duhvoodooman
June 30th, 2008, 09:22 AM
This subject has come up a couple of times in conjunction with the BYOC "Extra Special Vintage" Tone Bender fuzz pedal kit that I posted about HERE (http://www.thefret.net/showthread.php?t=7573). Some older effects pedals, notably fuzz pedals based upon PNP germanium transistors (and clones thereof), are wired for positive ground, due to the current flow requirement of that transistor type. As I mentioned in the linked thread, you can still use a standard center-negative AC adapter (a.k.a. "wall wart") to power these pedals, but you can't daisy-chain them with the far more common negative-ground pedals on a single adapter. Doing so shorts out the adapter itself and may burn it out.
The very reasonable question has come up about using one of THESE (http://www.musiciansfriend.com/product/Godlyke-Power-All-Cable-Red-R-Right-Angle-Reverse-Polarity-Cable?sku=150299) polarity adapters to connect such a pedal to a multi-pedal daisy chain. Unfortunately, that's NOT what these polarity adapters are for! Their purpose is to allow the connection of a device with an AC power adapter jack that is wired for a positive tip and negative barrel to a negative tip/positive barrel AC adapter, which is the standard type used to power almost all effects pedals. The description from the MF product page is quite clear on the adapter's function:
"The Cable-Red/R allows you to power effect units that have reverse polarity barrel connectors (tip positive/barrel negative). The Cable-Red/R features a tip positive, male barrel connector that is spring-loaded to prevent disconnection."However, though its AC adapter jack is wired in reverse, the device itself must still be negative ground!! So this polarity adapter will not work for positive ground pedals. I asked exactly this question of some of the "pedal gurus" over at the BYOC user forums some months back, and they were very clear in their response: nice try, but WON'T WORK!!
The very reasonable question has come up about using one of THESE (http://www.musiciansfriend.com/product/Godlyke-Power-All-Cable-Red-R-Right-Angle-Reverse-Polarity-Cable?sku=150299) polarity adapters to connect such a pedal to a multi-pedal daisy chain. Unfortunately, that's NOT what these polarity adapters are for! Their purpose is to allow the connection of a device with an AC power adapter jack that is wired for a positive tip and negative barrel to a negative tip/positive barrel AC adapter, which is the standard type used to power almost all effects pedals. The description from the MF product page is quite clear on the adapter's function:
"The Cable-Red/R allows you to power effect units that have reverse polarity barrel connectors (tip positive/barrel negative). The Cable-Red/R features a tip positive, male barrel connector that is spring-loaded to prevent disconnection."However, though its AC adapter jack is wired in reverse, the device itself must still be negative ground!! So this polarity adapter will not work for positive ground pedals. I asked exactly this question of some of the "pedal gurus" over at the BYOC user forums some months back, and they were very clear in their response: nice try, but WON'T WORK!!