D. High-Gain Amps

I. Park 75

This amp delivers a classic Marshall tone. By itself, it won't get you to high-gain territory; you'll need to boost the signal (such as with an overdrive pedal, distortion effect, or simple boosted EQ) heavily to get a saturated distortion from it. I don't recommend doing that - if you want more gain but a similar tone, try the JCM-800 model instead. I like this amp for medium gain tones (AC/DC), or if I want a Marshall tone but am using a distortion pedal/effect for my main source of distortion (Satriani). Compared to the JCM-800, it has a little less distortion available but it seems to be more reactive to picking dynamics. It gives you that clean-yet-distorted crunch feel.

I like to lower the amp's Bias (and Bias X which basically "locks in" my low Bias setting). This seems to make the amp sound more like a Marshall to me - a little more nasal sounding and you can get power amp distortion without it getting too gritty or splatty. I drop it between 0 and 20%. It also allows you to dial in a bit more distortion when you want to.

This amp model seems to be one of the ones that sounds better when you crank the power section. If I'm trying to make the model distort, I'll turn Master Volume up between 85-100%, then use the Drive knob to dial in the amount of distortion. For some reason, the power section responds very "poorly" when you turn up the Presence knob on the amp. I set low, often all the way to 0%. I also keep the Bass fairly low, to keep the power amp from distorting in a muddy fashion.

If I want it to stay clean, I turn down Drive first and if I need to go cleaner also Master Volume, but I generally try to keep the Master Volume higher than 50% and turn down Drive more. The power section gets you the Marshall tone. Also, the Bias setting is more responsive the higher you set Master Volume. But keep Drive above around 5-10%. Something weird happens to the tone if you go lower.

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II. Plexi Bright

This amp also delivers a classic Marshall tone. This model is VERY accurate. Comparing it to recordings that used this amp, it sounds almost identical. By itself, it won't get you to high-gain territory; you'll need to boost the signal (such as with an overdrive pedal, distortion effect, or simple boosted EQ) to get a saturated distortion from it, but that's not where it excels anyway. It's best for a clean-yet-distorted tone, in the vein of Randy Rhodes or early Eddie Van Halen. Compared to the JCM-800, it has less distortion available but it seems to be more reactive to picking dynamics and has a much more defined midrange.

The distortion is coming from the power section, so Bias and your EQ settings heavily affect the tone. I like to crank up presence, which gives it that real crunchy feel. Boosting treble too high makes it a little nasty. And boosting mids makes it a little too smooth for my tastes. I generally set mids and highs around the same spot, and boost presence as much or more than that. And turning up Drive all the way makes it too compressed. For the EVH tone, I like to crank the Bias.

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iii. JCM-800

This amp model sounds very similar to the Park 75, but more compressed and with much more drive. Without tweaking, it doesn't sound overly Marshally; but we can get it there. Tweaked properly, it can deliver great 80's metal tones. I hesitate to call it high gain. Although it can be dialed in to produce modern metal tones, I prefer to use other amp models to do so; however, I do use it for my Megadeth patches. My favorite patches with this are for a modern Satriani tone.

Like the Park, I like to turn down the Bias and Bias X. This gives you a more natural power amp distortion and a more nasal tone.

My prefered distortion from the amp is the power amp distortion. I particularly like the sound with the Master Volume set between 65-75%. Anything more is a little too extreme; anything less just doesn't get there. I find the sweet spot, then I tweak Drive to get the exact amount of distortion/saturation I want. But don't go too high with Drive, or you'll end up mixing a heavily distorted pre-amp section with a heavily distorted power amp section, and it can sound nasty. If you need more distortion with Drive up to 40-50%, I recommend putting a boost pedal in front the amp. This will at least tweak the pre-amp distortion, so it "plays nice" with the power amp distortion.

Note that when you have a saturated distortion using the power amp section, the nature of the distortion will respond to the pre-amp EQ settings. Turning up the Bass will make the distortion muddier. Cranking the Presence will make it splatty. I like to keep those knobs conservative and cranking Mids and/or Treble. I'll often turn Bass down to like 20% and Presence to 50%, while maxing out Mids and putting Treble between 70 and 90%.

If that leaves you with an unsavory frequency response to the tone, use EQ effects after the amp to boost the bass or presence, etc.

That said, don't try to make this amp something it isn't. Where this amp excels, is that rumbly, near-muddy Marshall distortion. While I generally prefer a smooth, tight low-end to my distortion, I found I wasn't impressed with the results when dialing in this amp like that. Other models simply do it better. My favorite tones from this model involve turning up the bass and not using so much gain as to make it super-saturated. I keep it percussive and buzzy, like a crunch tone from hell.

For distortion, sometimes I'll go the opposite route and turn the Master Volume down to about 35% and crank up the Drive knob. This creates a smoother distortion, but I find it has less character. I recommend using a distortion effect or EQ in front the amp, and tweaking it heavily to find your tone when dialing in the amp this way.

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