XYBA: Line driver and buffer based on the Centaur input topology and parallel op-amp design
Two stages utilize a dual parallel op-amp design to reduce internal voltage noise by 3 dB per stage. This achieves a total noise floor of approximately -123 dBu, which sits well below the measurement floor of standard audio test equipment. Gain is switchable between two fixed settings: 10 dB and 17 dB. Designed as an always-on device for studio applications, pedalboards, guitar, bass, synthesizers, drum machines, and DAW sidechaining.
Why This Device Exists
I have always been fascinated by the idea of having a secret weapon—an "if you know, you know" device that I could use as an always-on tone enhancer for my playing.
In parallel, as I'm studying electronics, I came across the concept written in Douglas Self's book about using parallel op-amps to reduce noise. And since I'm going through a lot of pedal schematics as well, I chose the Klon Buffer as the starting point and thought of the ways we can expand and enhance this circuit so that it gives you this little bit extra the Klon Buffer gives to the sound, as well as additional functionality to breathe life into my guitars.
So, instead of building another extreme device or a noise maker, I wanted to build something on the opposite side of the spectrum. A high-performance, studio-grade, very well-thought-out device that can be used with any rig and give that extra touch to the sound and to the playing for musicians.
The name of our line driver is Xyba—the name "Klon" shifted through a Caesar cipher. So, here comes the Xyba.
In parallel, as I'm studying electronics, I came across the concept written in Douglas Self's book about using parallel op-amps to reduce noise. And since I'm going through a lot of pedal schematics as well, I chose the Klon Buffer as the starting point and thought of the ways we can expand and enhance this circuit so that it gives you this little bit extra the Klon Buffer gives to the sound, as well as additional functionality to breathe life into my guitars.
So, instead of building another extreme device or a noise maker, I wanted to build something on the opposite side of the spectrum. A high-performance, studio-grade, very well-thought-out device that can be used with any rig and give that extra touch to the sound and to the playing for musicians.
The name of our line driver is Xyba—the name "Klon" shifted through a Caesar cipher. So, here comes the Xyba.
XYBA Overview
1
Buffer stage:
The input stage uses a Centaur buffer topology expanded with a dual parallel op-amp design, as outlined in Douglas Self's Small Signal Audio Design. Splitting the input signal across two parallel op-amp paths reduces internal voltage noise by 3 dB per op-amp.
2
Amplifier stage:
10 dB Boost: A sweet spot to add life and presence to the audio signal. 17 dB Boost: Additional output to push a clean tube amplifier slightly past the edge of breakup. Great for lead work, solos, or driving saturated gain stages further.
3
Routing & Bypass
Using the second switch, the entire amplifier stage can be completely bypassed. In this mode, the device functions solely as a pure buffer based on the Centaur schematic improved by the Douglas Self concept.
My notes and design
Xyba shipping starts in October 2026.
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