Zack Ohren - Lead Guitar

Zack Ohren was born on June 9, 1981, in Oakland, California. He is an American musician, producer, recording engineer, mixer and mastering engineer who has spent most of his career working within the San Francisco Bay Area metal scene.

Although best known for his extensive studio career, Ohren is also a multi-instrumentalist who has played guitar, bass and drums in numerous bands and projects.

Early Career

Ohren became interested in both playing and recording music at an unusually young age.

As a teenager, he began experimenting with computer-based music production and was only around 15 years old when he composed music for the Nintendo 64 snowboarding game Twisted Edge Extreme Snowboarding.

He subsequently became increasingly involved in the Bay Area underground metal scene, both as a musician and behind the recording console.

Myotonia

One of Ohren's earliest significant bands was the progressive metal group Myotonia.

Ohren played drums with Myotonia from approximately 2001 until 2008, establishing himself as a performing musician while simultaneously developing his career as a recording engineer and producer.

During this period, studio work increasingly became the central focus of his professional career.

Castle Ultimate Studios

Ohren established Castle Ultimate Studios together with engineer Aaron Hellam.

Operating from several locations around the Oakland and Emeryville area, Castle Ultimate became closely associated with the Northern California metal and hardcore scenes.

During the 2000s, Ohren recorded, produced, mixed or mastered an extensive list of bands including All Shall Perish, Light This City, Animosity, The Ghost Inside, Warbringer, As Blood Runs Black, Decrepit Birth, Suffocation and many others.

One of his most significant early relationships was with Bay Area deathcore band All Shall Perish.

Ohren worked on the band's debut album Hate. Malice. Revenge in 2003 and subsequently worked on The Price of Existence (2006), Awaken the Dreamers (2008) and This Is Where It Ends (2011).

The extensive body of work produced at Castle Ultimate helped establish Ohren as a sought-after producer and engineer, particularly within extreme and technically demanding forms of metal.

Midnight Chaser

Despite the increasing demands of his studio career, Ohren continued performing as a musician.

He played bass with traditional heavy metal band Midnight Chaser before switching to lead guitar around 2012.

Ohren remained with the band until approximately 2014 and played lead guitar on their 2014 album Lion's Choice.

Machine Head – Studio Work

Ohren eventually developed a particularly close working relationship with fellow Oakland band Machine Head.

He worked on the band's 2018 album Catharsis, receiving production, mixing and mastering credits.

The relationship continued during the creation of Machine Head's tenth studio album, ØF KINGDØM AND CRØWN, released in 2022.

Ohren co-produced and engineered the album alongside Robb Flynn, working extensively with the band during the recording process.

He again worked closely with Machine Head on their eleventh studio album, UNATØNED, released in 2025, serving as co-producer alongside Flynn.

By this point, Ohren had become an important part of Machine Head's extended creative and production team, despite not being an official member of the band.

Darkness Everywhere

In 2022, Ohren became the bassist of Bay Area melodic death metal band Darkness Everywhere.

The group was formed by guitarist Ben Murray of Light This City and also featured vocalist/guitarist Evan Henkel.

Ohren played bass on the band's debut EP The Seventh Circle, released in 2022.

He continued with Darkness Everywhere as the band released additional material, including the 2023 single "The Glow of Haunted Existence" and the 2024 album To Conquer Eternal Damnation.

Machine Head – Touring Guitarist

Ohren's long studio relationship with Machine Head eventually resulted in him joining the band onstage.

In 2025, Machine Head guitarist Reece Scruggs temporarily stepped away from touring after his father was diagnosed with lung cancer.

Former Machine Head guitarist Wacław "Vogg" Kiełtyka returned to cover the majority of the band's European and UK summer shows, but scheduling conflicts prevented him from appearing at every concert.

For selected dates where Vogg was unavailable, Zack Ohren stepped out of his usual behind-the-scenes role and joined Machine Head as a temporary touring lead guitarist.

The arrangement was particularly notable because Ohren was already intimately familiar with Machine Head's music through his years of studio work with the band.

His appearances made him one of the relatively small number of musicians to have both worked extensively on Machine Head's albums behind the recording console and later performed as part of the band's live lineup.

Ohren remained a touring substitute rather than becoming a permanent member of Machine Head.

Current Career

Zack Ohren continues to work as a producer, recording engineer, mixer, mastering engineer and musician in the San Francisco Bay Area.

Over a career spanning more than two decades, he has worked on hundreds of recordings for artists including Machine Head, All Shall Perish, Suffocation, Immolation, Warbringer, The Ghost Inside, Fallujah, Decrepit Birth, Cattle Decapitation, Aborted and numerous others.

Alongside his production career, he has remained active as a musician through projects including Myotonia, Midnight Chaser and Darkness Everywhere.

His 2025 appearances with Machine Head represented an unusual extension of a relationship that had previously existed primarily in the studio, taking Ohren from behind the recording console to the stage as a temporary member of the band's live lineup.