A look inside the REV33
I am a healthy skeptic (sometimes even a cynic) so I welcome all of the REV33 questions that we have received and the underlying desire to understand it a bit better.
This article will try to describe how the REV33 works and answer some of the frequent questions I have been asked.
What is inside the REV33?
The REV33 contains a patent-pending passive circuit inside which is designed to reduce the noise and distortion that gets into your earbuds, allowing you only to hear your audio as it was intended. The REV33 does not process or analyze the audio signal but rather utilizes some of the unique electrical characteristics of noise and distortion to reduce them.
One key objective of the REV33 is to keep the magnetics of the earbud as clean as possible.
Each REV33 is calibrated to the components in your specific ear-bud’s brand and model (example – JH Audio brand, JH16 model). We walk you through a simple selection menu on our website to so that you know which REV33 model is optimized to your specific earbud type.
What does it actually do to reduce distortion and how can it do this without processing the music or trying to differentiate music content from distortion content?
This is one of the most common questions I get. One key objective of the REV33 is to keep the magnetics of the earbud as clean as possible. We do this in a few ways:
1. Some distortion occurs in the bud itself (as opposed to distortion from the amplifier). This happens simply because the bud is magnetic with moving parts and it doesn’t always move perfectly with the audio signal. When this distortion occurs, the electrical characteristics of the distortion make it look like the bud is a generator, sourcing energy and pushing it back to toward the amplifier. This energy isn’t created out of thin air, it is actually energy that is ‘stolen’ from the original audio signal sent to the bud. The REV33 resists this energy that electrically appears to come from the earbud. Thus, we can resist current (and thus generation) of the distortion energy from the bud.
2. When an earbud moves, its impedance changes dynamically with its position. When its impedance changes dynamically, an amplifier with a small source resistance will produce different currents for the same output. For example, a 5 kHz tone will not render the same if the bud is displaced to a one location vs not displaced at all. The REV33 reduces the sensitivity of the change in position of the bud. This reduces the non-linear current that gets into the magnetics.
3. We also reduce high frequency noise generated by amplifiers or other system components. This includes class D amplifier noise that is shaped above 20 kHz as well as spurious tones that can be from high frequency clocks in the system or RF carriers. If you have a spectrum analyzer that goes up to 500 kHz or so, you will be surprised what you see in a lot of systems. Now, I concede that the ear cannot hear any of this energy however, this energy does get into your magnetics and reduces the capacity of your magnetics. You can measure how this unwanted energy creates intermodulation distortion with the music that you want to hear.
The above 3 processes work together to keep magnetics in the bud cleaner and reduce distortion. Because none of techniques require trying to analyze the audio signal and differentiate audio from distortion, there is no need to process, equalize or otherwise analyze the music. We simply keep the magnetics clean.
I hope this helps explain the fundamentals of the REV33. We are extremely excited about the technology because we are engineers by trade who love music. But what is truly exciting is the impact it is having on ear fatigue that is felt by musicians, sound engineers and band techs. Our motivation is to make things better and any distortion or noise that gets into your magnetics and muddies up the primary signal.
Dennis Rauschmayer, CTO of REVx Technologies, Inc