In one of previous podcasts we talked about when to use your pedals at 18 volts. Since this topic is a little more tech oriented I asked our resident pedal engineer/ guru/ wizard/ Jake Steffes to explain it a little more in depth. With out further ado – Jake!! :
“In the podcast we talked about when to use your pedals at 18 Volts. In an analog pedal, that means that your guitar signal is going to swing above and below a reference voltage, which is usually half of your power supply voltage (4.5V for a 9V supply, and 9V for an 18V supply) like Travis brought up. This means that your guitar signal level can swing up from 4.5V to 9V, and down from 4.5V to 0V and not clip any op amps or transistors with a 9V supply (for the most part). With an 18V supply, your reference voltage is at 9V, and your signal can swing from this 9V up to 18V, or down to 0V without clipping any active circuitry (op amps, transistors). If you do your math, that means that an 18V supply essentially allows for larger signals to pass without being clipped.
In pedals with diode clipping, this won’t affect very much; the diodes are going to clip as usual regardless of supply voltage. In pedals with transistor clipping (for example, an overdrive that used JFETs for clipping), the supply voltage will directly affect the character of the clipping. With a higher supply voltage, less clipping will occur because the JFET requires larger signals to clip than with the smaller supply.
In digital pedals, a voltage regulator (a device that takes an input voltage and outputs a lower, regulated voltage) is used to power the digital electronics (like the analog to digital converters that transmit your guitar signal to digital processors). Typically, these regulators will take a 9V input and convert it to a 3.3V or 5V supply. By increasing the 9V supply to an 18V supply, you’ve done nothing to increase headroom in the digital circuitry.”
If you guys have any further questions about using your pedals at 18 Volts – don’t hesitate to give us a shout at email@example.com
– Max Jeffrey/ Jake Steffes
I have the Belle and I just want to ask if its better to run it at 9v or 18v?
We recommend 9V
What about PlexiDrive Mini? Will 18V increase harmonic content or the pedals ability to cut through the mix?
I have a Voodoo Lab Pedal Power isolated power supply and a VL voltage doubler adapter to combine two 9V outlets into one 18V. The 9V outlets put out up to 9.35V, so doubled, the 18V outlet is putting out 18.7V…
Is the normal/safe for pedals that can take 18V?