There are several pairs, or axes, of tonal qualities:

• Crusty vs. liquidy. Caused by eq before clipping/saturating/distorting, due to whether the high frequencies are clipped the most and thus dominate the most (giving a bell-like, liquidy, tinkly character), or whether the low frequencies dominate, giving a crusty, dry, rocky character of breakup. This is pre-distortion eq, which is emphatically *not* to be confused with eq'ing the resulting breakup tone (post-distortion eq). This principle not only applies to the preamp distortion stage, but also, please note, applies to the power-tube-and-mic'd-speaker stage, which you should think of as nothing but a large distortion box, subject to the same principle of the difference between pre-eq and post-eq.
• Hard vs. soft power tubes. The Groove Tubes' rating system formulated these concepts. The early Marshalls used EL34 power tubes, which have a soft, squashy dynamic compression. The 80s Marshalls used 6550 power tubes, which have a hard, percussive, brick-wall dynamic compression.
• Preamp vs. power tube (and speaker) saturation. No matter how good your preamp distortion voicing is, it has a different character than the complex dynamics of saturating power tubes interacting directly with a hard-driven guitar speaker.

or120 at aol.com (OR120) wrote:

>I was a Laney dealer when they were 'reintroduced' in the mid eighties. The primary reason was that I had always been a big Sabbath fan, and owned an old 60 watt plexi Laney, and 4x12 cab (I still have the cab). The press, and quotes from Iommi, which were backed up by the video he had out at the time, was that he used Laney primarily through Volume IV, and used Marshall's then, and later went to Boogie, and eventually back to Laney.

>Also (and this again is repeating what I was told by Laney and perportedly Iommi), no inline effects, just cranked, and Fane speakers, which had a boxy sound with the amps wide open. His first couple efforts used P-90's (my fave), and then some custom made pu's, I forget. I have seen pictures of Iommi w/ humbuckers, and a video of Iron Man from the early 70's had him using Orange amps (still my favorite as far as big amps). I have a really cool video of Sabbath from Paris in 1970, and Laney was the back line. This video is available from the video dealers at the guitar shows I exhibit at, man it's bad-ass, even Ozzie sounded great and they let him have center stage! :)

I promote paying attention to the principles of Amp Tone, rather than particular brands.

I'm glad you mentioned Volume IV by Black Sabbath. There is an interesting, key tone-combination there, in the song "Cornucopia". On one channel, the power-tube and speaker distortion sounds crusty, and on the other, it sounds liquidy. This are the opposite poles of the Amp Tone spectrum (I don't mean the blues vs. shred, that is, power vs. preamp, spectrum, or hard vs. soft types of power tubes). How did he do it?

To get the crusty tone, turn up the amp's Bass tone knob, and turn down the amp's Treble tone knob. To get the liquidy tone, turn down the amp's bass tone knob, and turn up the treble.

This technique also works when placing an eq stage before a preamp distortion stage. Even without an eq pedal, you can test this technique right away by using the neck pickup and turning your guitar's tone knob to minimum treble -- there, you have a crusty Sabbath tone.

Try hitting the low E string hard, then playing the thin, high E string while letting the bass string ring -- you get a ring modulator (buzzing-noise) effect.

For the buzzing noise behind the "Paranoid" lead, stand next to your amp such that your guitar picks up the 50 or 60 Hz hum of the AC power line, interfering with your solo.

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