Sinecure posted:

You can definitely turn that accelerometer into a eurorack controller, keeping in mind a few things. It's powered at 1.8 - 3.6V at most, so you'll probably need a regulator since that's not standard euro power. The output is a ratio of its supply: 0V for -3g, supply voltage for +3g, and exactly in between for 0g. That is essentially CV at maybe a slightly lower amplitude than usual, so you could either add some dedicated scaling to the output or use another module for this (anything that can scale/offset CV will help you) - or use it as is, you can get at least a few octaves out of it. Finally, the ~32K output impedance isn't exactly eurorack standard but I doubt this is supposed to be a precision controller anyway. A little buffer/scaling circuit on the outputs can fix this but absolutely no need. Seems like you can short-circuit the outputs indefinitely so apart from powering it with the wrong voltage there's not much you can do wrong.

Oh, and it's a teeny no-leads package so will be a bit of a challenge to solder.

quote:

WE has some special features compared to other Midi control electronics (eg Pocket Electronic ):
The upper voltage that is assigned to the Midi data value 127 can be adjusted exactly with a multi-gang trimming potentiometer. This measure is necessary eg for modulation or pitch wheels, foot controllers or joy sticks that do not cover the complete angle of rotation. If such an element is connected to GND and + 5V the maximum output voltage is much less than + 5V (eg + 3V only). Even breath controllers (eg Yamaha BC-1/2/3) output only about + 3.5V maximum control voltage. If an electronics is used that analyzes the full voltage range 0 ... + 5V the higher Midi data values ​​are missing.
The voltage range can be reduced with the trimming potentiometer to 0 ... + 3V.
For each of the four elements a jumper is used to select if the full voltage range (0 ... + 5V) or the adjustable voltage range is used for measurement. This is necessary if different elements are used simultaneously (eg modulation wheels or foot controller with reduced voltage range and normal rotary or slider potentiometers with full voltage range).
If an element is assigned to midi pitch bend a "plateau" is used in the middle of the voltage / data range (data value 64). This feature is meaningful in combination with spring-loaded wheels or joy sticks as due to mechanical tolerances the exact center position is not always reached.

petit choux posted:

I think I follow you except what you mean by dedicated scaling. Also, where one might find some guidance on how to scale/offset, as you put it. So I can't just amplify that 3 volts to 5 or whatever w an op amp? Or would that be one way of doing that?

That, and you mention I should be able to get a few octaves out of it as-is. Not sure if it's relevant to what you're saying but I thought I was dealing with CC, not MIDI notes. Does that affect it?

Sinecure posted:

Yeah, exactly, you could either design something that you put in front of the accelerometer's output all the time, or plug it into something that can do it for you. I'm not that familiar with the Doepfer line but it looks like the A-183 can provide offsets, and pretty much any mixer or VCA with gain can increase the amplitude. To be clear, the output of the accelerometer is quite useful as it is but there's two things that could make it more useful IMO (fake edit: but I realize now that you don't necessarily want this to behave as a eurorack module):

1) it only goes up to the accelerometer Vcc, which is ~3.3V - most euro modules expect at least 0 - 5V, be it for pitch or other controls.
2) it is centered around half that Vcc, so no movement will already give some voltage and not 0V. Depending on what you want to use it for this could be a feature or a nuisance.

A simple output scaler could be something like this:



That'll turn your 0V / 0.5*Vcc / Vcc for -3g / 0g / +3g into -Vcc / 0V / +Vcc instead, doubling the range and setting the 'idle point' to zero. I'm not great at non-inverting op-amps but with some small tweaks I think you can get even more gain:



This will do -2*Vcc / 0V / +2*Vcc, or roughly -6 to +6V: more than enough for any CV control.

Obviously, the sky is the limit here, you could also put a full-wave rectifier on there:



This will make it so that both acceleration and deceleration produce positive voltages. You could then also put a comparator on it so that you have a gate output when 'moving', etc.. but you'll have gone from a tiny board as big as a postage stamp to something the size of a full module. And that's kind of the point with modular: there are lots of modules that can scale, offset, rectify so there isn't always a need to put it in every module, but that obviously depends on what else you have available.

