Haywire Custom Guitars-Active Pickups
An Active Pickup Is One That Uses Electronics To Improve The Sound
Electronics also enhance its operation and lower the magnetic requirements. There are a variety of ways to "Activate" a pickup. A simple "buffer" pre-amp will do the trick, but it will also amplify the hum and buzz the pickup produces. Just because a pickup is "active" doesn't guarantee you'll get great results just a strong ,clean and quiet signal.
EMG pickups utilize an internal pre-amp (inside the pickup), which not only makes the pickup louder, it also reduces the noise! EMG active pickups have higher output levels than traditional passive pickups. Using an internal pre-amp is the most efficient way to create an active pickup. All the coil connections are shielded, the pre-amp is shielded, and the output of the pickup cable is low-impedance, which makes it less susceptible to noise. Also, it avoids a spider web of wires and possible loose connections in your guitar and the installation is simple. All the benefits with none of the hassle.
If you find that the output level of your EMG pickup is too hot to get clean tones, the easiest fix is to reduce the gain on your amp (if it has pre-amp/master volume controls). If that doesn't do it for you, then try turning down the volume control on your guitar.
Unlike a traditional passive volume/tone system, the low-impedance EMG system lets you turn down the volume with very little effect on the tone, so you won't sound muffled when you back off the volume knob. This is much like the Haywire Treble Bleed Option for passive style pickus.
All active guitar and bass pickups we make require a battery. The EMG Select models are passive and don't need one. The active pre-amp, located in the pickup housing, is powered by a 9 volt battery. EMG active pickups and EQs are powered by a standard, rectangular 9 volt (IEC 6LR61/NEDA 1604A) battery. We recommend normal alkaline batteries (Eveready or Duracell, for example) for best results. These are the same batteries that you would use in an effects box or wireless unit and are widely available. We do not recommend the use of rechargeable batteries in EMG systems. Although they are compatible electrically, typically you must fully discharge these batteries to preserve long life, which can be problematic in normal usage.
All pickups and EQ units can run off a single battery with no problems. Since the current drain on all EMG products is very low, you should still get reasonable battery life with any combination of circuits.
You can use multiple batteries If you've got room for multiple batteries in your guitar, you can use two batteries wired in series to power your onboard circuitry at 18 volts. The output level will not appreciably increase, but you'll have increased headroom and crisper transients. This is especially useful for percussive/slap bass styles where you can generate enormous instantaneous power levels across the entire frequency spectrum.
You can also wire two batteries in parallel to provide a regular 9 volt supply but with much longer lifespan between battery changes.
Although most of EMG products are rated for 27 volts, we recommend a maximum of 18 volts. The additional benefits of 27 vs. 18 volts are negligible.
All EMG pickups and EQ systems are designed for extremely low current drain. In addition, the pickup jack included with all models has a switch that disconnects the battery when the guitar is not plugged in. To maximize battery life, you should always unplug your guitar when it's not in use.
Generally, each pickup requires about 80 microamps (uA), except for the Vintage Series pickups which require 220 uA each. EMG active EQ circuit requirements vary widely but are higher than pickups.
For your reference, a standard 9 volt alkaline battery provides 580 milliAmpHours (mAh) of power. That means that it will provide 580 milliAmps for 1 hour or 1 milliamp for 580 hours. There are 1000 uA per mA. You can figure the approximate battery life of any setup by adding up the individual power requirements, then dividing 580,000 by this total. Here's an example:
1 - EMG-81 = 80 uA
2 - EMG-SV = 220 uA*2 = 440 uA
1 - EXG = 410 uA
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Total required = 930 uA
Total life = 580,000 uAh/930 uA = 623 hours
If you left your guitar plugged in day and night, the battery should still last a month. Under normal playing conditions, you would probably be looking at changing the battery twice a year. Of course, you should treat these numbers conservatively and not try to drain every last uA out!
Because EMG pickups are designed from the ground up to operate as active pickups, they're not very functional when deprived of power. As the battery weakens over time, the output level will reduce and become more distorted. When you hear that happening, it's time to change the battery.
Below a certain voltage, the onboard active circuitry will stop working. At that point, you will hear little or no output from the guitar.
Remember: Unplug when using active pickups and guitar is not in use to prevent power loss from battery.