jediboab
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Post by jediboab on Jun 15, 2016 8:41:56 GMT -5
Hi guys,
I have a Les Paul with a Nashville Piezo bridge and was looking to have the following....
Volume 1 working as a volume for bridge pickup Volume 2 working as a volume for neck pickup Tone 1 replaced with a concentric pot that will operate as a volume for the piezo, and the other half used to split the coils (i.e. the more you turn it the more/less it splits the coils) Tone 2 replaced with a 3 way toggle DPDT that will switch between magnetic/both/piezo.
The 3 way pickup selector switch will operate in the same way (i.e. bridge/both together/neck)
Is this possible? If yes, can one of you cool guys out there advise me with any wiring diagrams, etc... that I would need to do this. (Also, when splitting the coils, any kinda mod that will allow the coils to be split without killing the volume too much)
If I need to drill a hole for the DPDT switch, and use the tone 2 hole for something, then so be it. But was hoping to try and get this working without drilling holes.....
Many thanks guys Bob
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jediboab
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Post by jediboab on Jun 15, 2016 8:53:32 GMT -5
Or, if easier, instead of the Concentric pot, a push push maybe, so when pushed down (coil split), and normal (piezo volume) Might be easier actually, as it will look nicer and I can use the knob I have already (plus, I can get a long shaft push push easier)
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Post by newey on Jun 15, 2016 21:44:00 GMT -5
jed-
Hello and Welcome to G-Nutz2!
Your LP already has separate volume controls for each pup, so this isn't really changing anything. The tone controls will need to be disconnected, of course.
This is doable, certainly. The switch will be the last thing before the jack, and will simply switch the outputs to the jack. However, you don't mention whether your piezo has an active preamp or not- most do. Combining active circuitry and passive is problematic. JohnH has an excellent article on adding a piezo pickup to a Stratocaster, and his advice is to make the whole shebang active, running both magnetic and piezo signals through an active preamp. This allows adjusting the relative gain of mag vs. piezo, and avoids the problems switching between active and passive pickups.
Now this:
Raises more questions than I have answers. First, what coils are we splitting here? Bridge HB, neck HB or both at once? Second, see above for the question re: active preamp. Typically, concentric pots have the resistance values of each half either the same (i.e. both are 250K or 500K, or some will have one-half be 250K and the other 500K. If the piezo circuit is active, you'd want a vastly different value for that half of the concentric pot- say, on the order of 10K or 25K- and for a variable coil split of passive HBs. you'd want around 250K. So, you'd have to find a concentric pot with a 25K/250K rating, which I doubt can be had unless it's custom made.
There are other ways of achieving what you want. But the basic problem is that, if the piezo is not actively preamped, it's going to be swamped out by the mag pickups as the relative volumes will be discrepant. If the piezo is active, then you have the problem of switching between active and passive circuitry, and still likely have a volume mismatch as well.
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jediboab
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Post by jediboab on Jul 5, 2016 6:12:32 GMT -5
Hi man,
Thanks for the reply.
Ok, 2 x volumes as they are... all good dpdt switch... all good
SO, am looking at using the remaining hole on the Les Paul and putting in a push push pot (or push pull) I am using a passive piezo bridge (Schaller Nashville), so when in the down position have it work as a master coil split for both humbucker pickups (so, as you turn it down, it will split each humbucker at the same time incrementally), and when in the up position, be used as a volume for the passive piezo bridge.
My tech has suggested that I would need a concentric pot to do this, but they are pretty hard to get decent knobs for and look a bit ugly (Ideally, I wanted it to look like a stock Les Paul bit with a switch in place of one of the tone knobs)
Do-able.... or, concentric pot needed>?
Cheers guys Bob
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jediboab
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Post by jediboab on Jul 5, 2016 6:13:45 GMT -5
Oh, the piezo is actually LOUDER than the mag pickups at the moment... (AMAZING bridge, and the tone..... oooft!!)
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Post by JohnH on Jul 5, 2016 16:49:55 GMT -5
I reckon you would need some active battery-powered stage to mix magnetic and piezo pickups. Something like this maybe: www.allparts.com/PU-1271-000-Bartolini-Buffer-for-Piezo-Pickup_p_3067.htmlA bit of research needed there: it talks about boosting bass on the piezo side. I see they also do one for bass guitars that does not boost lows. So how is the raw tone of the piezo? Or, you can build your own buffer with transistors or opamps, but that is a journey you may not want to take, particularly if a tech is wiring this for you. On an LP, you could have the preamp blend pot as one knob, and do a simple 3 -knob passive wiring for the magnetic system, maybe with a master tone control, or a master volume to save a knob. Coil splits can be with one or two push pull pots. One such can split both, but you may prefer independent splitting. Another trick that I like (its on my LP) is to wire a standard tone pot to also split the PU. At 10 it is split by 9.5 it sounds like a humbucker and below that it is a humbucker toned down. One needed per pickup, suggesting a 1V 2T arrangement for 3 knobs. For an LP, make sure any pot has a long enough shaft to go through the top. That may rule-out dual pots. My own travels into piezos were as noted by newey. It was a piezo made from a buzzer. It needed particular tonal tweaking through circuitry to get the sound right. Yours hopefully has a better natural sound. But I quite like the way the controls work on a 3 knob strat. I have a volume and tone just for magnetic (plus pickup switching) and a piezo blend knob. With mag volume at max, it fades from mag, blending through a mag-piezo mix, to full piezo. Or of mag volume is zero, it acts as a simple piezo volume. In practice, any mix can be set. guitarnuts2.proboards.com/thread/3718/adding-piezo-pickupThe other thing I put up was an active module that can be used to mix active and passive: guitarnuts2.proboards.com/thread/4595/active-pickup-blender-volume-module
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jediboab
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Post by jediboab on Jul 7, 2016 16:23:52 GMT -5
Hi there, I'm really just after 2 x Volumes as per standard Les Paul, 1 x 3 way toggle to switch between mag/both/piezo only and a spin a split that splits both humbuckers together....
