The average day at the office for David Karon in the laboratories of KHDK Electronics is, it would seem, not so average.

“Banshees and ghouls and demons,” he tells Decibel. “We pretty much knew from the start of this project we’d be rolling in that realm of evil.”

The effort in question is the Ghoul Screamer, a supercharged, lithe, insanely versatile, more sinister take on the classic tube screamer pedal painstakingly developed and perfected over a period of three years with company cofounder/Metallica lead guitarist Kirk Hammett — and set to be unleashed, appropriately, on Halloween.  

At KHDK the roles are fairly well defined. Kirk Hammett’s job is to be Kirk fuckin’ Hammett — basically to slay like he’s slayed for more than thirty years while dreaming up visionary, ineffable pathways to ever-greater sonic Valhallas.

Karon’s gig, meanwhile, is to translate that ethereal, beyond-the-five-senses awesomeness into the sort of engineer-speak that can lead to a final badass product here in the material world.

It is a partnership that worked when the pair first collaborated on a limited edition half stack for Randall Amplifiers shortly after being introduced to one another by mutual friend Scott Ian. And the mind-meld has only grown stronger since they reunited to summon forth from the depths the absolute best guitar pedals in the hard rock/heavy metal universe.

“I don’t know if I’d necessarily call it mystic, but when it comes to this stuff Kirk and I really do speak the same weird language,” Karon says. “And, for whatever reason, I’m able to take what we come up with in that language and make it something that other people can understand enough to put Kirk’s crazy, brilliant ideas into practice.”

It is a skill Karon has spent a lifetime developing. 

As a young teenage drummer playing in punk rock bands, he fiddled more with the knobs on the tiny Gorilla amps in the practice room more than the guitarists themselves would. “I would always be like, ‘There’s something missing there,” Karon laughs. “That’s where my obsession began—driving myself insane trying to achieve great tones out of this tiny little thing that just stubbornly sounds like shit.”

Those salad days are never far from Karon’s mind as he works on KHDK’s offerings.

“I always test on this crappy little solid-state amp just to make sure our pedals are going to sound great for everyone,” he says. “I want to be absolutely certain that whether you’re a pro plugging into a half-stack or a kid in your bedroom sitting in front of a cheap 15-watt beginner amp, you’re going to get more tone than what you were expecting or hoping for.”

And would the teenage rocker Karon be freaking out over putting shit with Kirk Hammett? Well, uh, of course he would. But to honor the process and the work grown-up Karon recognizes the need to “step back as a fan.”

“It’s obviously hard to do sometimes — I grew up loving Metallica and Kirk’s body of work is just unbelievable,” he says. “The thing is, you have to think outside that box because, while we want to honor what Kirk has done in the past, he’s a very vital artist and we’re trying to achieve new things and move forward into the future.”

Here’s what the ghoulish future looks like for current and aspiring shredders: Three standard controls — drive, tone, volume — enhanced by five more switches—bass, high, body, compression, and foot.

Through it all, the goal was to take versatility to the next level without sacrificing accessibility.

“We definitely didn’t want to put 600 knobs on the pedal just to be able to say, ‘Hey, look at our 600 knobs!’” Karon says. “I didn’t want people to hit a switch and say, ‘That did nothing. Why is it there?’ We really fine-tuned all these switches to make sure each one contributed to the variety of total ranges you can get. Actually, we were going to lock a lot of those switches into the circuit, but then Kirk said, ‘Man, I’m finding many tones on this. We need to leave all five switches.’”

Karon and Hammett found partners up for the challenge of meeting these exacting standards in head engineer Antonin Salva and a family run manufacturer in Paducah, Kentucky where a real live guitar player tests every last pedal before it is loaded onto the truck.

“We haven’t rushed anything,” Karon says. “We could have easily put together a very basic pedal, put Kirk’s name on it, and gone to any Chinese manufacturer and, we’d have been done with it years ago. That’s not what we formed this company to do, though. We really want every pedal we do to be extra special. That takes time. Sometimes a certain combination sounds great in your head, but sounds horrible in the circuit. There’s a lot of trial and error. There’s a lot of effort. But even though Kirk’s in the biggest band in the world, we think of this, like our manufacturer, as a small business that has to prove its worth every day. We want to be seen as just a couple of guys creating some really great stuff.”

There are signs that the process is working.

“When we put in for our UPCs and 666 popped out in the code,” Karon says, “we were like, ‘We must be doing something right.’”