I've been really hyped up about direct digital frequency synthesis for... A few months? A year? And finally decided it'd be a fun project to simulate a DDFS in Python.
The fastest route to the source code/ipython notebook is here:
https://github.com/Cushychicken/dds-engine/tree/main/tools
With a full writeup available on my blog here:
https://cushychicken.github.io/direct-digital-synthesis-python-model/
My input and output must be PWM signal. I'll appreciate if you can link a research paper or any online article.
I'm thinking of taking better care of my ears and protect them from high frequencies. I usually work with professional headphones but I wonder if I should be going further with my ear care.
What you guys into analog synthesis do?
The challenge: write a combinator circuit that delivers 1-pulses of a given signal (say letter 'A') at a rate inversely proportionate to some input signal.
Say the input signal is copper cable, then the output period is linearly proportionate:
At 300 copper cable => pulse 'A=1' 1/30 ticks or 1Hz
At 600 copper cable => pulse 'A=1' 1/60 ticks or 500mHz
At 150 copper cable => pulse 'A=1' 1/15 ticks or 2Hz
... and so forth.
This challenge isn't purely a puzzle -- it has real uses in factory circuitry. For example, one could use it to signal "proportionate" activity by trains and/or logistic robots.
Sometimes I have a cool patch going where I have two oscillators beating against each other just the right way to sound good when I hold down a specific key, but then as I move up or down the keyboard the beat frequency changes. This makes sense, since usually you'd want to detune the oscillators for a specific interval which means the beat frequency will double in each octave. But sometimes (especially with low amounts of detune) I'd love to have the beat frequency stay the same instead. Which synths do you know that can do this? Apparently the keyword here is linear detuning.
The only ones I know off the top of my head are the Sub Phatty and Sub 37 from Moog.
I was just wondering this. I feel like I could spend hours drawing periodic functions and hearing what they would sound like.
A while ago I designed a direct digital synthesis VFO for the MHRS guys to use in their old transmitters. I also made sure it was configurable enough to be used basically anywhere, and high enough performance that nobody could ever complain about it. My beef with the (dozens of) existing DDS projects out there in the amateur radio community was:
- No ability to phase lock to an external reference
- First-gen DDS with subpar phase noise and spur performance
- Poor-quality reference oscillators with lousy stability
- Little attention to bypassing or power supply cleanliness
- Nonintuitive user interface
- No USB interface for PC control
In short, there's too much hobby crap out there, and I do this for a living anyway, so I rolled my own and had boards made by OSH Park (shout out to these guys, they rule).
People keep telling me I should offer it for sale, so here you go. If there's enough interest, I'll do another run of them as a kit. You could use it for your project rig's VFO, as a test source for your receiver, or as a frequency reference for your lab.
The gist:
- AD9951/2-based 140bit, 400Msps DDS VFO
- 50kHz-150MHz coverage with <1Hz resolution
- >52dBc SFDR from 0.01MHz to 150MHz
- Phase noise <-120dBc at 100Hz (10MHz out)
- Phase-lockable to your GPSDO or other favorite frequency reference
- 0.28ppm absolute frequency accuracy (!) when not locked to external reference
- Up to 18dBm (63mW) output
- Integrated elliptic LPF for harmonic suppression
- Can use comparator output of AD9952 if you want a square clock output to drive a mixer
- STM32 microcontroller
- USB and serial (3.3V) interfaces for PC control
- 96x16 OLED display
- Intuitive push-and-turn interface
- Four-layer, professionally-designed PCB with lots of attention to isolation and signal integrity
As shown, it's built like a Cadillac -- the LO is a Crystek 100MHz VCXO with ludicrously low phase noise, and the reference oscillator is a Connor-Winfield TCXO with 280ppb accuracy. Those parts cost about $30/ea, so it gets pricey fast. BUT in case that sounds like crazy talk, I designed the board to be able to use much cheaper parts as well, if you don't need that kind of performance. You can use a $3 10MHz TCXO as the reference with no 100MHz xtal, at the cost of somewhat worse phase noise and frequency accuracy. You can combine the digital and analog power supplies so
... keep reading on reddit ➡Edit: added link https://www.youtube.com/watch?v=Q3oItpVa9fs
Hopefully this hasn't been posted here before. Just found this really cool video demonstrating cymatics with some different synthesizers. also, check out the behind the scenes for the different experiments. http://nigelstanford.com/Cymatics/Chladni_Plate
This is a quick question, but I am having trouble finding an answer when I google it (perhaps I am not asking the right question).
