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Post by newey on Jun 8, 2010 23:32:23 GMT -5
OK, I know everyone's thinking, "another one of newey's hairbrained schemes that he wants us to vet . . ." Yep. But I've been intrigued with the 4-way (DP4T) Baja Tele switch for awhile now. It's not as complex or big as the Superswitch, but it offers independent wiring of the 4 positions, unlike the shorting Strat 5-way switch. Although it's only a 4-way, it seems to offer good possibilities for controlling 2 pickups. In the actual Baja Tele, Fender wires this switch to an S-1 pot to give series, parallel and OOP combos. I ditched the S-1 here, given that it's hard to acquire (and a bit fiddly to use, IMHO). So, I've been thinking of schemes using this switch. Here's one for a Strat-style guitar (3 pots are used), although it could be adapted elsewhere. A DPDT switch, which could of course be a push/pull on one of the pots, controls the mid pup on/off, and a separate mid volume gives the ability to season with the mid pup to taste. While the switching doesn't give "mid-only", turning down the Br/N volume pot will do so. Ideally, either the N or the Br pup would be RWRP so as to give hum-canceling combos on the 4-way. Three of the mid pup combos will then not be hum-canceling, but hey, you can't have everything. Of course, as with all my schematics, the first question is, does it work as intended? Second, at position 1 the neck pup is hanging from hot. I don't see any way around that. Is there? Third, will I get interaction of the pots with the mid on? Finally, anyone else have any Baja switch schemes, whether theoretical or actualized?
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Post by ashcatlt on Jun 9, 2010 0:30:21 GMT -5
1) Yep. Assuming you intend for it to work the way it does. It seems to correspond to your truth table. 2) Sure there is. Short it. SG had a picture of this up a while back, but you don't need it. Just look again. 3) Yep. Both volumes will act as masters. Also, as you turn down the one you intend as a master it will tend to isolate the middle pickup from the Tone control. I'm not completely sure why you're shorting the middle pickup when it's off. Remember that thing about the Conservation of Energy that ChrisK occassionally babbled about? I think you could use an SPST here to either connect the top of the coil or not. With the DPDT, you can actually disconnect both ends.
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Post by sumgai on Jun 9, 2010 1:19:33 GMT -5
newey,
Gotta stick it to ash for his answer to #3, he beat around the bush on that one....
If you turn either volume control all the way down, all output then resides at zero. Tends to make for either strong ears or long tears.
sumgai
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Post by newey on Jun 9, 2010 5:17:55 GMT -5
Thanks, guys!
I'll make the corrections for 1 and 2, those I got. Number 3, the volume control issue, I'm not sure if that's correctable. I suppose one way would be to scrap the tone control and give each pickup its own volume, but I don't really want to lose the tone control.
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Post by JohnH on Jun 9, 2010 5:30:24 GMT -5
Very good.
Another variant, probably ditching the two volume controls, wiould be to wire the Baja switch as you have it, to control N and B, then take all of that as a unit and combine it with M using an on-on-on toggle.
This could select, N,B combos (N,B combos)+M (N,B combos)*M
12 sounds in all, including a couple of mixed parallel/series ones
John
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Post by newey on Jun 9, 2010 5:46:48 GMT -5
Originally, I was thinking of using an on-on-on to give a "mid-only" setting (using a DPDT on-on-on), but I scrapped that so as to keep the stock look, if SW2 was a p/p pot. Using it for series on the mid would expand the palette, though. And if I use a master V & T, the extra pot space could accommodate the switch.
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Post by ashcatlt on Jun 9, 2010 10:30:20 GMT -5
I guess that one V is not meant as a master, but rather a B/N Volume. You could "reverse wire" both volumes to avoid that unwanted interaction. To fix the Tone thing, you'd have to settle for something like 50's style wiring with the T directly across the Jack, after everybody else meets.
We've discussed reasons to avoid both of these options. Looking again at the 50's wiring thing, I find myself wondering if changing the tone cap value couldn't help somewhat.(?). My kids have got my real computers busy right now, so I can't Spice it. Maybe later tonight.
