The Effectrode Helios Tube Fuzz pedal is a rare find. These pedals were a limited run with a production total of 200. However it does life up to it's reputation. It's great sounding pedal. Below is a description taken from Gilmourish.com. David Gilmour used one of these for his last album.
"The Helios is based on a vintage, hand-selected space-grade pencil tube and N.O.S. point-contact crystal diodes. This combo produce some incredibly dynamic fuzz tones, with a clarity and warmth that I’ve never heard from any fuzz pedal before. Most fuzz pedals, both germanium and silicon models, are often a tad too harsh, bright, thin or whatever but there’s none of that here.
It’s always hard to describe a tone but the Helios is no doubt a germanium-ish fuzz characterized by its warm and dynamic overdrive tone. At lower fuzz settings the pedal provides a transparent clean boost. With the fuzz slightly above noon the pedal reminds me more about the Tube Driver than a fuzz. Maxing out the fuzz takes you right back to the late 60s, with an incredibly rich and fat tone and a sustain that rings on for ages.
The Helios is not an overly aggressive fuzz but make no mistake – it can do some serious damage. Based on what guitar your employ this single pedal covers a diverse range of tones from early Stones, Hendrix, ZZ Top and Sabbath to Jack White, QotSA and The Black Keys.