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petit choux posted:Anything else you guys can think of? Just use a cheap projector and project an image of said fretboard as accurately as possible over the field, for example? The two-antenna design is more down to how the original theremin actually worked internally. You could probably get away with making a one-hand-only one using ultrasonic transducers, though that sounds like you'd be taking the already notoriously difficult to play theremin and making it downright impossible.
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Nov 3, 2021 17:15
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Shame Boy posted:The two-antenna design is more down to how the original theremin actually worked internally. You could probably get away with making a one-hand-only one using ultrasonic transducers, though that sounds like you'd be taking the already notoriously difficult to play theremin and making it downright impossible. Well this isn't just a Theremin, they've made a lot of progress over the years. This is actually a MIDI controller with a Theremin interface. And incidentally, my biggest soldering project yet. It only plays notes, and in designated key and scale. And both sensors can control notes, pitch bend, all sorts of stuff. Does not have to control notes, so you can use it to send any two MID CCs. But anyway, I just realized I've never seen anybody use a familiar Cartesian grid configuration for them and I'm wondering why. Of course no reason I can't.  ED: Okay. The guy from Zeppelin said they'd interfere with each other so I'll leave it at that. Other questions still apply. petit choux fucked around with this message at 18:18 on Nov 3, 2021 |
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Nov 3, 2021 17:27
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fwiw those ultrasonic sensors are a lovely way to do the kind of sensing you want for that, i would highly recommend trying out some time-of-flight sensors, specifically VL53L0X/VL531X, which use reflected IR light instead of ultrasonic rangefinding. theyre far more accurate + consistent and have a magnitude less signal noise than those cheap ultrasonics, it should also eliminate the crosstalk between sensors you get w the ultrasonics if used in multiples. they have a shorter effective range, iirc 0-2 meters for the cheaper of the two, but that should cover you for normal 'playing', i would think. i'd also observe, somewhat pedantically, that that is *not really* a theremin as i've heard them discussed, but rather a similar non-contact instrument that operates by a fundamentally-different mechanism; theremins are defined by operating using electric capacitive feedback between the user and the antennas, iirc pure ultrasonic/IR/laser etc rangefinding for two-sensor frequency/amplitude control only partially emulates the Thermin Sound, not considering some of the spookier capacitive effects, and has a fundamentally-different 'noise profile' that won't give the same sound, as i understand it. bearing in mind ive only hosed around with a similar rangefinding-style instrument a little myself
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Nov 3, 2021 19:45
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Ambrose Burnside posted:fwiw those ultrasonic sensors are a lovely way to do the kind of sensing you want for that, i would highly recommend trying out some time-of-flight sensors, specifically VL53L0X/VL531X, which use reflected IR light instead of ultrasonic rangefinding. theyre far more accurate + consistent and have a magnitude less signal noise than those cheap ultrasonics, it should also eliminate the crosstalk between sensors you get w the ultrasonics if used in multiples. they have a shorter effective range, iirc 0-2 meters for the cheaper of the two, but that should cover you for normal 'playing', i would think. quote:i'd also observe, somewhat pedantically, that that is *not really* a theremin as i've heard them discussed, but rather a similar non-contact instrument that operates by a fundamentally-different mechanism; theremins are defined by operating using electric capacitive feedback between the user and the antennas, iirc pure ultrasonic/IR/laser etc rangefinding for two-sensor frequency/amplitude control only partially emulates the Thermin Sound, not considering some of the spookier capacitive effects, and has a fundamentally-different 'noise profile' that won't give the same sound, as i understand it. bearing in mind ive only hosed around with a similar rangefinding-style instrument a little myself Please then, good sir, allow me to make a correction. I said above it's a MIDI controller with a Theremin interface. If I may I'd like to change that to a "Theremin-like interface," for the benefit of purists and curmudgeons everywhere. It also has a killer arpeggiator.