Is the clicking sound produced due to the amp not being able to produce such a LF sound, or due to the fact that our ears can't process it properly?
Been trying to figure out how to get this beepy/delayed synth tone at the beginning of this song. It was a pretty popular sound in the mid 2000s but this was the only example I could find.
Clocks and Timepieces by Search The City
If anyone can help me at least accurately describe the sound and point me in a research direction that would be great!
I have a guitar student who was interested in getting into pedals for the first time, and asked me lots of questions about it. After spending most of a lesson just answering, I figured it'd be easier to write him an overview.
My whole band helped out with effects, pedal examples and musical samples of where they can be heard. My student's a big fan of Metallica, Green Day and Nirvana, so the examples I picked lean in that direction.
This is what I wrote him:
There are a few broad categories of effects. Drive pedals are generally to do with your core tone, such as giving you a great distortion sound or boosting it so your solos can be heard better. Modulation pedals, like chorus or tremolo, make constant cycling patterns in your sound, to create more interesting textures, especially when playing without distortion. Echo pedals add space to your tone, making the whole thing sound bigger. Dynamics pedals typically fix problems, like getting rid of hum or stopping your loudest notes from damaging your speakers. And admin pedals make sure the little details are in order, like splitting the signal where necessary or keeping you in tune.
Here I’ve separated them out into sections:
Drives
EQs
Dynamics
Modulations
Pitch Shifters
Echoes
Admins
Drive Effects
Drives add more gain to your signal, like a second amplifier before your main one. These fall under four categories, based on how much they alter your sound:
- Boost – makes the sound louder without affecting the tone much. Good for making a lead melody stand out, or pushing your amp a bit harder (and so making it distort a bit more) for solos. I use one for playing clean solos. A famous example is the MXR Micro Amp.
- Overdrive – adds an edge to the sound, making it break up. Overdrive and distortion are very similar, and there isn’t a definite line between them. Generally overdrive is a bit lighter, and responds more to how hard you pick (as in if you pick a note harder, it’s much more distorted than if you pick a note lightly). The classic example is the Ibanez TS808 Tube Screamer, a more modern one is the Earthquaker Devices Talons Overdrive.
Danzig: Mother '93 (rhythm)
Stevie Ray Vaughan: Pride and Joy (lead) - Distortion – generally thicker than overdrive, and capable of distorting the notes even if you pick very lightly. Comes in flavours ranging from the grungy Pro Co Rat to the all-out met
A few months ago, I posted my HackRF SuperCluster. Now I would like to share some results and implementation details.
Project history and goals
Initially, I had a few HackRF boards lying around. I decided to buy additional boards and try to build something fun and useful.
It was very interesting to receive a wider bandwidth with cheap SDR boards. USRP is cool but too expensive.
8 HackRF boards could provide up 160 MHz of monitoring bandwidth.
HackRF setup
I found that it's possible to synchronize multiple HackRF boards. Then I came up with the following layout:
https://preview.redd.it/gub81glm17281.png?width=1081&format=png&auto=webp&s=80fa2e88f22e2b765424c6a10dbc059d1970b239
All the boards are clocked from the same stable phase-correct 10 MHz sources. Also, there is a 1PPS signal that helps to sync data sampling.
According to this paper, this should provide a decent level of synchronization between the boards.
This sync mechanism requires the latest HackRF firmware release (at least 2021.03.1).
GPS block it's a GPS disciplined oscillator that provides 10 MHz square and 1PPS 1Hz signals.
The RF Splitter introduces a lot of fading, so additional LNA is crucial. As shown below, I'm using two LNA and a high-pass filter for my satellite monitoring setup.
HackRF boards could provide the 10MHz clock output and create a daisy chain setup. But this also could introduce delays and phase instability.
I decided to build a separate clock distribution amplifier and provide eight phase-coherent clock lines.
https://preview.redd.it/91wt5u7yl7281.jpg?width=900&format=pjpg&auto=webp&s=47ecf081c51fc7a5b3d62e3b5e1b05bfabdd0d92
https://preview.redd.it/chmjs8gwl7281.jpg?width=900&format=pjpg&auto=webp&s=b590e9540134e22ff0b6be78d852562319c41cf5
https://preview.redd.it/jrcxjyfzl7281.jpg?width=900&format=pjpg&auto=webp&s=11bcb66a0d2228df915ac0097548dcbf22a2ff4a
You can find more information about this device on my blog:
https://olegkutkov.me/2021/04/10/1pps-square-clock-8-channel-distribution-amplifier/
[https://olegkutkov.me/2021/08/19/housing-for-the-1pps-square-clock-8-channel-distribution-amplifier/](https://olegkutkov.me/2021/08/19/housing-for-the-1pps-square-clock-8-channel-d
Hi, this semester I am taking a course for programable electronics systems(FPGA mostly). My university has a board called Nexys A7: FPGA Trainer board and I would like to make a simple project using up-counter. Since I am a beginner I would like to know some projects ideas using that up-counter from this sub. Thank you
I understand learning a DAW is basically just putting in the reps and learning the technology, but how do I learn about instruments. I have no idea what sounds make what noises? I just know what I like. Any help on this would be greatly appreciated.
