Portland, Oregon-based electronic musician Daryl Groetsch started Pulse Emitter as a harsh noise project, but over time his music morphed into dark ambient/drone, and eventually Berlin School-style kosmische and new age. He has issued dozens of recordings on labels such as Digitalis, Aguirre, Hausu Mountain, and his own Expansive imprint, summing up his progress on the 2014 double-CD Planetary Scale Synth Hypnosis.

An avid collector of modular synthesizers, Groetsch began releasing CD-Rs as Pulse Emitter in 2004 and quickly became a fixture of the Portland noise scene. While some of his recordings and performances were bleak and punishing, others drifted out into more alien spaces, combining sparse, hypnotic drones with piercing, trebly feedback. He also created more soothing music, and in 2007, he initiated his Meditative Music series of albums designed for sleep, relaxation, and massage. He continued releasing noisy recordings for labels like Digitalis (Oppressive Nature) and Ultra Eczema (Decaying Ships), but by 2011, he had more or less shed the harsher elements from his work, and his music has only become brighter and more spiritual since then.

After releasing numerous LPs and cassettes on labels such as Aguirre, Immune, Cylindrical Habitat Modules, and NNA Tapes, Metal Postcard issued Planetary Scale Synth Hypnosis, a 2014 double-CD compilation. On subsequent releases such as 2015's Digital Rainforest (Beer on the Rug) and 2016's Through the Portal (Phinery Tapes), Pulse Emitter's work became more intricate, incorporating acoustic percussion and field recordings, as well as sophisticated digital programming. In 2017, Hausu Mountain released Mugen, Vol. 9, a split cassette with Brett Naucke. Xenharmonic Passages was released through Groetsch's Expansive label in 2018. He returned to Hausu Mountain with the 2020 LP Swirlings. ~ Paul Simpson, Rovi