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Nov 3, 2021 22:39
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petit choux posted:I don't suppose that's something I can just drop in there instead. it's essentially interchangeable w the ultrasonic sensors if you're driving this w an arduino or something similarly-agnostic, i don't think it'd be an issue unless you're rolling your own controller from discretes or something. hotswapping the two is a really common upgrade for anything doing short-range rangefinding, i did it a couple of times on robotics projects a couple of years back petit choux posted:Please then, good sir, allow me to make a correction. I said above it's a MIDI controller with a Theremin interface. If I may I'd like to change that to a "Theremin-like interface," for the benefit of purists and curmudgeons everywhere. It also has a killer arpeggiator. i know, i know. but as i was Theremin Gatekeeped in my day, so shall i Theremin Gatekeep going forward. if only to warn about how Theremin Heads are perpetually-weinerey about this sort of thing, now and forevermore
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Nov 3, 2021 23:09
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Ambrose Burnside posted:i know, i know. but as i was Theremin Gatekeeped in my day, so shall i Theremin Gatekeep going forward. if only to warn about how Theremin Heads are perpetually-weinerey about this sort of thing, now and forevermore Being that the Theremin is at the intersection of obscure music, radios, and Star Trek... My god... I can only imagine
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Nov 3, 2021 23:50
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i say this with love, even though it is incredibly damning: it is one of the instruments Weird Instrument Guys retreat to when they need a new fix of Im Into Some Pretty Obscure Things You Probably Havent Heard Of
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Nov 3, 2021 23:57
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Ambrose Burnside posted:i say this with love, even though it is incredibly damning: it is one of the instruments Weird Instrument Guys retreat to when they need a new fix of Im Into Some Pretty Obscure Things You Probably Havent Heard Of It's really well known I just thought it was notoriously difficult to pick up. Moog hands them out like candy.
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Nov 4, 2021 00:01
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true, yeah, "most people will never even be capable of theremin proficiency" is the actual Exclusive Factor there
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Nov 4, 2021 00:07
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Which is what's great about this Altura. It is a MIDI controller with a Theremin-like interface.
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Nov 4, 2021 00:18
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Ambrose Burnside posted:it's essentially interchangeable w the ultrasonic sensors if you're driving this w an arduino or something similarly-agnostic, i don't think it'd be an issue unless you're rolling your own controller from discretes or something. hotswapping the two is a really common upgrade for anything doing short-range rangefinding, i did it a couple of times on robotics projects a couple of years back Wow, sweet. I think I'll run that by the guys at Zeppelin. It would really make my day if it's that easy. Oh, this does appear to be an Arduino device? You wanna take a look at the schematics? But no seriously, this Altura you can tell it what key to play in, what root note, and what scale with like 8 different ones to choose from, then your palette of notes begins from there, and you control which note with your right and your pitch bend with your left, or that's the configuration out of the box. And then you can turn on the arpeggiator. It's just a combination of a handful of the funnest things about electronic music in a cheap, DIY package. So unlike the original Theremin, you can only play discordant sound if you try. petit choux fucked around with this message at 00:30 on Nov 4, 2021 |
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Nov 4, 2021 00:23
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Ambrose Burnside posted:re: wanting a slow + consistent motor, a stepper is workable (especially if this is only going to be infrequently activated for display) but not ideal, it'll run hot as poo poo and generally waste a lot of energy holding things stepwise despite the lack of any loading requiring that energy expenditure. given your need for ~33RPM, look into synchronous motors, they're cheap, come in fairly small sizes, run off AC mains voltage, and are inherently suited to running accurately at a low RPM in the exact range you need. you won't even need a driver or any other parts, the platter can be directly driven from the motor shaft, if you don't care about vibrations like you do in a real working player anyways. they're motors that are inherently synchronous with the AC supply frequency of 50/60hz, which serves as an extremely accurate clock signal;they're what are normally used for real record players, iirc, alongside other applications like clocks, microwave turntables, sometimes washer+dryer timers, etc. just browse a couple distributors' catalogs and/or aliexpress to get the lay of the land and pick the smallest you can find that meets your voltage and RPM requirements That sounds good, but I'll be running this off either batteries (18650 because I have a hundred of them) or a 5-9V power supply as the only other electronics in this diorama will be some LEDs. The accuracy isn't very critical. It is just a scale replica of a record player so if runs at 30-35 or even 25-40rpm, I don't think anybody would notice.
