Pickup Lines
Stompbox design master Dan Coggins of Lovetone, Dinosaural and ThorpyFX shares some wisdom on the fine balance between pickup level and effects pedal headroom
“Typically, a Fuzz Face-style pedal is going to react differently depending on the pickup. They tend to be sensitive”
If you’re shooting for a certain sound via an effects pedal, it’s important to consider pickup signal strength and the differences between pickup types, because this will often have a tremendous impact on the pedal’s circuit and resulting tone.
“As a rule of thumb, the difference in level between regular Strat or Tele single coils and P-90s is about 3dB,” effects guru Dan Coggins tells us. “Humbuckers tend to be the strongest, with about another 3dB difference. The more output the pickup has, the less likelihood there is the pedal will be able to cope with the dynamics. But, at the other extreme, although a lower-output pickup is going to achieve more dynamic range from an effects pedal, [the signal] will be further down towards the noise floor and, therefore, the more the noise created in the pedal is going to dominate. So, it’s all a bit of a compromise.
“The dynamic range is measured between the noise-floor limit at the bottom of the scale and the peak clipping limit at the top of the scale,” continues Dan. “Headroom is the amount of amplitude you can put through a linear audio circuit before it clips and is defined by the voltage limits in the pedal. And as most effects pedals only work on nine volts, they don’t tend to have a tremendous amount. With lower headroom you’re more likely to get clipping distortion, which may, or may not, be nice. It’s not such a big deal with something like a compressor or fuzz – effects that limit dynamics by their very nature – because you’re deliberately limiting the headroom as part of the effect.
“The action of the compressor will smooth out the level variations of different pickups, but you’ll be pumping and driving the compressor more with a higher-output pickup like a P-90 or humbucker, and with a weaker pickup you’ll have to hit the strings harder for it to compress as much. The [Dinosaural OTC-201] Opticompressor I used to make, which is what ThorpyFX’s Fat General compressor is based on, had the Axematch three-way switch that gave unity gain in the middle, and either 3dB of boost or 3dB [of cut] to help match pickup types and account for the differences.”
Certain types of effects, particularly vintage-style fuzzes, are much more sensitive than others with respect to variations in pickup signal strength.
“Typically, a Fuzz Face-style pedal is going to react quite differently depending on the type of pickup being used,” says Dan. “They tend to be very sensitive to pickup level. When you back off your guitar’s volume, you get a rapid attenuation – it becomes a very strong gain control to the Fuzz Face, because the pedal can cope better with the dynamics of the pickup. Conversely, the more you turn the volume on the guitar up towards 10, the more your pickup is obliterating the input of the Fuzz Face – the input capability, or headroom, of which is limited to less than a volt.
“When it comes to overdrive, you’re going to drive the amp harder with a louder pickup. A Strat pickup isn’t going to hit the amp as hard as a Gibson humbucker, for example. Rory Gallagher used to take his Strat and put it through a Rangemaster [booster] and drive his AC30 with it. Although it’s often referred to as a treble booster, the Rangemaster is more of a midrange booster, because the top-end and the bass drop away, and you’re left with this hump in the midrange. That’s a vintage form of overdrive that really is boosting the pickup and slamming the amp, but at the expense of the dynamics.
“If you were to use something like ThorpyFX’s Team Medic, which has got an 18-volt supply and lots of headroom, you get a really powerful clean boost and it will slam anything it’s connected to with very low noise and lots of headroom. So you could beef up a Strat or Tele pickup into humbucker territory but with the bite of a single coil.”