Is this it: https://github.com/mohayonao/timbre.js/ ?
(It says it's not maintained anymore)
What does it offer that Tone.js does not?
What does it offer that Tone.js does not?
Timbre lets you do more advanced stuff in a simpler way (less lines of code), although the last time I used Tone.js was a long time ago, so things might be different now.
Take a look at the Timbre.js examples!