Darkglass mastermind Douglas Castro takes measurements on his first amplifier, a top-secret M900 prototype,
which hadn’t been announced as of this writing.

Darkglass Electronics

Based in Helsinki, Finland, Darkglass Electronics builds effects pedals for bass players. “Our primary goal is to tell bass players, ‘Be heard and be noticed,’” says Darkglass CEO and founder Doug Castro. “All of our effects and preamplifiers are about taking the bass sound to the next level so bassists can reclaim a more predominant role in their bands.”

“All of our effects and preamplifiers are about taking the bass sound to the next level so bassists can reclaim a more predominant role in their bands.” —Doug Castro, Darkglass Electronics

Originally from Chile, Castro started playing bass at 13, but opted to focus on electronics after high school. “The first circuit I designed was the Microtubes B3K, which is now one of our best-selling products,” he says. “Once I designed that one, everything took off from there.”


The B7K is a preamp, overdrive, and 4-band EQ for bassists.

Darkglass’ flagship is the Microtubes B7K—a souped-up edition of the B3K that’s available in both standard and Ultra versions. “The B7K is a preamp, overdrive, and 4-band EQ,” Castro says. “The Ultra has basically the same preamps, but you control the distortion separately with a second foot switch. You also have two mid controls—low and high mid—and each mid control has a 3-way selector switch.”


Kiriaki “Kira” Pavlidi at work. “We could not imagine any of our products without Kiriaki’s neat
assembling and soldering,” says Castro.

Although headquartered in Finland, the company is truly international. R&D and manufacturing is done in Europe, marketing and sales are based in Chile, and artists relations is in the U.S. “We have a 200 square-meter shop, and all the effects are built here in Finland,” Castro says. “The metalwork, chassis, silk screening, and laser engraving is all done here. We try to keep it local. We get the circuit boards from a few suppliers in different EU countries, but all the final assembly and testing is done here.”


Party time in Helsinki! Although headquartered in Finland, the company has offices in Chile and the U.S.

Darkglass artists run the gamut from metal to pop, and include Alex Webster (Cannibal Corpse), Tony Levin, Billy Gould (Faith No More), Dick Lövgren (Meshuggah), and Amos Heller (Taylor Swift). “I believe the product you make should work for different scenarios and should adapt to many requirements. We focus on products that can be used by anyone,” Castro says.


Enrique “Quique” Rangel solders a connection. All Darkglass effects are built in Finland in the company’s
200 square-meter shop.

But ultimately, it’s all about the bass. “I think bass players have always had a very shy role in bands for the most part—especially in rock and metal—and I would really like to see them take the lead a bit more.”

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