Audiophile Circuits League (ACL) is a collective of musicians and engineers based in Berlin, Germany, developing and manufacturing electronic music equipment since their founding. The company specializes in Eurorack modular synthesizer modules and related audio equipment, going beyond classic circuit designs to produce highly innovative and musical devices. ACL maintains uncompromising quality standards, using carefully selected components with all design and assembly completed in Germany. Their product line includes VCOs, VCFs, audio interfaces, MIDI modules, power supplies, and complete systems like the ACL System 1 Eurorack Synthesizer. Notable products include the popular Sinfonion and various specialized modules for the modular synthesis community. The company maintains active social media presence and distributes products through specialized music equipment retailers worldwide, emphasizing community-driven innovation and user feedback.