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Nov 4, 2021 00:25
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If it doesn't need to have high accuracy then maybe a geared DC motor would be good but I don't know enough to offer specific recommendations.
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Nov 4, 2021 00:29
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Here, 
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Nov 4, 2021 00:31
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petit choux posted:Hi guys and dolls, here's a question for you. This Theremin uses ultrasonic sensors to detect the proximity of my hand. So the area my hand can move in to make sound is a field but it's mostly linear, with the pitch basically basing itself on the distance from my hand to the sensor. If I wanted to give myself some clear visual guide for where to identify the next notes, I was thinking I could put a row of lasers underneath this field pointing up, indicating where the notes are basically, like maybe an octave of them. Is this at all practicable, or should I just stick a ruler under neath the field and call it a day? Considering price, energy consumption, etc. is it doable? Lasers get too hot? Anything? Is there a better alternative? Anything else that maybe puts out light in some kind of usable way for this idea? Doesn't really have to be lasers. If moving your hand toward/away from the antenna changes the output frequency, couldn't you use the output frequency itself to drive the optical indicator? Buffer off a copy of the output signal, maybe run it through an automatic gain control unit to get a more predictable output. Then there would be a couple of options depending on what you want to do: 1) run the frequency signal through a frequency-to-voltage converter so higher frequencies become higher voltages. Run that through a bar graph, or through an analog voltmeter with 'notes' marked off on the scale, light up LEDs when the voltage is in a given range via comparators, etc. 2) Painstakingly make a bunch of bandpass notch filters for all the notes you care about, drive whatever output light you want based on the amplitude of the signal that gets through each one. (aka a 440Hz 'concert A' notch filter would pass only 440Hz, rectify that and drive an LED current proportional to the amplitude, or just turn on the LED when the rectified signal passes some threshold level). 3) Get one of those cheap guitar tuners that show all of the notes and how many cents you are off of the closest one, run your signal into it. (Or bust out the LEDs on the display and use those signals to drive whatever you want to be your indicator. This is just using the guitar tuner to do your DSP over multiple octaves.)
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Nov 4, 2021 00:31
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BattleMaster posted:If it doesn't need to have high accuracy then maybe a geared DC motor would be good but I don't know enough to offer specific recommendations. The hobby ones can be pretty loud, I wonder if there's room in the base of the diorama for a motor with a belt reduction and a shaft up into the record player model
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Nov 4, 2021 00:33
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PDP-1 posted:If moving your hand toward/away from the antenna changes the output frequency, couldn't you use the output frequency itself to drive the optical indicator? I appreciate this and I hear you but I think I really am looking for something a little bit more chartlike, because the chief difficulty for learning Theremin players is accurately judging in advance where to place their hands. Hope I'm clear. The laser idea was just a thing that popped into my head as I was typing. I'm kinda thinking I can just as easily suspend some kind of armature out over the fields of "vision" that the sensors have, maybe even ultralight or collapsible, which has say, threads hanging down just to tell me where those notes are. I mean lasers would be cool looking but no need to overlook simpler solutions. Also, what poster above said using LEDs instead of lasers is more practical than lasers and if I use enough of them it will have a similar effect to what you're saying. The hand will begin to reflect the color of the nearest light, which will be tied to a note of course. Would be a lot more energy efficient than lasers too I'm sure. petit choux fucked around with this message at 01:12 on Nov 4, 2021 |
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Nov 4, 2021 00:42
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While I was kinda mulling the idea of lasers I found this on ebay: DIY Kit C51 MCU Laser Harp Kit String Electronic Keyboard Kit Parts for Study https://www.ebay.com/itm/283910320356?hash=item421a5fb0e4:g:McQAAOSwUPVcIKYz  ED: There needs to be some kind of unofficial recognition for all those inventors in Hong Kong or wherever that knock stuff like this together.
