Don posted Jun 9, 01:09:

At least reverb?


remi posted Jun 12, 15:10:

Anyone knows of a way to implement audio effects with python ?

That would be neat but I don't know if the Raspberry Pi could handle it...

Or it could also be interesting to add a separated hardware (arduino ?) to manage the effects.
Anyone knows open hardware solution for synth effects?

rotylee posted Jun 12, 15:18:

continued research into cheap and easy DSP approach
has lead me to the new

and the idea that an entire show can be done with people connected little devices with touch screens doesnt have to be i-Crack any phone tablet pc or mac raspberry pie like devices, set top boxes with all the be processing done in html5, Java Script and some libraries.

need to figure out the best low price platform with high quality audio


WebRTC is a free, open project that provides browsers and mobile applications with Real-Time Communications (RTC) capabilities via simple APIs. The WebRTC components have been optimized to best serve this purpose.
Our mission: To enable rich, high quality, RTC applications to be developed for the browser, mobile platforms, and IoT devices, and allow them all to communicate via a common set of protocols.
Open-source JavaScript framework for developing audio effects with Web Audio API
Pedalboard.js is a ground-breaking, first of its kind, novel open-source JavaScript framework for developing audio effects and applying them to sound sources–and it's particularly good at guitar effects.
The API and all the abstraction is built around the concept of guitar effects — pedals and stomp boxes, pots and switches.
You design your pedal with the powerful Web Audio API, attach pots and switches to it, style it via CSS3 and voila.
Bring multiple pedals together to create a pedal board, easily adjust their settings and routing. Prepare as many pedal boards as you'd like, e.g. for your favorite styles. Easily switch pedal boards for a completely different sound.
Finally, a complete guitar effects stack, completely customizable, in your hands.
SoundTouch Audio Processing Library
SoundTouch is an open-source audio processing library for changing the Tempo, Pitch and Playback Rates of audio streams or audio files. The library additionally supports estimating stable beats-per-minute rates for audio tracks.
Tempo (time stretch): Changes the sound to play at faster or slower tempo than originally without affecting the sound pitch.
Pitch (key) : Changes the sound pitch or key while keeping the original tempo (speed).
Playback Rate : Changes both tempo and pitch together as if a vinyl disc was played at different RPM rate.
Gibberish - HTML5 Audio
charlieroberts/Gibberish - Fast, JavaScript DSP library that creates JIT optimized audio callbacks using code generation techniques
Gibberish Tests
charlieroberts/Gibber - An audiovisual live coding environment for the browser by Mr. Charlie Roberts
Gibber Demo - The Web Browser As Synthesizer And Interface (pdf)
Sound processing / Web audio API
Web audio API libraries
WAAX, Web Audio API eXtension,
Gibberish, a fast audio API for browser based audio content (JIT), https://github.com/charlieroberts/Gibberish
Flocking, SuperCollider-like declarative synthesis toolkit, https://github.com/colinbdclark/flocking
SubCollider, SuperCollider-like functional synthesis toolkit, http://mohayonao.github.io/subcollider.js
Timbre, JS library for Sound Programming (SubCollider.js underneath), http://mohayonao.github.io/timbre.js
Audiolib, audio tools library,
Audiolet, JS library for real-time audio synthesis and composition, https://github.com/oampo/Audiolet
Audiolet2, clarifications on current implementation regarding WA use https://github.com/oampo/Audiolet/wiki/Audiolet-2
KievII, GUI and audio/DSP JS library for web and mobile applications,
Web audio API utilities
WAAClock.js, A comprehensive event scheduling tool for Web Audio API, https://github.com/sebpiq/WAAClock
WebAudioX, Web audio API helpers (start point code?), https://github.com/jeromeetienne/webaudiox
Allen, Utilities for the Web Audio API (js methods),
AudioContext-MonkeyPatch, polyfill for web audio API, https://github.com/cwilso/AudioContext-MonkeyPatch/blob/master/AudioContextMonkeyPatch.js
Web audio API Server Side
A server side implementation on web audio api with node.js,
Non Web Audio API libraries
DSP.js, a (old Mozilla) comprehensive DSP library for javascript, https://github.com/corbanbrook/dsp.js
Hyacinth, interface specification for plugins,
Faust to Web Audio API JS
Video JS
SooperLooper is a live looping sampler capable of immediate loop recording, overdubbing, multiplying, reversing and more. It allows for multiple simultaneous multi-channel loops limited only by your computer's available memory.

joseph posted Jun 13, 10:57:

Thanks for these links @rotylee, they will be very useful when designing online in-browser instruments!

About effects, you would be for a "web" network-oriented approach?

