The active pickups are hotter than passive pickups myth exploredWritten by Grant Stab
Active pickups are notorious for their hot outputs, and if there was ever a culprit for unwanted distortion, it's active pickups. Er, right...?
On forums throughout the web, and on pickup manufacturers' websites, you'll find meaningless terms such as "8 kilo-ohm!" and "hot!". This doesn't really tell us mere-mortals how powerful our pickups truly are, though, in a way that's useful to us. So forget kilo-ohms - let's talk volts*.
"Volts? Shut up, you nerd!", I hear you shout. Bear with me, it's actually pretty simple. Most guitar and bass pedals run on 9-volt batteries or power supplies, so it follows that you want your guitar signal to be less than 9 volts. Much like how you wouldn't drive a double-decker bus into your garage.
Let's take three pickups, scientifically-selected by a process of "I have them laying around". First, let's see how powerful they are on their own, then plug them into a pedal and see what happens. We'll be using something called an "oscilloscope", also known as a "sillyscope", and I'll strum as hard as I can.
These pickups are: a Seymour Duncan Little '59 in a Telecaster, a SH8b Invader in an Ibanez RG370, and an EMG SSD in a Spector Legend bass. The first two are passive, while the last one is an active pickup, custom-designed by EMG for Spector. All are in the bridge position.
So what do the pickups' outputs look like when you strum a chord straight into the sillyscope?
So the EMG is the weakest of the three. Wuuuut?! Crazy stuff. While all these pickups seem quite powerful, they're all below 9 volts.
Now let's play them into a buffer, which is probably the most simple type of pedal, and doesn't add any gain or amplify the guitar signal in any way. You'll find a buffer as the very first circuit your guitar meets in most pedals.
Oh, dear. Turns out, most 9-volt pedals actually have 6V or less of headroom, so some of these pickups are screwed from the get-go. Strum lightly, and you may get away with things. Strum hard, and you'll distort a pedal which isn't hasn't even added any gain.
What happens when you DO add gain? Let's say a mere 10dB (which should make the signal about 3.2 times stronger). Let's use a clean boost pedal.
This poor waveform didn't stand a chance. These pickups will make "clean" pedals distort, and will make dirt pedals distort at a much lower setting on their Gain knobs.
What can be done? Well, you could either use a volume pedal before any other pedals, use an 18-volt supply on pedals which allow it (always read the manual!), or you could avoid these pickups. Why don't amps have this problem? Well, because solid-state amps usually clip at about 30 volts, whereas tube amps can accept hundreds. A wee bit more than your 9-volt battery.
*It's really "Volts peak-to-peak", or Vp-p, that we're measuring, but you would have stopped reading if I tried to spring that jargon on you.