mattell starmaker guitar, with optical pickup system...

[Elektrojänis]

You might find the vibration from the speaker mounting on the top plate has more effect than the sound though the air.  Flipping the speaker polarity is certainly worth playing with.

I once attatched a small (3" maybe) speaker to the top of an old russian acoustic guitar. Made a hole for behind the bridge it and all. Then I made a diy pickup for it from old magnets, shett metal and copperwire out of old small electric motors. Stuck an amp circuit in there too. It was an LM386 thing with an electra distortion in front of it... Well... if I remember it correctly... It was over 20 years ago. Anyway... That thing sustained like crazy on some notes and some just died instantly. Never tried to switch the speaker polarity though...

Mounting the speaker straight to the instrument will make it feedback easier for sure.

[pinkjimiphoton]

its also important that the string is tight enough. if it's too slack, it won't sustain and feedback right.

[Rob Strand]

I once attatched a small (3" maybe) speaker to the top of an old russian acoustic guitar. Made a hole for behind the bridge it and all. Then I made a diy pickup for it from old magnets, shett metal and copperwire out of old small electric motors. Stuck an amp circuit in there too. It was an LM386 thing with an electra distortion in front of it... Well... if I remember it correctly... It was over 20 years ago.

I'm always impressed by some of the stuff people build from scratch, really cool.

Anyway... That thing sustained like crazy on some notes and some just died instantly. Never tried to switch the speaker polarity though...

Driving the top at a single point might do that.   Spreading the drive points will even things out a bit.  You just have to hope after doing that it still sustains.

[Rob Strand]

I once attatched a small (3" maybe) speaker to the top of an old russian acoustic guitar. Made a hole for behind the bridge it and all. Then I made a diy pickup for it from old magnets, shett metal and copperwire out of old small electric motors. Stuck an amp circuit in there too. It was an LM386 thing with an electra distortion in front of it... Well... if I remember it correctly... It was over 20 years ago.

I'm always impressed by some of the stuff people build from scratch, really cool.

Anyway... That thing sustained like crazy on some notes and some just died instantly. Never tried to switch the speaker polarity though...

Driving the top at a single point might do that.   Spreading the drive points will even things out a bit.  You just have to hope after doing that it still sustains.

its also important that the string is tight enough. if it's too slack, it won't sustain and feedback right.

That might have something to do with moving the string pitch up into the range where the speaker has a stronger output and top plate is starting to resonate.   

[pinkjimiphoton]

well, it needs a relatively phat string. the stock is an .054, i don't have anything near that heavy, there's an .042 on it right now which may be part of the problem i'm having with it.

my singer's kid had one 40 years ago and i loved it, it was awesome. his was bone stock, but i remember until you tightened up the string enough, it wasn't great but when you did,HOLY COW.

i would postulate also you need to get the string tuned to a resonant frequency for the guitar to track its best.
i'm just getting boards cut for the latest run.... vero baby...
but will try and get dimensions today or tomorrow. i just picked up a venerable roland g707 guitar and have been rather enamored more than working, and daddy needs to pay that suckah off so jobs gotta get did.

stay tuned       <<<baddad joke, i know

[duck_arse]

No Brians involved. Instead, pick the prettiest maiden in the village and make her dance around a maypole.

How do you play that thing (centre) sitting down?

That Fire Bird (right) is a stunner.

swung around the head is the only way I can see that mess of pointyness stunning anyone. actually, I'm just, y'no, bumping.

[pinkjimiphoton]

ugh life keeps happening. new puppy pulled old computer off table, thereby smashing the @#$% out of it so everything's weird, but i will be here today and try and get measurements for ya, bro.

stay tuned. just getting re-conscio for the day. mas tequila was poured down my throat last nite in between massive doobage and some very tasty fresh fungii at the gig last nite.

it was epic. but now i gotta get functional in multiple ways and levels.

stay tuned!

this pos pc literally took 15 minutes to get to the point i can type this to ya. ugggggh....

[duck_arse]

ugh life keeps happening.
.......
this pos pc literally took 15 minutes to get to the point i can type this to ya. ugggggh....

that's ok, I'll read it slowly.