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Post by newey on Jun 9, 2010 21:07:48 GMT -5
Ok, here's the revised version. I fixed the things Ash suggested- shorted the neck pup at pos 1, disconnected the mid at SW2, and reverse wired the volume pots. I did not, however, change the tone pot because I wasn't clear on exactly what to do there. Should the tone pot be reverse-wired as well? Does it matter, since it's only wired as a 2-conductor deal anyway? And I'm not clear on "wiring it across the output jack", as Ash suggested- I can see how to do that (I think), but I'm not sure how/why that avoids the problem. Would using a dual-gang pot, with one half for the mid, and the other for the B and N, wired before the reverse-wired Vol pots, help the situation?
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Post by ashcatlt on Jun 9, 2010 21:27:10 GMT -5
Would using a dual-gang pot, with one half for the mid, and the other for the B and N, wired before the reverse-wired Vol pots, help the situation? Ooooo, that's even better! It'll act mostly like a modern LP. When I said "across the jack" I meant just that. After both volumes. Since the "ground end" of your tone cap already goes to the jack sleeve, you'd just need to move the wiper to the jack tip and you'd be done. Then you'd have something similar to 50s wiring with the tone after the volume. While it does matter which end you ground for rotational reasons, you can't "reverse wire" the Tone circuit's variable resistor the way we do with a Volume potentiometer. In this case, there's only two connections and it makes no elecrical difference which goes where.
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Post by ashcatlt on Jun 9, 2010 22:17:58 GMT -5
Looking again at the 50's wiring thing, I find myself wondering if changing the tone cap value couldn't help somewhat.(?). Nope. Looks like changing the cap on the modern wiring can reduce the resonant peak and get closer to 50s wiring. When the tone control comes last, we can't get that resonant peak back.
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Post by newey on Jun 10, 2010 18:26:21 GMT -5
As suggested by Ashcatlt, with the tone wired across the jack: My suggested take, with a dual-gang tone pot before the volume controls: Now, which will work better, in terms of minimizing interactions of the pots? (I'm still not exactly clear on the differences between the "modern" and "'50s" pot wirings).
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Post by sumgai on Jun 10, 2010 19:34:22 GMT -5
newey, Forget about interactions for a moment, and look more closely at your 2nd version..... see that tone pot between the neck's hot lead and ground? What do you suppose is gonna happen as it's rotated, when B*N is selected, hmmmmm? Hint: both tone controls will affect the Middle pup the same way - unintentionally. Rule Of Thumb:Common ground connections for pickup negative leads are convenient only for parallel connections. The same rule applies to associated tone and/or volume controls. FWIW, I think that in terms of user experience (ease of use, easy to remember and quick to find the same tones again, etc.), your Version A is probably the best compromise. Yes, there is some concern over "50's wiring tone robbery", but again, we're compromising here. In essence, the moment you leave "master vol/master tone" territory, you complicate things - how much is up to you. I'm also inclined to leave things as is with Version A, and if the tone simply isn't acceptable, then try one of JohnH's JFET buffer amps. That should about nullify any anti-tonal interactions. HTH sugai
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Post by ashcatlt on Jun 23, 2010 23:50:03 GMT -5
...SG had a picture of this up a while back... And look what I found! This has come up a couple times recently, and nobody could remember where to find it. Maybe it should be in the schematics section?
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Post by newey on Jun 24, 2010 0:09:02 GMT -5
It should be in schematics. But is that SG's diagram? Who do we credit with it?
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Post by sumgai on Jun 24, 2010 3:28:28 GMT -5
It should be in schematics. But is that SG's diagram? Who do we credit with it? You credit anybody who can prove that he (or she) has the original AutoCAD drawing on his/her hard drive. Seems to me there should be only one volunteer who can make that claim..... Tag! I'm it! ;D For future reference purposes..... the difference between ChrisK's AutoCAD output and mine is simple - he always used a fugly font from the early 1980's, and refused to update it. I always use a Windows TrueType font, which happens to run under AutoCAD just fine. Do you want me to re-post it there? It'd be my first, ya know! sumgai
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Post by newey on Jun 24, 2010 9:12:19 GMT -5
Please do so.
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Post by sumgai on Jun 24, 2010 19:04:48 GMT -5
Done. And only three years (almost to the exact day) after I first posted the original diagram. Sometimes I wonder if I'm properly motivated....... sumgai the gai who's all set to join the Procrastinator's Club - Real Soon Now
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