Wiring circuit incorporating piezo pickup

[newbe]

Hi
I am new to this site so please bear with me
I am building a guitar from scratch with bits of any hardwood I can lay my hands on.
The guitar will be a stat shape but semi hollow.
I would like to incorporate a piezo pickup switchable into your circuit HHH Strat with series/parallel option for position 2 & 4 modified TBX Tone and Neck/Bridge Blend
and also incorporate a preamp if possible.
the design is beyond my ability but I can follow a circuit diagram.
Many thanks for any help you can give.



Link to HHH Strat

res.cloudinary.com/phostenix/image/upload/GuitarWiring/StratHotRailsSeriesParallelTBXBlend.jpg


I have not bought any hardware for the guitar yet so open to suggestions

[newey]

newbe-

Hello and Welcome to G-Nutz2!

Dec 28, 2020 4:51:45 GMT -5 newbe said:

I would like to incorporate a piezo pickup switchable into your circuit HHH Strat with series/parallel option for position 2 & 4 modified TBX Tone and Neck/Bridge Blend

I'm not entirely sure to which scheme you are referring. Please post a link to it so we all know what you're planning.

As for adding the piezo, is there a particular one that you have already bought? The piezo will probably need a preamp, most commercial piezo systems incorporate one. If part of the goal is to be able to use both piezo and magnetic pickups at the same time, you will probably have better results if both the magnetic and piezo pickups are run through the preamp.

You will also need to figure out how the piezo is to be switched on/off, and where to put the battery for the preamp. Since you are building the guitar body from scratch, plan now where you are going to put the battery and how you will access it

If you are new to guitar wiring, you may be better off to wire the HHH diagram first, get that all working as it is a fairly complex wiring scheme in itself. Then, once that is all "up and running" so to speak, then add the piezo in as a separate modification.

We can certainly help with a diagram to add the piezo, but we'll need to know more specifics about what you're planning.

[newbe]

res.cloudinary.com/phostenix/image/upload/GuitarWiring/StratHotRailsSeriesParallelTBXBlend.jpg

I have not allocated any space for the battery as yet
I have not bought any hardware for the guitar yet so open to any suggestions
I am currently making the jigs needed to build the guitar

Happy new year

[newey]

OK, that's a pretty elaborate wiring scheme, so I reiterate my thought that you should wire all that up first, get it up and workable, before you move on to adding the piezo.

In any event, since the S-1 switch is "spoken for", you're going to have to add another switch to add the piezo. The usual ways that these piezo/mag combo guitars as wired is:

1) Dual outputs, potentially to separate amps, or to separate channels of an amp. This could be via two output jacks, or one jack with stereo cable/jack, with a foot switch to toggle between piezo and magnetic pickups, or both. The advantage to this is that one can have the preamp in circuit with the piezo side of the equation, while the magnetic pickups can be un-preamped, since the 2 circuits are essentially separate. Useful for toggling between an acoustic-ish piezo sound and screamin' {insert fave pickup brand here) sound.

2) Single output, with either/or piezo/mag switching (potentially via a footswitch, again). This is simpler, as one has either piezo or mag, but never both at the same time. Advantage is, again, no need to preamp the mag pickups.

3) Piezo and mag integrated into same switching scheme, so that piezo and mag can be active together. Both piezo and mag pickups are buffered by a preamp. Various means of switching the piezo/mag pickups may be used, including blend controls.

4) Piezo and mag pickup integrated switching, but with only the piezo pickup being preamped. This can be done, but the mismatch between the piezo and the magnetic pickups is likely to make any piezo/mag combinations less than satisfactory.

As far as technology, I've never tried them (so this isn't any kind of endorsement) but Graph-Tech's "Ghost Saddles" seem to be about the most popular integrated piezo systems. For Strat-style guitars, the piezo elements are integrated into the bridge saddles, 6 individual elements. This also allows them to be used as a MIDI interface. If you choose to go that route, they have wiring instructions to mate their wiring into the existing wiring.

[newbe]

this is a lot to check out and I will have to do more reading.
I will keep the mag and piezo separate to keep thing simple as this seems the best option.
I will read up on Ghost Saddles but have never heard of them.
If possible do you have a supplier for the HHH Strat with series/parallel option for position 2 & 4 modified TBX Tone and Neck/Bridge Blend or a parts list and I will source these parts
I will do as you suggest and wire the guitar before the piezo is wired.
I have looked on the internet for piezo preamp and I will buy a complete unit rather than make one from a wiring diagram as long as it can fit in the space as I have some led lights to fit.
A lot of work in a small space.

