Presenting the Infinity System. We’ve come a long way. After many years of refinement, I think this latest iteration is ready for prime time. This is the final release-ready form.
For those who are just joining in, in a nutshell, Infinity is as a polyphonic sustainer. Meaning, all vibrating strings will keep on sustaining until they are muted. The system integrates a multichannel pickup and sustain drivers using multiple feedback loops, orchestrated by a microprocessor that manages the precise interplay between the pickups, strings, and the drivers.
The short demo video above has sustain control set to roughly 5. The audio from the pickups is captured and mixed as raw as possible. There are no effects except for a touch of reverb, and the Ascend VPU inserted in each channel, used solely for noise reduction with the virtual pickups bypassed. There is no EQ and no compression.
Infinity is not an aggressive sustainer. Technically, there is sufficient output drive to cause the strings to oscillate to fret-rattling levels, but the objective is to achieve a properly behaving and evenly balanced sound output across all strings and at various volume levels. The main idea is to perform further envelope shaping using post processors, as noted in the Infinity White Paper. In most cases, a sustain level of 4 to 7 is adequate. Let post-processing, such as dynamic ADSR envelope shapers for volume and timbre, and possibly waveshapers (e.g. overdrive and distortion), handle the heavy lifting.
The image below shows the actual raw envelope of the short demo above. It is easy to see how this envelope can be shaped using post-processing, by adjusting the attack and sustain levels to suit. What matters is that the strings continue sustaining indefinitely until you release them.
There is no harmonic mode either. The goal is to maintain a clean sustained fundamental frequency, with minimal harmonic shifting, across all strings and fret positions. We want it to sound as natural as possible, with no audible processing artifacts.
Assembly
The system has a small footprint, the size of a PAF humbucker. The output amplifier drives two coils: one for the treble side and one for the bass side. Thinner strings require more power to drive into oscillation due to lower magnetic mass. The treble driver coil takes care of the plain strings for up to three strings. The system is capable of up to 8 strings. The bass driver coil can drive three to five wound strings, using a suitably sized driver coil. The microcontroller balances the output drive across all strings to maintain smooth and even output levels via feedback from a Nu-Multi multichannel pickup.
The Infinity system is kept as simple as possible. There is a single “sustain” control via control voltage (CV) that determines the sustain level. Normally, the sustain level is controlled by a CV potentiometer. But since it’s just a control voltage, the system can also be controlled externally, e.g., via an expression pedal, for hands-free operation.
The diagram below depicts the system.
Block Diagram
Modules
The Infinity system is composed of three modules that snap together vertically to maintain a small footprint.
- The Driver module (rightmost board in the picture below) contains the amplifiers for driving the coils. These are linear class AB amplifiers specifically chosen to deliver clean, noise-free output.
- The MCU module (middle board in the picture below) contains the microcontroller, which includes provisions for flashing the firmware via USB.
- The Main module (leftmost board in the picture below) integrates the MCU module and the Driver module and connects them to controls and the Cycfi standard 19-pin output jack.
Availability
Thor
The Infinity system is integral to Thor, the carbon-fiber guitar with multichannel sustain. We’re nearing the completion of the initial batch and gearing up for the second batch, probably starting in November. If you want a ready-to-use Infinity system in the near future, consider getting a Thor. If you are interested, please send us a message, and we’ll gladly add you to the second batch waiting list.
Infinity Kit
At this point, I believe the Infinity system has reached a level of maturity and stability that renders it suitable for integration into other guitars. I will share details soon. For now, if you are interested, please email us as soon as you can, so I can add you to the Infinity waiting list. Please keep in mind that I can only release the Infinity Kit as a separate product if there is sufficient interest. Below a certain threshold (probably around 50 to 100 as a rough estimate for the initial batch), releasing it as a separate product will not be practical. And so, beyond expressing interest, please spread the word, so we can reach that target sooner. Infinity is not just a proof of concept. It is a fully working, fully tested system.