A linear power booster DOES have a purpose, but it’s probably not useful in your situation.

Forget effects for a second. Let’s take a ride on the way-back machine to the early days of rock and roll when British amps like the Vox AC30 were the ultimate rock machine.

Rockers liked cranking up their AC30s to where they broke up, but those early amps tended to get “darker” as they got louder. They didn’t have a LINEAR frequency response as they got louder. This gave them a “muddy” sound in the mix, so treble boosters, in particular the Dallas Rangemaster Treble Booster, quickly became very popular. These were designed to sit right on top of the amp and stay on all the time. They would restore the tone that was lost by cranking up an AC30. Any effects would go into the Treble Booster which was always the last thing in the signal chain. Eventually AC30s started being made with a “Top Boost” circuit built-in.

Electro~Harmonix released their own Treble Booster, The Screaming Bird, which was designed to be plugged directly into the amp.

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Again, the Treble Booster was always the last thing in the signal chain because it was intended to compensate for tone loss in a cranked up tube amp.

As time moved on, amp manufacturers started to compensate for treble loss at high volumes in the amps themselves, eliminating the need for a treble boost as a fix. Some people still liked the sound of a treble boosted signal to “cut through” the mix when they were playing lead. Electro~Harmonix still makes the Screaming Bird, but now it’s a foot-switchable pedal that you can put anywhere in the signal chain. Still, the recommended place is usually at the very end, right before the amp.

But what about a LINEAR power booster? As I said, early amps did not have a linear tone response to volume. A linear response is one that looks like a straight line instead of a curve. As the volume increases ALL FREQUENCIES increase by the same amount – linearly. It’s actually more complicated because our hearing is non-linear! Our ears have a different frequency response depending on the volume, but let’s keep it simple.

Amps manufacturers had begun to fix the problem of tone loss at higher volumes, but many players liked the sound of boosted inputs with amps that didn’t have a lot of gain. Treble boosters worked but added too much treble, SOOOO that gets us to the

LINEAR POWER BOOSTER. A linear power booster boosts all frequencies equally – linearly – rather than boosting treble only. This allows players to overdrive the front end of an amp with low gain, or if they’re using a less powerful pickup like some of the early single-coils. Like with treble boosters, the first EHX linear power boosters were intended to plug directly into the amp, so there was not choice but to be the very last thing in the effects chain.

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How does that work now? Your amp simulator probably allows you to simulate a high gain amp that’s already treble boosted. If you have a low output guitar and you want to drive your distortion harder, you could put the LPB right in front of the distortion. If you’re amp simulator is simulating a low gain amp and you want to overdrive its input, you could treat that amp simulator just like an amp and put the LPB right before the amp simulator, just like it would have been when the LPB was originally designed. In any case, the amp simulator should definitely be the last thing in the chain going directly into your recording mixer from there.

Original Setup:

Guitar -> Effects -> Treble Boost (or Linear Boost) -> Amp -> Microphone -> Mixer

Modern Setup:

Guitar -> Effects -> (Optional Boost) -> Amp Simulator with simulated boost -> Mixer