Hello fellow robots,
I'm working on an audio device (sort of an additive synthesizer) that has to generate a lot of sine waves in real time.
Right now I have a DDS setup to generate 10 sines on an STM32F410 running at 100MHz. However if I add more I run out of room and other processes aren't being executed. The time spent calculating and executing the DDS takes too long.
An option is to lower the sampling frequency. But that will introduce aliasing the lower I go, which is not desirable.
I guess my question is — Is there a good way to solve this? Brute force? Just get a better specced STM32 and crank up the MHz? Switch to another method? I've been looking at something like inverse FFT, but from what I understand if I want precision it'll also be heavy to compute. And I'd prefer to have at least 1Hz control over the sine frequency. Or is there another way to go about this?
Hey guys. I really love the tone of string instruments like cello. Is it possible to synthesize such timbre? Do not have to replicate certain instruments. The point is to catch the feeling of drone and vibration from the string. Thanks a lot!
Hello r/aphextwin! For the past couple of years I have been trying to get into IDM, looked for recommendations online and listened to some of the classics but it never really clicked with me. Until I heard Tri Repetae and settled on Autechre as my go to band. And as of the start of the pandemic I have been getting into squarepusher and fourtet but for me that's more like party music instead of brain music like Autechre. Wow I officially became that guy 😅
Anyways, so far I have listened to ambient 1 and the rd james album multiple times over my IDM journey and I often do work or while I listen so I don't fully get into it and mostly just move my head to the beat. But somehow I have never had this holly shit I gotta stop and listen moment as I do with other IDM guys.
I guess I have gotten used to the modern autechre sound because I really like and expect darker sounding tracks, to me aphex tends to sound sharper and brighter in frequency content than ae and for me that is a turnoff. I kinda have aphex inside a box in my head where Richard's work sounds like faster acid house and it's a turnoff for me because I like IDM that feels separate from "the world". Separate as in it doesn't sound like a sampler and a synthesizer going thru delay and reverb doing 16ths.
IDK, what are those tracks or albums that are really out there? what tracks or albums give you this feeling that you don't have any idea how you would get those sounds or program those sequences? Am I really just looking in the wrong place by looking in aphex early-ish work? I just want to be blown away!
I don't want to step on anybody's toes here, but the amount of non-dad jokes here in this subreddit really annoys me. First of all, dad jokes CAN be NSFW, it clearly says so in the sub rules. Secondly, it doesn't automatically make it a dad joke if it's from a conversation between you and your child. Most importantly, the jokes that your CHILDREN tell YOU are not dad jokes. The point of a dad joke is that it's so cheesy only a dad who's trying to be funny would make such a joke. That's it. They are stupid plays on words, lame puns and so on. There has to be a clever pun or wordplay for it to be considered a dad joke.
Again, to all the fellow dads, I apologise if I'm sounding too harsh. But I just needed to get it off my chest.
I just released version 0.5.4 of OctaSine, my free and open source frequency modulation synthesizer VST plugin.
Improvements in this release:
- Pass key presses back to the DAW for virtual keyboard support on all platforms (as long as your DAW implements it). This was previously only done on macOS.
- A lot better performance of the graphical interface on Windows (and somewhat better on macOS)
- Better support for high DPI screens on macOS and Windows
- Fix bug where closing plugin window on macOS would cause a crash
- Various graphics-related stability and hardware compatibility improvements
Ever since I learned about Fourier series and how they relate to timbres of musical instruments, I’ve been taken with the idea of trying to find a way to quantify the specific resonant harmonics and frequency of a given instrument in order to analyze that information and do things like write a song where I have harmonies emphasizing major overtones of the melody, or even something on a grander scale, like feeding that data into a neural net to make more realistic synthesizers. However, looking into it, I haven’t found much information on this concept, nor many ideas about how one would go about collecting that kind of data. I’m relatively new to the art of sound design so I was wondering if there were any major tools that could be used for that kind of purpose that I might’ve been unaware of. Thanks for the help.