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Nov 4, 2021 00:50
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I'm seeing the price on these time-of-flight sensors is pretty low, I'm going to look into this.
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Nov 4, 2021 02:09
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petit choux posted:While I was kinda mulling the idea of lasers I found this on ebay: Twelve bucks plus shipping, wild I remember when laser pointers were a hundred bucks each and a real flex to own/use one in the 90s. This has 7 lasers Bought one at the $12 price point, what a crazy invention, thanks for linking. hard to imagine someone went through the trouble of designing and manufacturing such a low volume board, good call out on the people doing this
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Nov 4, 2021 13:08
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if you're going with a non-capacitive ~pseudotheremin~ i think it opens some doors wrt the 'locating features' you can make use of for finger placement feedback. with a 'real' theremin you couldn't interact with any physical part of the unit without it short-circuiting the air capacitance that makes the music go, but that's a non-issue here. i think i'd shoot for the barest minimum of a physical indicator you can make practical use of, just so there's some real Tactile Feedback available. you could probably make it work with a set of long whippy wires or filaments approximately enclosing the 'play area'; ironically you could also *start* making use of capacitance sensing with physical 'strings', but not for making sound as is typical; set it up so the entire antenna is a capacitive plate and have it light up a LED on the tip when sufficient proximity or contact is made, that kind of thing
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Nov 4, 2021 18:14
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Hadlock posted:Twelve bucks plus shipping, wild Yeah, there seems to be a hard corps of inventor types just putting stuff like that out there. On ebay, you find stuff like this now and then, I'm sure you do a number of other places. Since I started watching those videos about making a little tack welder out of transformers, I've encountered a number of people selling me stuff to do that. But I've also now become aware that there's one for sale, a little less DIY, at Harbor Freight as well. So there are a bunch of creative minds out there.
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Nov 4, 2021 18:28
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Ambrose Burnside posted:if you're going with a non-capacitive ~pseudotheremin~ i think it opens some doors wrt the 'locating features' you can make use of for finger placement feedback. with a 'real' theremin you couldn't interact with any physical part of the unit without it short-circuiting the air capacitance that makes the music go, but that's a non-issue here. i think i'd shoot for the barest minimum of a physical indicator you can make practical use of, just so there's some real Tactile Feedback available. you could probably make it work with a set of long whippy wires or filaments approximately enclosing the 'play area'; ironically you could also *start* making use of capacitance sensing with physical 'strings', but not for making sound as is typical; set it up so the entire antenna is a capacitive plate and have it light up a LED on the tip when sufficient proximity or contact is made, that kind of thing I just got word from the creator of the device that those optical sensors are not just a drop-in replacement unfortunately. He also tells me that light pollution is still an issue for these things, hence his choice of ultrasonics. I don't know if or when I'm going to incorporate some kind of visual guide, a fretboard, so to speak, or whatever but I probably will, and you can put objects in the field wherever you need a note -- a capo, so to speak -- and all kinds of fun and games with that. Right now I'm envisioning an old-school television antenna, the kind with two telescoping parts, but disconnected from anything and attached a few inches above the top of the Altura. You then extend the telescopes, settle them directly above the field of the sensors, and then put little lights or markers indicating the notes, or more or less where your frets are. You can then also hang down little panels to act as capos. That's one thing I'm imagining.
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Nov 4, 2021 18:48
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You could probably rig up a pretty simple belt-drive vertical axis with a flapper on it that can rotate in and out of the detection area, one of those for each ultrasonic sensor and you can automate it really precisely.
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Nov 4, 2021 19:37
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poll plane variant posted:You could probably rig up a pretty simple belt-drive vertical axis with a flapper on it that can rotate in and out of the detection area, one of those for each ultrasonic sensor and you can automate it really precisely. Oh hey plane. Yeah, there's a number of ways to explore. One simple thing I learned already is that with both hands, you can do a lot more, and since the left sensor is just pitch bend, you can put both hands to the other sensor and do stuff with two hands you couldn't do with a regular Theremin. And the fact that it's operating on sound waves (or light) bouncing off things instead of capacitance it means you can use some kind of a "flapper" or "capo," which unlike capacitance don't care about your body mass. Like I had my coffee cup in range of the sensor a couple of times and I realized, I could just move things around on a table in front of this guy and generate some pleasant stuff. Come to think of it, it may be that some kind of "flapper" may work better with these sensors than your hand or whatever. Plenty of things to consider.
