TINY bit more hum out of it, but I think it's more from the uneven shielding job I did. Generally it's less than it was when I had the treble cranked on the 3-band EQ. Sometime I will flatten out the cavity completely and re-shield everything. I will probably shield the control cavity/ATK pup cavity too, as right now those just have that conductive black paint on it.

you could check the ATK club to see if anyone has put in a P on their ATK, but I don't recall seeing anyone having done that. The MM/P combo is pretty rare. It's just a thought- I think it could be a cool punchy sound.