A manufacturer of modular synthesizer equipment based in Berlin, Germany. (The acronym stands for "Audiophile Circuits League".) ACL offers a small selection of analog modules in Eurorack format, including sophisticated VCOs with variable oscillator sync and multi-turn pots for tuning. ACL's lead product is the System 1, a pre-configured modular synthesizer with a selection of the company's modules. The case and power supply components of the System 1 are also available separately, as well as modules.