How to Choose the Best Boost Pedal to Suit Your Electric Guitar Gear
Author: Siraj Jardine
Date Posted:21 May 2020
This blog post will cover the topic of boost pedals. It will discuss their history, as well as some of the different types of boost pedal circuits on the market.
A Brief History of Boost
Boost pedals are one of the first innovations in the neverending pursuit of tone. It was a way of increasing the signal amplitude after the pickups but before the amp (that's why these are sometimes called pre-amp boost pedals, but that's a separate debate). A key concept to understand before we dive into boost pedals is amp headroom. Headroom is the threshold below which your guitar amp will produce a clean tone. Anything above the headroom threshold has an overdriven or distorted sound, depending on the extent to which you push the amp. Generally speaking, a higher amp wattage means more headroom. The invention of humbucker pickups, with higher output than their single-coil counterparts, helped to drive amps beyond their headroom threshold and into overdrive. When musicians discovered how good their overdriven amplifiers sounded, they wanted more, hence the use of boost pedals to increase the signal from their pickups even further before hitting the amp.
One of the first boost pedals was the Dallas Rangemaster Treble Booster. This was invented in the context of dark-toned amps with an underemphasised treble output. The Rangemaster breathed some life into these dark amps by boosting the mids and high-mids for some interesting harmonics (think Brian May). After the Rangemaster, artists used the Echoplex Tape Echo for a boost by turning down the delay and cranking up the volume on the pedal. Next came plug-in treble boosters that plugged directly into the guitar's input jack with a level control knob, like the Electro-Harmonix LPB1. The LPB1 was the inspiration behind many modern guitar boost pedals on the market today.
When it comes to pedal order, remember: Boost before overdrive = more saturation; overdrive before boost = louder. This is also true in relation to headroom: No headroom left in your amp + boost = more saturation; lots of headroom left in your amp + boost = louder.
Types of Boost Circuits
This could get a bit technical, but we'll try to keep it as accessible as possible. The following list shows the most common types of boost pedal circuits, along with some examples.
- Non-inverting Op-Amp: MXR Micro Amp - boosts all frequencies to a similar extent
- Inverting Op-Amp: Xotic Effects RC Booster - slight attenuation of low frequencies, but this might not be detectable since guitar amps don't usually reproduce sounds below 80 Hz very well. There's also a subtle mid-hump, much less pronounced than a tube-screamer.
- MOS-FET: Z Vex Super Hard On - quite an even boost in frequency, and will typically have a crackly volume/gain knob (which is unavoidable). This circuit tends to be a little louder than the previous 2 op-amp-style circuits.
- JFET: Xotic Effects EP Booster - this type of pedal is usually referred to as a pre-amp, but this is not a standardised term. These pedals typically sound like spluttery fuzz pedals when used with high-output pickups.
- Mu-amp FET / Push-Pull JFET: Analog Man Bad Bob - this circuit has a fairly obvious low-frequency cut (high pass), and you might have to roll back your volume pot to get a good sound. Single-coils sound really good with this. You'll get that spluttery fuzz pedal sound with a higher-output pickup.
- Top Boost: Dallas Rangemaster Treble Booster - you'll notice the cut in low and low-mid frequencies with this style of circuit. This can help you to tighten-up a muddy low-end.
For a thorough explanation of these types of boost pedal circuits, including some diagrams, check out this video:
Versatile Option from NUX Available at Artist Guitars
If you'd like a pedal that can do more than one of these, you should check out the Boost Core Deluxe pedal. The NUX Boost Core Deluxe integrates two circuit forms, simulating the Xotic RC Booster and the slightly dirtier Xotic AC Booster. It also adds a circuit similar to the Treble Booster before these two Xotic-style circuits for added versatility. These 3 circuits are controlled with a 3-way toggle switch.
The Clean mode (RC Boost) retains a very transparent boost signal, just like the original RC. This pushes the first-stage tube of a vacuum tube amplifier while allowing you to use the EQ to tweak the sound.
Note: Maximum amplification 20dB
The Dirt mode (AC Boost) uses asymmetric diodes for clipping, to produce an overdrive similar to vacuum tube amplifiers. This higher-gain setting uses an RC-style filter to remove some harshness in the treble frequencies. The Baxandall-style EQ controls enable you to further shape the tone.
Note: Maximum amplification 35dB
In the Spark mode, a high-pass filter is used to simulate the frequency response of a Top Boost pedal. When used in conjunction with the AC circuit, you can obtain the classic Top Boost tone.
Note: Maximum amplification 35dB