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Nov 4, 2021 20:10
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not sure where else to ask this, my appliances came with LEDs that have that horrible blue light thing where they are like 7000K. I have light photosensitivity so it's not good for me. they said they could send a technician to reduce the color temperature (at the very least get rid of the blue tint). How does this work exactly? they are those strip LEDs, or whatever they are called. there are five separate little LEDs on one strip.
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Nov 4, 2021 20:27
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poll plane variant posted:You could probably rig up a pretty simple belt-drive vertical axis with a flapper on it that can rotate in and out of the detection area, one of those for each ultrasonic sensor and you can automate it really precisely. Or maybe I can just put a bike wheel in front of it and put cards in the spokes like when we were kids wherever I want notes and spin the wheel in front of the machine. Gonna have to try that one now, jeez.
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Nov 4, 2021 20:28
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actionjackson posted:not sure where else to ask this, my appliances came with LEDs that have that horrible blue light thing where they are like 7000K. I have light photosensitivity so it's not good for me. they said they could send a technician to reduce the color temperature (at the very least get rid of the blue tint). How does this work exactly? they are those strip LEDs, or whatever they are called. there are five separate little LEDs on one strip. If it's just the little indicator lights on an appliance, they'll probably just put some semi-transparent tape over it to tone it down a bit. I know a lot of companies love putting SUPER BRIGHT white/blue-white LED's in everything these days and it's really fuckin' annoying. Not sure what you mean by "strip LED's" though, maybe post a picture?
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Nov 4, 2021 20:30
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Shame Boy posted:If it's just the little indicator lights on an appliance, they'll probably just put some semi-transparent tape over it to tone it down a bit. I know a lot of companies love putting SUPER BRIGHT white/blue-white LED's in everything these days and it's really fuckin' annoying. I fuckin hate it too. I have a bin of like 10 different sizes of through-hole and SMD red LEDs specifically so that I can replace the awful blue and white ones on products I buy.
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Nov 4, 2021 20:34
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I just gaffer tape over them. Also, I go in and desolder the speakers in stuff like standing fans because I don't need loudass beeps in my life.
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Nov 4, 2021 20:34
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actionjackson posted:not sure where else to ask this, my appliances came with LEDs that have that horrible blue light thing where they are like 7000K. I have light photosensitivity so it's not good for me. they said they could send a technician to reduce the color temperature (at the very least get rid of the blue tint). How does this work exactly? they are those strip LEDs, or whatever they are called. there are five separate little LEDs on one strip. A common complaint. They put LEDs that are way too bright in all kinds of stuff. And blue light messes with your sleep patterns, too. In the music forum there's occasional complaints about the LEDs on our equipment generating RFID and stuff too, though that's another story. Designers are just gaga for LEDs, just because they're so cool. And cheap. You can't even put a red gel over them, the light is so pure the red doesn't adequately affect the blue light. Here's your universal solution. 
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Nov 4, 2021 20:35
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VelociBacon posted:I just gaffer tape over them. Also, I go in and desolder the speakers in stuff like standing fans because I don't need loudass beeps in my life. Spoken like a true electronics head way out of my league. If I ever went so far as to do anything about that I'd snip that poo poo but my goon here desolders them.