Now, that was a lot of words before I actually realized what you wanted to do: it seems like this Wheel controller has specific trimmers to make it work with 0 - 3V input, so if you're fine with just the second caveat (no movement = half of Vcc, which seems fine for pitch control) there's no issue to plug it in directly.

Sinecure posted:

Yeah, exactly, you could either design something that you put in front of the accelerometer's output all the time, or plug it into something that can do it for you. I'm not that familiar with the Doepfer line but it looks like the A-183 can provide offsets, and pretty much any mixer or VCA with gain can increase the amplitude. To be clear, the output of the accelerometer is quite useful as it is but there's two things that could make it more useful IMO (fake edit: but I realize now that you don't necessarily want this to behave as a eurorack module):

1) it only goes up to the accelerometer Vcc, which is ~3.3V - most euro modules expect at least 0 - 5V, be it for pitch or other controls.
2) it is centered around half that Vcc, so no movement will already give some voltage and not 0V. Depending on what you want to use it for this could be a feature or a nuisance.

A simple output scaler could be something like this:



That'll turn your 0V / 0.5*Vcc / Vcc for -3g / 0g / +3g into -Vcc / 0V / +Vcc instead, doubling the range and setting the 'idle point' to zero. I'm not great at non-inverting op-amps but with some small tweaks I think you can get even more gain:



This will do -2*Vcc / 0V / +2*Vcc, or roughly -6 to +6V: more than enough for any CV control.

Obviously, the sky is the limit here, you could also put a full-wave rectifier on there:



This will make it so that both acceleration and deceleration produce positive voltages. You could then also put a comparator on it so that you have a gate output when 'moving', etc.. but you'll have gone from a tiny board as big as a postage stamp to something the size of a full module. And that's kind of the point with modular: there are lots of modules that can scale, offset, rectify so there isn't always a need to put it in every module, but that obviously depends on what else you have available.

Now, that was a lot of words before I actually realized what you wanted to do: it seems like this Wheel controller has specific trimmers to make it work with 0 - 3V input, so if you're fine with just the second caveat (no movement = half of Vcc, which seems fine for pitch control) there's no issue to plug it in directly.

petit choux posted:

I'm still in awe of this response. So BTW, if I were to include a full wave rectifier, I could make it something I could switch on or off manually in order to make all the numbers positive just for kicks, right? I can do a lot of simple things to change or enhance the output of the accelerometers, right? Like really cool things, really easily, with a few simple components that will work some basic math on the signal at that location?

ED: Or rather, there would be a lot of ways of performing simple logical operations on the CV and I'm guessing that's a good place to do it. Trying to think of what good simple operations ought to be here that I could do.

Dang It Bhabhi! posted:

Boards are here. I’m waiting on some parts in order to build and verify the circuit and in the meantime I’m setting up my website for easy ordering.

I figure $5/ea, which includes shipping, is reasonable? This should help to offset the cost to send to our international friends, not that it would be a problem anyhow. We’ll make it work!

Dang It Bhabhi! posted:

Marsupial Ape posted:

I am getting into DIY electronics projects and am toying around with cheap microphones. I’ve currently got some Chinese knock off SM57 transformers on order that I am going to install in some Pyle SM57 clones, as well do the 680ohm resistor mod on them. Just see how shiny I can polish these turds.

Does any body know any collections of DIY microphone projects suitable for a beginner? I want to get some practice in before I tackle this project: https://hackaday.com/2020/11/02/building-a-top-notch-electret-microphone/

Marsupial Ape posted:

That looks fun. I have a podcasting background, rather than music. That's why I am interested in microphones and the tonal qualities I can get out of them. But, yeah, if any of you know how to make your own XLR patch cables, jump a 680 resistor across the 2 and 3 posts on the male end and see what it does to the tonality of your dynamic mics.

petit choux posted:

Is this the basic design for an unbalanced-to-balanced adapter?

Dang It Bhabhi! posted:

Boards are here. I’m waiting on some parts in order to build and verify the circuit and in the meantime I’m setting up my website for easy ordering.

