Leaderboard

The classic Black Sabbath guitar sound is a Gibson SG into a Laney valve amp - obviously that would be quite an investment, but one of the key differences in the tone will be the fact that the SG has two humbucking pickups*, and those do sound quite fundamentally different from the single-coil pickups in a Telecaster. It's a thicker, more bass-heavy sound, but you can approximate it by using the neck pickup, turning the tone down a little, and keeping the guitar's volume up. Now to your amp: does it have a "Gain", "Drive", or "Input Volume" control? Getting the overdrive under control can often be key to these things - in my experience, you can usually get a decent overdrive tone out of smaller practice amps, but they can also sound quite "fizzy" if you set the drive too high. Have a play with the overdrive at lower gain/drive/input vol settings - you want plenty of crunch, but you also don't want to lose the definition in your sound (if you don't have gain/drive/input on the amp, you can turn down the guitar's volume to tame the overdrive). As for the amp's EQ, I'd probably start by backing off the treble a bit, and experiment with the bass and mids to see how it sounds - I'm afraid it's hard to be specific without knowing the amp myself! Hope that's of some help - let us know how you get on! *well, probably P-90s when they recorded Paranoid, but those sound more like humbuckers than Fender-style single coils!