nikogo
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Post by nikogo on Apr 7, 2015 12:10:42 GMT -5
Please take a look at these schematics: The S1 switch (SP3T On-on-on) provides parallel, single coil, and series connection for the neck pickup. The S3 switch does the same for bridge pickup. The S2 switch connects a bridge pickup, both, or a neck pickup. It provides all together 15 combinations. The filter (connected in point F) could be based on a 250K linear push-pull with DPDT switch or based on a regular 250K pot and a separate DPDT 3 position (on-off-on) switch. In upper (on drawing) position the S5 connects 250K and C1 in a regular treble-cut filter. In lower position rotation of 250K pot to the left will provide bass-cut filtering, and rotation to the right gives a mid-scoop filter. The S5 on-off-on switch in the middle position gives no-load filter-less combination. Inductance L1 could be a 24VDC signal relay coil 2-3H for medium output HB. For high output HB L1 should be about 6-8H; a 48VDC coil or two coils in series. The C2 capacitor will be in 0.1 - 0.3 uF range and should provide with L1 resonant frequency around 200-300Hz. An excellent tool for finding a right LC combination is JohnH's GuitarFreak. The volume pot does not have tone compensation circuits to keep tone unaffected by volume pot, counting on buffer to reduce the cable capacitance effect. The buffer amplifier is well known Don Tillman's scheme with small modification. I use two 1/2AA size lithium 3.6V batteries to get 7.2V that last forever. To adjust the J201 drain potential to mid power voltage I had changed R3 to 360 Ohm. It also increased output signal which is good and bad. The down-the-cable distortion just sings, but very strong piezo-bridge signal could be clipped by buffer. The R5 added to reduce commutation noise. The S4 switch can save a show if the battery is dead. The compact buffer PCB can be 10 x 10 mm or less.
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Post by JohnH on Apr 7, 2015 16:28:29 GMT -5
Now I see what you have been up to! Looks good, a couple of comments:
For the no-load setting, an on-off-on would be better with the wiring shown.
Thats a neat buffer. It looks like it would start to crunch at moderate volume since it has some significant gain with that jfet. You can stay clean if you work the volume pot. But if you just wanted a clean x1 buffer with no gain, a source follower circuit using the same jfet can give you more headroom and lower output impedance for even less current draw. What output cap are you using? Its being loaded by the 47k resistor so needs to be big enough to avoid bass loss. The circuif as drawn has an output impedance approximately equal to the drain resistor 6.8k. So its good for driving long cables into high impedance inputs, (but not really low enough if you wanted to go straight to a mixer). So for that id suggest a 1M output tie down (instead of the 47k) and a cap of maybe 220nF or more.
Thanks for the GFreak plug.
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nikogo
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Post by nikogo on Apr 7, 2015 16:55:32 GMT -5
Thank you John. S5 has to be on-off-on. It is my typo. The ceramic capacitors in buffer are 10uF.
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Post by newey on Apr 7, 2015 18:47:06 GMT -5
Nice work, Nikogo! Have you built this scheme?
My only question mark concerns the On-On-On switches. You show black bars to indicate the internal connections in the center position, but the only On-On-On switches I've ever seen or used would be the opposite from what you show, assuming we're looking at the lug end of the switch. In other words, in the center position, you show bottom- right connecting to common, and upper-left to common. The ones I've used, it's bottom-left and upper-right to common.
Your wiring is right for the switches as you show them, but I'm concerned someone holding such a switch up to your diagram will wire it backwards.
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nikogo
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Post by nikogo on Apr 7, 2015 19:30:10 GMT -5
Newey, I did not pay attention to position of internal contacts while drawing the switches. Thank you for your comment. It really could mislead somebody. I have used that schematics except the tone filter section. In the guitar on pictures the tone section is approximately as in this schematics: guitarnuts2.proboards.com/thread/7439/400-fixed-tones-hh As you see, not only scheme is experimental. All switches are located on the upper rib side. From top to bottom: - rotary switch - bass cut potentiometer - neck switch S1 - pickup selector switch S2 - bridge switch S3
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Post by reTrEaD on Apr 9, 2015 7:23:32 GMT -5
Hello, nikogo.
I noticed both HBs use the Red/Green winding when in single-coil mode. If you change that so one of the two HBs has its Black/White as a single, you will get hum-cancelling when two singles are selected.
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nikogo
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Post by nikogo on Apr 9, 2015 20:59:17 GMT -5
Hello reTrEaD, I agree, and actually I did connect that way, but not because of noise. The Seymour Duncan Duckbuckers have each coil picking only from three strings. So with those particular pickups I cannot use all combinations. For single coil sound I use both pickups and the neck one works with D, A, E and the bridge one picks from E, B, G, giving quite nice sound. I do not remember why my recording was not updated. Possible because in the next scheme it was not important. There any single coil can be used and some combinations inevitably will be more noisy than others. Actually noise is not a problem in this guitar, that is opinion of my friend, Stratocaster and Les Paul owner, who was surprised with its quietness. OK, it is good time to correct the scheme. I opened the guitar and verified: Some poor dark pictures:
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Post by wolf on Apr 11, 2015 23:18:03 GMT -5
Those are nice looking guitars. Did you build those yourself? It seems as though you put a lot of work into rewiring that guitar.
Here's my most extreme guitar modification www.1728.org/guitar6.htm but that's pretty tame compared to your electrical grid.
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nikogo
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Post by nikogo on Apr 12, 2015 1:10:04 GMT -5
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a914man
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Post by a914man on Apr 22, 2015 20:53:23 GMT -5
Awesome work! Do you have any videos that demonstrate the different sounds?
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