I figure $5/ea, which includes shipping, is reasonable? This should help to offset the cost to send to our international friends, not that it would be a problem anyhow. We’ll make it work!

Marsupial Ape posted:

That looks fun. I have a podcasting background, rather than music. That's why I am interested in microphones and the tonal qualities I can get out of them. But, yeah, if any of you know how to make your own XLR patch cables, jump a 680 resistor across the 2 and 3 posts on the male end and see what it does to the tonality of your dynamic mics.

petit choux posted:

Well congrats to you for not just using a sub bass synth for your voice like so many jerkoffs do. That is one of the things I've always hated about anything resembling a shock jock, morning zoo character, Howard Stern, most right wing radio hosts. They have no interest in subtlety ...

snorch posted:

I always thought that boomy wingnut/sportscaster voice was the result of the heavy compression they applied for better AM broadcast.

petit choux posted:

Well congrats to you for not just using a sub bass synth for your voice like so many jerkoffs do. That is one of the things I've always hated about anything resembling a shock jock, morning zoo character, Howard Stern, most right wing radio hosts. They have no interest in subtlety ...

petit choux posted:

Well I have finally found it. I can retrofit any cheesy audio toy with one of these.

Marsupial Ape posted:

I'm just full of questions, today.

I'm currently wanting to dick around with modding cheap microphones, but I've still very ground floor on this, knowledge wise. This guy goes into a lot of depth for building a high pass filter circuit, but a lot of it is way over my head. Can anybody with more experience translate? I swear I'm making my way through the Make: Electronics workbook, so I'll eventually get there.

petit choux posted:

Wow, cool. In other news I'm gonna try a couple of those adafruit cards.

Marsupial Ape posted:

Can't tell if snark or not.

petit choux posted:

Do what now? No, I just don't want to dive into your thing right now. I pulled the trigger on two of those cards is all. I'm hoping to learn a lot from your projects too. I'm just bumping the thread.

Marsupial Ape posted:

Ok, that’s cool. The internet has primed me for hostility, today. That’s on me. One of the later chapters in my workbook deal with Arduino boards and I’m looking forward to it.

petit choux posted:

And I'm eager to take notes on everything you're learning here with the mics, as well. This is great stuff.

Sorry I'm so excitable. I have some DIY projects that I've been playing around with for months/years and can barely contain myself I'm so excited. I'm going to be going into a handful of projects over the next few weeks, and I'm terribly excited to have fellow goons to talk with about it. I'm eager to hear about anything you can put out there too. As regards mics, I want to make something that you aim at a flat surface, such as in the above abandoned project, and make use of the principles that Crown capitalize on with their PZM mics. I have a bunch of Crown mics but I bet you can design something better than what I've got, electronics-wise that is. I essentially want to be able to just aim the capsule at the reflective surface at very close range. And if you can show me a really quality, easy mic project I can do this with I've got some spare capsules somewhere too.

Marsupial Ape posted:

I am not experienced in the least bit. I just have big ideas and my skills have to catch up. I am seriously just alligator clipping batteries, resistors, and LEDs together, right now. I mostly want to be able to make the best possible Chinese knockoff SM57 at the 35 dollars or less. I also want to see of I can fabricate my own polished turd of an SM7B knock off. This is mostly to satisfy my own degenerate desires, give as gifts...and maybe sell on Ebay (while making it clear they are not actual Shure products, of course).

I did do a little google fu, and here's a DIY PZM project video that might be right up your alley. https://www.youtube.com/watch?v=gdWHMuLmEDE

petit choux posted:

That's real cool. Yeah, I used to have some of Wahrenbrock's original PZM mics. I think I've seen Crown make somebody stop making knockoffs once. I don't want a knockoff, I just want to use reflective sound like they do and to differentiate myself I'd make it so you can use a separate surface from the mic instead of a one-piece solution, which should allow you to use tabletops or anything smooth and flat. Crown doesn't own the fact that reflective sounds cancel each other out, leaving a very pure, but weak sound. Stories of wily recording engineers using reflective sound in some project are apocryphal and outdate Wahrenbrock's patents. My band instructor taught me about stuff like that when I was a boy.