I was more thinking about direct effect embedded in the box / in the program itself.

Adding a convolution reverb should be technically possible, we'll need to try and see how much CPU it uses...

Have some of you experience with implementation of a convolution reverb algorithm?

Sparky Lectric posted Aug 4, 19:09:

the easiest way is to use an effects processor, can be as basic as a guitar pedal,such as fishman reverb, or a berhinger reverb pedal, to something like a VOX tonelab or a Roland/Boss GS-10. These are designed to do nothing but process sound, and have knobs and indcators to let you know what you are doing, with the tonelab and gs-10 you can save your presets to custom presets so you can easily reproduce a sound you like.

The other simple and cheap (fairly) is a ROland Micro-cube amp, which has built in effects, like reverb,tremolo,delay and chorus, flange and phaser, and has a record out jack so you can plug it into a recorder/recording interface or into a power amp and use it as a preamp for live performance. A used micro-cube is around 75$ in the states. There is a simple mod you can do that will allow you to use the record out and the speaker at the same time, so you can monitor yourself without using headphones, takes about 20 minutes and involves soldering a switch into the circuit.

Reverb - properly done is difficult to implement cheaply electronically, that's why its easier to buy a circuit already designed and tested like the tonelab or gs-10 or a guitar pedal. BTW both the tonelab and the Gs-10 provide a rotary speaker effect similar to a Leslie rotating speaker cabinet which is quite nice for guitar and organ work.

its either an external box or create a sample set thru a device with reverb on the samples and save them with reverb already baked into the samples.

opus.quatre posted Aug 4, 20:13:

Anout Reverb, Erik tried and appreciated Freeverb,and implemented it in his own sampler box..
http://www.nickyspride.nl/sb2/ see his "manual"..
In his words: " Freeverb
Full implementation of freeverb (in C++) is working, All parameters can be freely assigned to midi CC.
I'm pretty critical to reverb, but I'm astound by the quality of the verb. Very useful!!! Full floating
implementation, hardly any grain in the tail."
I suppose someome.else, on this forum, has tried it amd cam give his opinion..
I.suppose it would be good if there was an "on/off" on the box to.easily toggle it on or off..
And I'm not a robot, still not..

Sparky Lectric posted Jan 12, 18:37:

I found a new (at least to me) daughter card named TrigAudio BVT16. It is 10$ usd plus 10$ shipping - so 20$ total from ebay:
I just ordered one so in 3 weeks or so I should have it in my hands. There is a 7 page data sheet for it.
it appears to have 3 diffent modes - offering different effects.
mode 1 for DJ offers 16 programs various phaser,flangers delays and reverbs, an auto wah and a gated reverb.

mode2 for mixer offers 16fx -reverbs,chorus,delays,flanger,phaser,and echo
mode3 for guitar offers 16fx chorus,flanger,phaser,tremolo,reverbs,gate,delay,filter,
octave up, octave down, and modulate.
it offers stereo or mono input and output.

looks to be smaller than a pack of cigarettes and it has two sets of pin headers for i/o and control and display. looks like it will need a couple rotary encoders, a 7 segment led, and some jacks and a power supply to make it functional. Might be cool to add it to the samplerbox.

here's the specs:


For mixer/guitar amp./ DJ equipment and other devices which need sound effects.

●True stereo performance sound quality
●16 programs of effects
●reverbs, echo, phaser, chorus, flanger, etc. ( can support Tap delay )
●Integrated the major components, control interfaces, and strengthen the electronic circuit design, also with the Breitling Replica Navitimer display circult, for example: 7-segment LED and LCM 16*12,that can save your bom cost
●20/27 bit digital signal processing with 24 bit AD/DA converters 192 kHz Sample Rates Supports
●Programs run at 128 instructions per word clock. (6 MIPS @ 48 khz sampling frequency)
●32k location Static Ram provides over 0.68 sec of delay at 48 kHz sampling frequency
●2input and 2output
●low power 5V operation
●ROHS compliant (PB-free)


Analog input :2
Input level :2.8Vp-p Max
Output level :2.8Vp-p Max
DSP arithmetic :20 bit/27 bit
AD/DA conversion :24 bit/48kHz
S/N ratio (A-weighting) >95dB
THD+N 0.08% Replica Breitling Bentley
Frequency response (Fs=48 KHz) 20 Hz - 20 KHz (+/- 1 dB)
Power supply 5V 90mA (without display)

here's a youtube video of the sound.


leon posted Jan 14, 13:24:

@Sparky Lectric
Im really curious how this is going to work!
I was searching for something simular hope this works.

Achben posted Jan 21, 00:47:

Anyone know if the 7 segment display is common anode or cathode?


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