[newey]

Dec 30, 2020 13:49:46 GMT -5 newbe said:

If possible do you have a supplier for the HHH Strat with series/parallel option for position 2 & 4 modified TBX Tone and Neck/Bridge Blend or a parts list and I will source these parts

The S-1 switch and TBX pot are Fender components. They are available from many different sources on the internet. The blend pot is a regular 500KΩ potentiometer, available from virtually all guitar parts suppliers or electronics suppliers. The 5-way "Superswitch" (a 4P5T lever switch)is an Oak Grigsby switch, also readily available from guitar parts websites. Similar 5-way 4-pole switches could also be used, such as the Schaller Megaswitch "M" model or the similar EYB switch. The pickups are of course your choice; the diagram shows Setmour Duncan "Dual Rails" pickups, but the scheme will be just the same with any 4-conductor humbuckers (although the wire colors may vary and will need to be translated to SD colors).

[newbe]

Happy new year
I would like to thank you for all the help you have given me and now I will buy the component pieces as your list

[gckelloch]

Dec 30, 2020 13:49:46 GMT -5 newbe said:

this is a lot to check out and I will have to do more reading.
I will keep the mag and piezo separate to keep thing simple as this seems the best option.
I will read up on Ghost Saddles but have never heard of them.
If possible do you have a supplier for the HHH Strat with series/parallel option for position 2 & 4 modified TBX Tone and Neck/Bridge Blend or a parts list and I will source these parts
I will do as you suggest and wire the guitar before the piezo is wired.
I have looked on the internet for piezo preamp and I will buy a complete unit rather than make one from a wiring diagram as long as it can fit in the space as I have some led lights to fit.
A lot of work in a small space.

I honestly wouldn't bother with Piezo saddles. You need an active preamp to mix with the magnetic pickups so the impedance is correct. Piezo's are also pressure-sensitive, so the transients are too punchy and with a phase quack sound. A much simpler and cheaper solution without needing an onboard preamp is A Wilde "Q-filter". The mid-dip with the very high peak it allows - above 10kHz in your parallel/split positions - will offer a very convincing acoustic tone without the drawbacks of a Piezo saddle system that doesn't pick up wood resonances anyway because the saddles are thick metal on a thick metal plate. No wood resonances will be heard through that rigid heavy structure. I have a Q-filter on my Parker NiteFly V1, and it's really nice. I replaced the stock passive Piezo saddle system (which just plain sucked). Turning the knob down just a few notches or so will also give those aggressive SD rails a more vintagey Strat tone. Mount it on a P/P pot if you want it disabled when not in use, or have it switch to a standard tone cap. I use a separate master tone knob on the Parker with a P/P pot that disengages both knobs when it's pushed in. It's pretty handy to set up a tone and switch quickly to no tone controls. You could even have it switch to a different master tone knob if that's not too many knobs. Push/Push pots are much quicker than Push/Pull, but somewhat delicate and can drive you crazy if defective, but I have two on the Parker that have been working just fine for 15 years.

[newbe]

After all the previous advice about piezo, I have a separate preamp that will be fitted in the guitar along with the power supply, 9v battery.
I would like to add two piezo but what configuration is best, parallel or series.
The effect I would like is a more mellow tone rather that harsh.
I will be mounting the two piezo in silicon for cushioning but I may be wrong in that so some advice would be nice on mounting them.
I have read a lot on the subject but its conflicting and I am now truly confused to what way to go for the wiring.
The reason for two piezo is at a later date I may decide to add switches to select one or both once I have worked out the switching sequence.
Its easier to install two now rather than taking everything apart and cutting and drilling a finished guitar.
I have a spot for the future switches that require very little work as all the work for the switches is to modify a cover that is already made and fitted and a little soldering.
By the way I am at the varnishing stage of the guitar.
Many thanks

[JohnH]

Ive played with piezos, just using elements from piezo buzzers rather than a dedicated guitar system, with a home-brewed preamp to suit it. I ended up with a serviceable piezo system mixed with magnetic pickups on a Strat-style guitar.

What do you have? Id say the effect of series or parallel is different with piezos compared to how it affects mag pickups. Series should be louder, but the tone may be very similar, or series may have a bit less bass (depends on the preamp). Unless you are using a commercial system and following its guidelines, Id suggest to allow for some experiments if you are doing a custom non-standard set up. ie, allow for setting things up in a temporary way that you can experiment with, and reckon on needing to change it before finalizing.

[newey]

I'm not trying to discourage experimentation, far from it. But I don't know that having two separate piezo pickups will do anything useful.

Mind you, I haven't tried it and I don't recall that we had anyone here do so in the past. But given how a piezo transducer works, I doubt having two would add anything.

We put multiple magnetic pickups on a guitar because their differential placement along the length of the string yields different tones. A piezo disc, OTOH, senses pressure through the body of the guitar, so having two won't necessarily give any different tone, the vibrations it senses will be the same although the amplitude of those vibrations may differ depending on placement of the transducer.