[duck_arse]

some-ish progress. I have a plank of wood, and some other bits of wood, and some cuphook and screws, and some 60lb coated wire leader (for fishing) strung on as a twanger test bed. and I've hacked a Tx-Rx from a mouse, almost this exact mouse model (site is non-https, so I won't img it here).

http://www.tcocd.de/Pictures/Peripheral/Logitech/ms35-1-3_large.jpg

the sensor (the red package) and led (the black boxed, also three legs) I have is exactly as shown there, but I can't find data for the encoder IC, and can't tiny-brain fathom the polarity/sense of the Rx pair. it has three legs and I assumed common emitter npn. and it didn't work as I expected, wired as per Rob's early circuit. so I reconfigured, just to prove, and it does work, but I dunno which way is up from my results. it is less sensitive to room light, but will need to be insulated some.

any ideas on polarity, or encoder datasheets? motorola part, but Logitech house numbered, of course.

[pinkjimiphoton]

some-ish progress. I have a plank of wood, and some other bits of wood, and some cuphook and screws, and some 60lb coated wire leader (for fishing) strung on as a twanger test bed. and I've hacked a Tx-Rx from a mouse, almost this exact mouse model (site is non-https, so I won't img it here).

http://www.tcocd.de/Pictures/Peripheral/Logitech/ms35-1-3_large.jpg

the sensor (the red package) and led (the black boxed, also three legs) I have is exactly as shown there, but I can't find data for the encoder IC, and can't tiny-brain fathom the polarity/sense of the Rx pair. it has three legs and I assumed common emitter npn. and it didn't work as I expected, wired as per Rob's early circuit. so I reconfigured, just to prove, and it does work, but I dunno which way is up from my results. it is less sensitive to room light, but will need to be insulated some.

any ideas on polarity, or encoder datasheets? motorola part, but Logitech house numbered, of course.

dude that is wayyyyyyyyyyyyyyyyyyy far above my paygrade... BUTTTTTTTTT  << the big butt, that 'tis, rite their

u know i wuz thinkin about how much it must suck to be building a barn and waiting on pink jimi for measurements,
i know that phatass, and he's a real piece of work

https://jimipocius.com/pokyass.htm

so i dug thru my dungeon and whipped out my measuring extendable flex stick and applied it to the "instrument" in question.

i think the 'vid done made mine shorter. hope its not permanent.

but then i was like, oh yeah, forgot about duckster, and pulled the starmaker out its narrow house
and had me a measuring fest.

total length of this suckah is 25" empiricle. what ev that means, i saw it somewhere and it looked 'phisticated.

scale length is 18" 5/16ths from bridge to nut

hey beavis, he said nut huh hunh uh uh heh heh

two inches exact from point string exits body behind the bridge. string length from that hole is 21 total to nut

he said nut again

i didn't measure width of neck or anything.

i did notice that it plays and sustains best tuned up to around a g or a on the low e of a geeetar. ya get the right tension, and it feeds back on itself, nice and bloomy, you can play it on one hand.

right now i'm synthesize-in' all down the dungeon way, so its kinda hard to do anything else with that huge old gr700 there, but i gotta replace that pot i f'd up in it anyways, so i gotta take it apart. i will try and determine which part is what if at all possible while i'm in there, once i get a chance to get in there.

the fan base.... i love them, no idea why they gaf about anything i do... all wanna hear that bizzarre ass piece of iniquity so i gotta get at least a good bank or two of patches writ by thursday this week. which may take a while cuz i'm second guessing all the shit i lost when the mem cart went down last week. got some amusing filter swept rick wakeman stuff saved, but still chasing my sig bass sax sound i used to use i was so proud of. not a baritone sax, a BASS sax. it was sick!

anyways.. dimensional vengeances put aside, hopefully them numbers will help in the pinnochioic cobbling ahead in the house of duck arse. 

pink out!

