After a somewhat casual search, I cant find any mention anywhere of how this pickup technology actually works. Only someone wanting to sell me something.
Background is I purchased a "parts / repair" instance off ebay. A little saddle mounted affair with a coin cell battery. I figured I could always make use of the pre-amp part, if I was not able to repair it. I could not, it was mechanically damaged.
On inspection of the battery powered circuit, it's entirely passive. No op-amp, no transistor - nothing except a few two "pin" SMD components, the jack, the battery holder and a miniature volume potentiometer.
This got me curious, so I started to strip away the heat shrink cover over the pickup rod. There's a couple more SMD parts there at the preamp end, apparently a resistor and capacitor in parallel. The element itself looks like a "Flex-Print" type of Kapton based material. I could not scrape away any coverage to get probe contact to see if the element - what's left of it - is resistive.
Whatever it is, it must be one tough little strip of material. The instructions came in the box and the pickup routing is insane. The majority of the strip goes underneath the bridge in the saddle slot as usual. Then it takes a hard right angle turn, up the side of the bridge, which you're supposed to shave the end slightly to accommodate the element thickness. Then a second, nearly right angle turn to the battery / circuitry enclosure, which is stuck onto the saddle with double sided sticky mat.
No piezo pickup, constructed of six individual bars of piezo material held in conductive channel, could mechanically take such an arrangement. So what is it?
FWIW Shadow is still in business and will sell just a "NFX" bridge pickup element for about $45, shipped. That's entirely reasonable, but like many engineer / musicians (I'd bet), I want the "lecture on Heaven" before walking through that door. Like a clear description of the operating principle, i.e. how it's able to work with just a voltage and passive support circuitry. How it can withstand right angle bends without breaking immediately?
Additionally, I have a Kala guitar with a Shadow pickup system. I bought it at a yard sale with the saddle ripped off the top. I've reglued the saddle twice and had it explosively come off, for a total of 3 times its pickup element has got the tar beaten out of it. It still works, which is the only clue I have suggesting that it too is of the unknown "NFX" technology.
Background is I purchased a "parts / repair" instance off ebay. A little saddle mounted affair with a coin cell battery. I figured I could always make use of the pre-amp part, if I was not able to repair it. I could not, it was mechanically damaged.
On inspection of the battery powered circuit, it's entirely passive. No op-amp, no transistor - nothing except a few two "pin" SMD components, the jack, the battery holder and a miniature volume potentiometer.
This got me curious, so I started to strip away the heat shrink cover over the pickup rod. There's a couple more SMD parts there at the preamp end, apparently a resistor and capacitor in parallel. The element itself looks like a "Flex-Print" type of Kapton based material. I could not scrape away any coverage to get probe contact to see if the element - what's left of it - is resistive.
Whatever it is, it must be one tough little strip of material. The instructions came in the box and the pickup routing is insane. The majority of the strip goes underneath the bridge in the saddle slot as usual. Then it takes a hard right angle turn, up the side of the bridge, which you're supposed to shave the end slightly to accommodate the element thickness. Then a second, nearly right angle turn to the battery / circuitry enclosure, which is stuck onto the saddle with double sided sticky mat.
No piezo pickup, constructed of six individual bars of piezo material held in conductive channel, could mechanically take such an arrangement. So what is it?
FWIW Shadow is still in business and will sell just a "NFX" bridge pickup element for about $45, shipped. That's entirely reasonable, but like many engineer / musicians (I'd bet), I want the "lecture on Heaven" before walking through that door. Like a clear description of the operating principle, i.e. how it's able to work with just a voltage and passive support circuitry. How it can withstand right angle bends without breaking immediately?
Additionally, I have a Kala guitar with a Shadow pickup system. I bought it at a yard sale with the saddle ripped off the top. I've reglued the saddle twice and had it explosively come off, for a total of 3 times its pickup element has got the tar beaten out of it. It still works, which is the only clue I have suggesting that it too is of the unknown "NFX" technology.
I found a patent from the same company about something else that has one interesting sentence in its description:
https://patents.google.com/patent/DE10309838A1/en
In the (translated) text, it says: "Use of piezo-ceramic sensors, piezo film sensors, Piezo polymer sensors or Back electret sensors for the piezo sensor according to one of claims 1 to 16."
Apparently piezoelectric film sensors and piezo polymer sensors exist. Could either of these be the flexible sensor type you are interested in?
https://patents.google.com/patent/DE10309838A1/en
In the (translated) text, it says: "Use of piezo-ceramic sensors, piezo film sensors, Piezo polymer sensors or Back electret sensors for the piezo sensor according to one of claims 1 to 16."
Apparently piezoelectric film sensors and piezo polymer sensors exist. Could either of these be the flexible sensor type you are interested in?
Thanks. I've been aware of that for a few...decades. Even had a sample kit back in the early 80s of a silver colored film - looked like an electrostatic bag - that was piezoelectric.
However, in this application, the battery / passive component combo I observed in the one Shadow design I purchased is illogical, as piezo material generates its own signal. I assume by moving charge across a high value resistance.
I'll guess it's a thin film resistor deposit on a flexible substrate, that they discovered changes value with mechanical load, perhaps similar to a carbon pile when squeezed. Wish they'd just 'effin say so, instead of another verbal improv on the same musician geared marketing BS everyone uses -
I'll guess the business is struggling, even though they have a superior product. The Kala sounded great, especially the low end, which seemed to go all the way down to subsonic, like a wiggled potentiometer would with a voltage across it. I'll guess that the piezo based equivalent, EQ'd and amplified to sound decent, is so ingrained in today's amplified acoustic guitar sound they just cant compete. Anyone's Taylor I've heard always seems to sound really good regardless of model; I assume it's piezo.
I can get a piezo based under bridge system for $15 from some China manufacturer - complete with amplified endpin jack, battery holder and everything, while Shadow wants $260 retail for their NanoFleX setup. Methinks they better reveal some detail on how it works, how it picks up vibration from the guitar body in addition to the strings, why a piezo cannot do that, if they want a customer to realize it's a very distinguished pickup system. But that's just me.
Continuing the guessing game; a guitar bridge shaped variation of this pressure sensor.
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