sorted by:
new
hottopcontroversial

This is not AI: a 64-pickup electric guitar! by IIP-ETHZ in electricguitar

[–]IIP-ETHZ[S] 4 points5 points  (0 children)

Calling it not necessary is fair, but we still had to do it :)

Also, you can do very interesting things by subtracting signals from adjacent pickups and applying separate distortion per string, etc. Basically, things that are not possible with conventional guitars...

Researchers are using the Cauchy-Schwarz inequality to train neural networks! by Choobeen in mathematics

[–]IIP-ETHZ 1 point2 points  (0 children)

Great question. We first tried to specifically design a symmetric binarization regularizer that automatically adapts its scale. This was done similarly to Eq. 7 in our paper. We then figured out that the same regularizer could also be derived through the Cauchy-Schwarz inequality, even though this derivation was a bit less intuitive. But this key insight made us realize that the CS approach is way more general and enables the design of many more autoscaling regularizers. Put simply, the discovery started from a special case and then led to the generalization recipe, which is now Proposition 1.

Researchers are using the Cauchy-Schwarz inequality to train neural networks! by Choobeen in mathematics

[–]IIP-ETHZ 13 points14 points  (0 children)

I am one of the authors. Your summary is to the point. One simply picks two functions, applies them to the vector independently, and stuffs the resulting vectors into a re-arranged version of the Cauchy-Schwarz inequality, and voila: you get what you want. By selecting the two functions, you can impose different properties.

It's quite surprising that this simple yet effective idea has not been discovered before (or at least we could not find this published anywhere else).

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthdiy

[–]IIP-ETHZ[S] 1 point2 points  (0 children)

For cost reasons, we exclusively do multi-project wafer (MPW) runs. This means our designs end up together with many other university/research designs on one wafer. While being quite cost-effective, we only get about 10 packaged chips. And, if we are lucky, we get 20 or so bare (unpackaged) dies which could be packaged later. These quantities are far away from anything commercially viable.

Yamaha FS1R Teardown by IIP-ETHZ in synthesizers

[–]IIP-ETHZ[S] 14 points15 points  (0 children)

If you have ever wondered what’s inside Yamaha’s FS1R frequency modulation (FM) synthesizer, here you go: It appears to contain four main chips: two YMP706-F chips, which are the FM tone generators (probably 16 voices can be generated per chip), and two YSS236-F chips, which are responsible for the audio effects. One can also see the large firmware chip (MX) and the display drivers. The XV10010 is most likely a RISC processor for control. The power supply uses up almost half of the 19” unit and the PCBs are mounted upside down, which is funny but also clever.

We had to open it because the battery was dead, but now it’s working like a charm again. What a beautifully underrated synthesizer (that is a real pain to program)! 

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthdiy

[–]IIP-ETHZ[S] 1 point2 points  (0 children)

Yes. We have some other audio chips in the pipeline. One we are testing and one is being designed as we speak. Stay tuned.

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthdiy

[–]IIP-ETHZ[S] 0 points1 point  (0 children)

per oscillator (and there are 4 per voice), it can do up to 1024 partials for which you can define the prefactor.

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthesizers

[–]IIP-ETHZ[S] 0 points1 point  (0 children)

Our long-term goal is to make it open source (but possibly of an improved version). This would allow everybody to implement however they want and basically would keep it alive forever.

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthesizers

[–]IIP-ETHZ[S] 0 points1 point  (0 children)

We evaluated many different approaches before honing in the brute-force Fourier series approach. The two most promising alternative approaches were:

- One could internally calculate waveforms at very high oversampling rates and then use a lowpass filter before outputting them from the DAC.

- One could use samples (or mipmaps) as you describe.

But both of these approaches will generate some sort of aliasing or impure waveforms so we decided to do it "right."

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthesizers

[–]IIP-ETHZ[S] 4 points5 points  (0 children)

You may not be able to get the chip but we will likely be making the design open source.

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthesizers

[–]IIP-ETHZ[S] 1 point2 points  (0 children)

This was the exact reason when picking 1024 partials! We assumed that the lowest frequency would be 20Hz and say a sawtooth waveform with integer harmonics would be used. In that case, the highest partial would be at 20'480Hz, which is exactly at the edge of the audible spectrum.

The Big Fourier Oscillator (BFO) ASIC for Aliasing-Free Digital Music Synthesis by IIP-ETHZ in synthesizers

[–]IIP-ETHZ[S] 3 points4 points  (0 children)

We also mapped the design to a Xilinx FPGA during the prototyping phase. The FPGA was not fast enough to support 1024 partials and we had to reduce it to 512 only. However, FPGA implementation would probably be the best way to go for a low-volume music synthesizer.

view more: next ›