[amptramp]

If you look at this video at 1:58, you can see the extent of string movement that may expose a drastic difference if you are playing hard enough between normal guitar pickups and an optical pickup:

https://www.youtube.com/watch?v=j_Z1273i5dM

If the strings move far enough, you may start with a centered pickup in the lit state, it moves into the dark state as the string crosses it, then the string goes beyond that state and goes light again, then returns to the dark state and then to the lit state as it crosses the zero deflection position then does the same thing in the opposite direction.  This means the neck pickup might multiply the string frequency by four whereas a bridge pickup may never get to the point where the string goes past the pickup.  So where a normal electric guitar has best response to the lowest notes at the neck and the bridge is optimized for treble, the optical guitar may do the same but you may get frequency quadrupling at the neck as it goes through two dark states on each side of center.  Of course, the acoustic guitar doesn't do any frequency multiplication.

This should be an interesting build if someone decides to do it.  I have never seen an electric guitar exhibit frequency quadrupling but as the video of the acoustic guitar shows, it would be very possible with an optical pickup, especially since the string doesn't have to drive an acoustic chamber or move past magnetic strings.  In the video, Sarah is not playing all that hard and the strings are encroaching on the rest positions of other strings, so you may get additional frequencies as the adjacent string crosses into the position of the optical pickup.

And if you get the impression that I love Sarah Smith, you are right - I have put her on the Sound of the Day thread twice now.

[duck_arse]

thank you pjp, I have written those numbers on their very own diagram, specially. your measure sez 465 ish mm, turns out my wood is 442 mm. close, already.

further calmer observations of my mouse sensor shows them to be dual diodes, common Kathode, and reverse biased in the mouse board. meter now tells me I have fritzed the first device, lucky I've got about 8 more mouses.

this leaves me asking for help - I've got no idea how to even use these diodes as sensors. but, having them dual, I have already thought of octave-down on one pickup, and mixing both sensor outputs at the 386 input, prior processing or not. anyone?

edit for today.

[duck_arse]

I hate to say it, but I think all three of those guitars should be burned.  Any "horns" on a guitar body should be the natural result of adding a functional cutaway to an otherwise classic body shape.  Instead, these are monstrous exaggerations.  The one in the middle looks like someone accidentally cut away too much and tried to make it look intentional.  The one on the left might look better without the weird pickguards, which just look like super lazy switch mounting.

And get off my lawn!

Eric, it is well known that what you lose on the wings, you make up on the rounder bouts. twang! ow-ow-ow-ow-ow.


must have been a solar storm, or an EMP or something. none of my dectectors now read on the meter diode test like they did yesterday, but they all work fine under IR. well, work when they aren't loaded with 10k resistors, pnp buffer transistor is swinging 5V7 volts led on to led off. progress.

[Elektrojänis]

I once attatched a small (3" maybe) speaker to the top of an old russian acoustic guitar. Made a hole for behind the bridge it and all. Then I made a diy pickup for it from old magnets, shett metal and copperwire out of old small electric motors. Stuck an amp circuit in there too. It was an LM386 thing with an electra distortion in front of it... Well... if I remember it correctly... It was over 20 years ago.

I'm always impressed by some of the stuff people build from scratch, really cool.

Some times it seems a bit odd to even me what I've managed to make work back then, like an actual condenser microphone... Not using a commercially built capsule or anythin. I built even the capsule myself from various pieces of junk. The diaphragm is made from kitchen grade aluminium foil. But then time went by and somehow I ended up wanting to make stuff too perfect in some ways. So instead of just hacking stuff together I mostly just plan stuff in my head without actually even starting to build anything because I've pushed the bar for myself too high. Then again, nowadays there is plenty of all kinds of impressive builds documented on the internet, including some stuff on this forum.

Anyway... That thing sustained like crazy on some notes and some just died instantly. Never tried to switch the speaker polarity though...

Driving the top at a single point might do that.   Spreading the drive points will even things out a bit.  You just have to hope after doing that it still sustains.

I remember there being far more notes that sustained than ones that died. I actually dug that guitar up when I visited the basement the other day. I thought I would try if it still works and maybe even record a little soundclip or video. Sadly, the pots and swiches I had mounted to the top were smashed. Fixing it is probably not worth it. The guitar itself is an absolute junk.