Mounting a piezo element to the body of the guitar tends to make the guitar body "active" in the sense that tapping the guitar will cause noise. Having two elements might worsen this without providing any benefit sound-wise. At least that's my thinking, but it is admittedly guesswork, never tried this as I said.

However, in a different context, I have played around with wiring piezo elements in different ways. Several years ago, I made up a few "Stompboxes" for an amplified foot-tapping to accompany one's playing. The box was a wooden cigar box with a piezo element mounted inside of it, and wired to an output jack and volume pot- there is an ancient thread around here somewhere detailing that build. But I did try using two piezo elements, also trying two different sizes of discs, wired in series and in parallel variations. I found that none of those variations made any real difference in the "thump" I was trying to achieve, so I scrapped all the series/parallel, multi-disc experiments and went with one piezo disc with simple wiring. But I will grant you that this wasn't any sort of a test of what one might get with the piezo sensing string vibrations instead of a foot stomping on a wooden box.

Also, a piezo element needs to be firmly mounted, so I think something more solid than silicone goop might be advisable.

[gckelloch]

Sept 5, 2021 16:36:48 GMT -5 newey said:

I'm not trying to discourage experimentation, far from it. But I don't know that having two separate piezo pickups will do anything useful.

Mind you, I haven't tried it and I don't recall that we had anyone here do so in the past. But given how a piezo transducer works, I doubt having two would add anything.

We put multiple magnetic pickups on a guitar because their differential placement along the length of the string yields different tones. A piezo disc, OTOH, senses pressure through the body of the guitar, so having two won't necessarily give any different tone, the vibrations it senses will be the same although the amplitude of those vibrations may differ depending on placement of the transducer.

Mounting a piezo element to the body of the guitar tends to make the guitar body "active" in the sense that tapping the guitar will cause noise. Having two elements might worsen this without providing any benefit sound-wise. At least that's my thinking, but it is admittedly guesswork, never tried this as I said.

However, in a different context, I have played around with wiring piezo elements in different ways. Several years ago, I made up a few "Stompboxes" for an amplified foot-tapping to accompany one's playing. The box was a wooden cigar box with a piezo element mounted inside of it, and wired to an output jack and volume pot- there is an ancient thread around here somewhere detailing that build. But I did try using two piezo elements, also trying two different sizes of discs, wired in series and in parallel variations. I found that none of those variations made any real difference in the "thump" I was trying to achieve, so I scrapped all the series/parallel, multi-disc experiments and went with one piezo disc with simple wiring. But I will grant you that this wasn't any sort of a test of what one might get with the piezo sensing string vibrations instead of a foot stomping on a wooden box.

Also, a piezo element needs to be firmly mounted, so I think something more solid than silicone goop might be advisable.

Then again, silicone might absorb some of the thump; although it might be better to just wire a cap in series to roll off the low end. Two Piezo's might make a significant difference depending on where on the top they are placed, due to varying resonance modes. Maybe experiment with taping them in different places to see what you prefer. Rolling the bass down on the circuit might be helpful for that too. Closed or semi-closed back headphones will likely be needed to discern the Piezo sound from the acoustic sound coming off the guitar top.

[newbe]

I will use a single piezo as suggested. It's to fit between two pickups but does need a small amount of trimming to fit.
2mm on both sides to create two flats.
Superglue may be the easiest solution as I already have some gel type.

[gckelloch]

Sept 6, 2021 2:39:50 GMT -5 newbe said:

I will use a single piezo as suggested. It's to fit between two pickups but does need a small amount of trimming to fit.
2mm on both sides to create two flats.
Superglue may be the easiest solution as I already have some gel type.

Still, it's really not possible to determine the Piezo or magnetic pickup sound unless it's sufficiently isolated from the acoustic sound coming from the guitar. The high end string noise from the neck alone can be louder than you might think. I wouldn't be wed to placing it between the pickups. There might be a spot on the top you'll like the sound of much better. Would you be able to glue it inside after determining that? I'm not sure how well super glue will stick to wood grain. It's really meant for surfaces without gaps. Titebond III might be a better choice. It doesn't get really hard though, so it may limit high end response. A Gorilla glue that works on wood and plastic might be best.

[newey]

Yeah, I'm not sure between the pickups is a good spot, as gckelloch said. JohnH did a DIY piezo install on a Strat-type guitar and mounted the piezo disc to the trem block, had good results with that placement. We've heard tell of people mounting the disc in the neck pocket as well, like a shim would be, so that the neck screws hold it tight to the body.

I'd plan to experiment a bit with placement as suggested.

EDIT: Here's a link to JohnH's "Adding a Piezo Pickup" thread, this might give you some ideas. Note that he mounted the piezo disc to a coin using epoxy, and used some plastic spacers for a tight fit behind the trem block. However, the sound clips in that post now all redirect to another of John's recordings.