The JOYO JF-17 Extreme Metal is a dark horse in the Joyo range.
With the combination of its three band eq and drive and level knobs you can get a wide variety of tones from heavy blues through hard rock to high gain metal. With the gain set at around 9 'o' clock using a bridge position humbucker you can get some excellent classic rock tones. Flick to the neck pickup and you get a thick, creamy sustain filled lead tone ideal for any heavy/rock blues lead playnig you'll be doing. With the right combination of EQ settings with the drive low you can even get some quite Santana-esque tones from this pedal.
Where this pedal is most at home is with the gain at 12 'o' clock or higher. At 12 'o' clock you get some brilliant hard rock tones reminiscent of Guns N' Roses, Metallica and Iron Maiden. Again using the 3 band EQ here will give you masses of variety. For a more 'metal' type sound why don't you try scooping the mids out slightly and adding a few more highs and lows.
Push the gain to 3 'o' clock and you get an all out metal onslaught. Make sure you scoop the mids and push the bass and highs and you'll be in metal heaven. Pinch Harmonics will fly off your guitar. A nice and tight low end heps keep any palm muted galloping riffs sounding crisp and clear. Throw your guitar into a drop tuning and chug away, this pedal stays tight no matter how low you go. Don't forget the divebombs if you have a tremolo equipped guitar.
The boost switch is best used on your neck pickup with the control between 9 'o' clock and 10 'o' clock. Kick this in at the start of your solo and it'll help increase your volume a little and add a nice bit of top end to really help you cut through the mix so everyone can hear those shredtastic solo's!!!
Housed in an Aluminium Alooy case the Extreme Metal is built to withstand everything you can throw at it gig after gig.