Looks like this: https://ibb.co/qmg1nP8

http://www.tcocd.de/Pictures/Peripheral/Logitech/ms35-1-3_large.jpg

the sensor (the red package) and led (the black boxed, also three legs) I have is exactly as shown there, but I can't find data for the encoder IC, and can't tiny-brain fathom the polarity/sense of the Rx pair.

Most mice I've taken apart have the led and the sensor in a same package that's kind of like a fork or something... Or at least those I can remember. That kind of a combo might be easier fort the positioning when you dont have to aim the led to the sensor.. On the other hand separate ones might allow more freedom for the distance between the two.

[duck_arse]

we have howl!

I now have jfet buffer/amps feeding the 386 - the test plank string is so high, it only plays one note, over and over and over ..... with the two outputs fed to level pots and summed at the (+) in, it's loud and hissy noisy, but works. messing about, I pulled the 10uF gain cap, the hissy left, still loud, less distorted.

then I lifted ground from the (-) in and fed one buffer to each input. LOUD and not hissy. then I put the gain cap back, and it WILL howllllllllllllll, just the log on the desktop with a computer speaker nearby.

the dual pickups can be adjusted in their mount, and do produce noticable differences on the cro, but my ears aren't attuned enough to these things to say there's any tonals to be had. detector has nothing more than a bit of card over the top as light shield, seems to work well even with the desklamp hovering. progress.

[pinkjimiphoton]

i will try to get the blown pot replaced and get you some video of the actual unit today, sounds like you got this, bro!

[Rob Strand]

So instead of just hacking stuff together I mostly just plan stuff in my head without actually even starting to build anything because I've pushed the bar for myself too high.

It can be a problem  .  I've written out 15 pages of thoughts on stuff I might have just bread-boarded when I was a kid - but it's not  the same level!

I remember there being far more notes that sustained than ones that died. I actually dug that guitar up when I visited the basement the other day. I thought I would try if it still works and maybe even record a little soundclip or video. Sadly, the pots and swiches I had mounted to the top were smashed. Fixing it is probably not worth it. The guitar itself is an absolute junk.

Looks like this: https://ibb.co/qmg1nP8

Still, it's cool idea and putting the guitar to good use - scientific purposes.

I like the sticker, Chilli's from Jatujak market 

[duck_arse]

my test plank (from an old lounge) has a bit of wood bridge, pushed back far enuff for string tension, and a bit of wood nut, stuck into a slot that happened to be there. as such, string height is 10mm. that's why it only plays one note, that and the fishing leader string.

I fitted a second pair of pickups, closer to the neck. twang twang wahhhh ahhhh eeeee etc. for some variation, I slipped a bit of wood (no no, a different bit of wood) under the string and added a screwdriver for a fret - and bloody hell. wang the string and it sounds like a japanese koto, might or might not howl, that can be tuned in and out with the pots/level mix.

but there's more. you get notes by bending and they go screaming or duller, now it sounds as playing a theremin. but like it's a slide guit. as for whether it could be called an instrument, I dunno.

the pickups from the mouse can be tuned, they have a very pronounced sweet spot, double null sort of thing, where the sound leaps at you. so pivoting mounts, selector switches, phase order, non/invert ...... it's getting more stuff by the day.

[pinkjimiphoton]

sounds from your description like you're getting it. the string has to be tite enough for it to work right, and pretty thick... gives a wider sweet spot... but the description of how it jumps out when ya get it just right sounds on point.
i had a rehearsal last nite with my side band, the tribal elders, two of whom were out due to the 'vid for almost 2 months, so no chance to get to video. maybe today.

i take forever, i know. but i gotta be able to get to my workbench and fix that volume pot first and i've just been too busy

[pinkjimiphoton]

i'm making a little more progress, got the broken pot replaced, added a speed knob cuz...well, everything should have speed knobs.. its mostly working. shot shitty video so ya can see how crummy it is without the battery secured in the back cuz i drank wayyyyyyyyyyyyyyyyyyyyy too much tequillie last nite and spaced it out. anyways, video, heavy on the dumb, of course....

https://www.youtube.com/watch?v=93P2VsuPQNY

also, extra added bonus, a couple of the more interesting pages in the owner's manual

won't let it upload for some reason... i'll try when i get back on my real 'puter next week sometime