I've had a tech try this and fail. We've got the spinasplit working (well kinda, as it doesn't really spilt till the knob is turned almost all the way off, and it's definitely a linear pot, weird...?), And the 3 way switches, but I can hear spillover of the piezo when the mag is on
If one of you wise dudes can email me a wiring diagram/advice on:
2 x Volumes working as a standard Les Paul 1 tone replaced with spinasplit mod that does both humbuckers together The other tone replaced with the 3 way switch.
That would be great!
Cheers group
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Post by newey on Jul 7, 2016 21:04:21 GMT -5
Do you have a diagram of what he wired? That might shed some light. A Basically, same question: How is it wired? Also possible that this could be due to a stray strand of wire shorting things at the 3-way switch. This particular dude isn't feeling very wise lately. And, we don't e-mail diagrams around here, we post them hereabouts, for others to review, learn from, and maybe someday build themselves. But let me see if I can pull something together for you. Might be over the weekend. Hopefully, this isn't one of those "I need it by 5 pm tomorrow so I can get on the tour bus to Omaha" deals.
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Post by newey on Jul 7, 2016 22:20:25 GMT -5
OK, so I gave myself a bit of a "fudge factor" on how long it would take for a diagram . . . Now, several points to make, before you get that soldering iron a-blazin': First, someone needs to check this. Another set of eyes is a good idea. Second, there is no piezo volume, since I was going from your last: I, personally, would want a piezo volume, and if you insist on having separate volumes for the HBs and on not drilling any more holes, then it's time to get creative on where to put a piezo volume. I'm put in mind of one of the "knurled wheel" pots, like those on a Fender Jaguar, and maybe it gets mounted to the round LP switch coverplate on the back of the guitar? (JohnH has posted photos of his LP switch cover, to which he mounted a pair of slide switches, that's what gave me the idea . . .) Third, I used SD wire colors, with grey subbing for the white wires. Your colors may vary. Finally, note that the "spin-a-split" is shown using a "dual-gang" potentiometer, which is essentially twin pots on a single shaft (so, not a concentric pot, and will take a std. LP knob.). Doing this allows you to split opposite coils (i.e., one slug coil with one screw coil) from the two HBs, thereby maintaining hum-cancellation as you turn down the knob. If a single pot is used, then you can only split to the same coil for both HBs, which won't be hum-cancelling. (and, yes, to answer your previous question, you'd need a concentric pot to add the piezo volume control- that's why I'd look elsewhere to add that.) EDIT:: Also note that the diagram omits the bridge ground wire, as well as frame grounds for the switches, etc.
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jediboab
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Post by jediboab on Mar 7, 2017 12:14:12 GMT -5
Sorry for the long delay, not checked in in a while!! thanks so much for this buddy, I ended up with a stacked hum in the middle (butchering my les paul by routing a single coil cavity in the middle), decent job, but after getting it all wired up, I'm not getting that "strat" sound any better than if I has just phased the hums and split em.....So will be going back to the 2 hums and original idea, so, your digram will be excellent for this!! (Not the arduous task of filling that single coil cavity!!) I have 1 mini toggle switching the mag/both/piezo, 1 volume for each humbucker, 1 push push pot splitting the humbuckers and engaging the middle in some variation), and the usual 3 way selector switch)... The way it's wired, when in down position on the push push, it's a standard les paul, when in up, the hums get split and the stacked hum gets added, so, split neck/split middle...middle on own... split bridge split middle)...volume drop is not ideal, so, I might need to have a FULL middle with the split hums...I "might" try this before taking it out and filling) Cheers Bob
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Post by newey on Mar 8, 2017 6:13:19 GMT -5
The guitar would probably look better if you just left the middle pickup in there, rather than trying to "fill" in the rout. To get a repair like that to look right will mean some refinishing work, and even then it will probably still be pretty obvious that it was filled in.
If the goal was to get Strat-ish sounds, a split HB coil is never going to sound exactly like a Strat SC. Using a single coil for the middle might get you closer, but then the issue of hum rises its head. If the volume mismatch is the main problem, by all means try the full middle. I've never found that splitting those SC-sized HBs to be useful, the individual coils are just too small.
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