I was going to add CPU load measurements but managed to fry the codec chip. Center negative 9V barrel jacks are dangerous with their exposed +9V ring. Must have touched something that instantly fried the chip. Luckily the T40 survived, had a polyfuse in the power input. Will replace the chip and repeat the test.
The
processorUsageMax for the reverb component was reporting about 5%. Also, i moved all the reverb allpass/loop buffers to DMAMEM, so it leaves plenty RAM for other uses.
With a stereo convolver running an over 6000 samples long IR (speaker simulation) + the stereo plate reverb i was getting about 25-30% load.
This is the base board i designed for the T40, it has the SGTL codec, midi i/o, 4 Pots, footswitch input, two leds and a few pin expansion pin header, like SPI for a small display. Oh, and analog bypass using CD4053.
It's a hobby project, which i'd like to open source. I'm building it mainly for my home studio/live looping rig. Something i'll put at the end of the chain, providing speaker simulation, reverb, track doubling and whatever else i'll come up with (wav player for drum loops maybe).
I'll create a new thread about it once i gather more project details.
Not sure if tweeter links will work here, but i posted an interesting reverb comparison when i was working on another project:
https://twitter.com/hexe_fx/status/1327263279455068165
At first i was trying to improve the freeverb by adding a slow modulation to the delay lines. This is a common technique to sort of "smear" the reverb tail, make it less echoey. It did improve the sound a little bit, but the noise/metallic ringing was still audible, only now modulated
So, in the end i started from scratch using a different reverb topology, which i often used with the SpinSemi FV-1 dsp. T40 opens up so much new possibilities. This won't be my last reverb for sure! Already thinking about a nice spring reverb simulation.
It sounds like it would port fairly easily to the OpenAudio_ArduinoLibrary (Floating Point Teensy Audio Library).
Yes, fairly easy. I plan to switch to OpenAudioLib anyway.