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Nov 4, 2021 20:39
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Shame Boy posted:If it's just the little indicator lights on an appliance, they'll probably just put some semi-transparent tape over it to tone it down a bit. I know a lot of companies love putting SUPER BRIGHT white/blue-white LED's in everything these days and it's really fuckin' annoying. hi, sorry this picture prob sucks, first is the stock image of what it looks like, second is when I took it out, this is the back of course. there are five diodes on the other size that are maybe 1/4" in diameter each. I took most of my ceiling lights down and only use dimmable floor lamps because my pupils are really large - your pupils apparently get smaller as you age, but at my age (39) they are supposed to be around 5mm, and mine are 8mm. I have the pupils of a small child lol this causes problems because my eyes just take in more light than they should, and white and blue LEDs are the worst for this  
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Nov 4, 2021 20:46
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actionjackson posted:not sure where else to ask this, my appliances came with LEDs that have that horrible blue light thing where they are like 7000K. I have light photosensitivity so it's not good for me. they said they could send a technician to reduce the color temperature (at the very least get rid of the blue tint). How does this work exactly? they are those strip LEDs, or whatever they are called. there are five separate little LEDs on one strip. IDK if this is how your appliances work but I recently installed a selectable-color-temperature light fixture in a closet in my house with a little screwdriver-adjustable selector switch on the top (above the ceiling) side. Internally there are 2 colors temperatures of LED and the position of the knob just selects the brightness ratio between these two sets.
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Nov 4, 2021 21:05
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I tried putting some black duct tape over it just for fun, but it doesn't affect the color temperature, just the brightness. I think I would need something with a bit of a yellow tint. The light is prob more like 9000K or 10000K, and something like 4000K or 5000K would be best for me.
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Nov 4, 2021 21:10
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Ah yeah so like interior lighting LED's, gotcha. They definitely make tinted tape specifically for that purpose, I'm guessing that's what the technician will wind up using but if you ever need to do it yourself you can use some of this headlight tint film you can get cheap off amazon: https://www.amazon.com/1797-Headlight-Taillight-Chameleon-Accessories/dp/B07M8GT1SH/ Comes in a bunch of different styles and colors too so you can prolly find one that doesn't bother your eyes.
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Nov 4, 2021 21:14
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Kapton tape is a nice orangeish colour that would filter out the blues. Red acetate is also good for that, and should be available at Staples or wherever
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Nov 4, 2021 21:19
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ante posted:Kapton tape is a nice orangeish colour that would filter out the blues. Red acetate is also good for that, and should be available at Staples or wherever oh that looks good, thanks. would I just get the "regular model?" I'm kind of curious if there's a way to actually figure out what to use to go from color temp X to Y. I don't want to overcorrect and have it look like piss (literally) https://www.kaptontape.com/1_Mil_Kapton_Tapes.php
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Nov 4, 2021 21:32
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Ambrose Burnside posted:if you're going with a non-capacitive ~pseudotheremin~ i think it opens some doors wrt the 'locating features' you can make use of for finger placement feedback. with a 'real' theremin you couldn't interact with any physical part of the unit without it short-circuiting the air capacitance that makes the music go, but that's a non-issue here. i think i'd shoot for the barest minimum of a physical indicator you can make practical use of, just so there's some real Tactile Feedback available. you could probably make it work with a set of long whippy wires or filaments approximately enclosing the 'play area' quote:; ironically you could also *start* making use of capacitance sensing with physical 'strings', but not for making sound as is typical; set it up so the entire antenna is a capacitive plate and have it light up a LED on the tip when sufficient proximity or contact is made, that kind of thing BTW, as for lights I think having some fairly bright LEDs would work in the place of lasers and their diffuse light will maybe be good enough to indicate when you are getting near the next note. I'm not sold on the use of lights in any fashion particularly, just having clear markers underneath or hanging down from above indicating where the octaves are, maybe 3rds, 5ths, maybe all notes, I dunno, that may be all I need. I've never seen that in any pics of Thereminae. Having a telescoping tube extended directly below or above the sensors' fields and clipping lights onto them, that may be all I need.
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Nov 4, 2021 21:59
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ante posted:Kapton tape is a nice orangeish colour that would filter out the blues. Red acetate is also good for that, and should be available at Staples or wherever Like I said, it doesn't work, the red stuff. I've tried it with blue LEDs before.
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Nov 4, 2021 22:00
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