As all my experiments were completed with success so far, I was now able to add more effects to the chain by implementing the same well-tried principles. Based on my initial intention concerning the analog delay chain, I decided to add both a delay and a reverb effect to the patch. The delay is also based on the [delwrite~] and [delread~] objects and follows the principles of any usual digital delay pedal. The input signal gets delayed in the buffer with an amount between 0 and 3000 milliseconds which is then routed to the output. The input is also sent straight to the output where it gets mixed with the delayed signal. To create feedback, the delay signal is once fed back to the input, but as its level is always less than one its volume will decay over time.
To build the reverb, I first tried to use the [rev1~] object, thinking it was part of the vanilla library. After I uploaded the patch to Bela, it turned out to be unsupported, so I had to find a Vanilla-friendly solution. Following some research, I learned that Katja Vetter made a freeverb abstraction only with Vanilla objects, but I couldn’t find the original patch, only an adapted version by Derek Kwan. As this project was available on GitHub and free to use, I implemented it into my project. Similar to my delay line, this patch also uses a series of comb filters implemented with the [delread~] objects to modulate the signal. In addition, a low-pass filter is applied to the taps, creating the opportunity to attenuate the reverb. Having previously set up all the networking structures for the OSC protocol, all I had to do was add the new parameters to both the TouchOSC interface and the PD patch and everything was up and running.
