Prague-born Deml grew up in Germany, where he founded his first band (Quest) at the tender age of 16. After completing his schooling he moved to the USA, studying at the Guitar Institute of Technology in Los Angeles alongside luminaries such as Larry Carlton, Scott Henderson and Paul Gilbert. Just two years later he was already teaching at the Institute himself and playing as a tour and session guitarist in California, including work on projects by Carmine Appice and Randy Jackson. After five years his residence permit expired and he returned to Europe.

In 1993 he teamed up with keyboard player Ralf Hildenbeutel to set up the ambient-meets-guitar project Earth Nation, which a year later caused a stir at the Montreux Jazz Festival. In the following years, Deml evolved into a sought-after session and live musician. He now has over 300 sessions to his name – including work for Kingdom Come, Nena, Rick Astley, Snap and Laith Al-Deen. He has also toured with Saga, the Rödelheim Hartreim Projekt and Simon Collins, to name but a few.

To date, he has released five studio albums with Errorhead – the last being the awesome "EVOLUTION" (2014) – plus a live album and a concert DVD. He has also lived out his passion for jazz rock in the Electric Outlet project.