According to his website, Pascal's interest in electronics began at the tender age of 12. It eventually led to a double degree in electronics followed by R&D work for companies like Eurocopter now Airbus, the torpedo experts Eurotorp, aeronautics firm Dassault and oceanographic outfit Ifremer. By 2012 he launched Kallyste to devote himself purely to audio. Important to him are true timbres which rely on transient speed, very wide bandwidth, a very low noise floor and the proper distribution of harmonics. Yet his aim is truth rather than pleasing colourations. This has him collaborate with musicians and recording professionals.

His design work begins with concept studies, progresses to circuit diagrams, the selection of parts and their ideal layout. That then determines the necessary chassis dimensions. This leads to mechanical renders and only at the very end to cosmetics. His PCB avoid robotic population. His favoured gain circuits work in class A/B to avoid the energy inefficiency of class A and the issues of class D. He pursues simple purist circuits to shun needless complexity. "The more parts we use, the greater the number of interactions we must manage". Like a terse rather than lengthy letter, he views the real challenge the reduction of any circuit diagram down to its bare essentials.

For home use, he doesn't believe in balanced circuits. He also prefers pentodes to triodes and picks over-spec'd military-grade variants which are operated far below their full potential. It's how he can offer a transferrable 10-year warranty on tube gear. His choice of rectifier tubes is predicated upon avoiding the switching peaks of silicon rectifiers. His pursuit of the best noise floor and circuit speed relies on rigorous testing, insuring that his circuits can't oscillate despite great bandwidth; and mirror-imaged channel separation in dual mono. His transformers are made to his specs so not off the shelf. All manufacturing and production occurs in-house except for the PCB which outsource to a French contractor; and the transformers. Other parts vendors include Dale, Kemet, Nichicon, Panasonic, Vishay and more.