I took one of the troublesome SBP-1 pedals to my gig the other night, plugged it in to our desk via the XLR and it made the same massive noise and hum. Flicked the ground switch and it got worse, just like here at home.
The retailer send me a third pedal, it arrived Tuesday and it had the exact same hum problem again. I also noticed that I would get a little zap from my guitar cord every now and then when plugging and unplugging when connected to an amp and a mixer or interface.
Today I decided to get the multimeter out and see if the grounds were connected between the 1/4" and XLR. I found the XLR has been mis-wired on all 3 new pedals sent to me. Pins 1 and 2 are reversed compared to my old pedal and other standard DI boxes I have. The reversed wiring puts the ground connection onto the signal + pin and vice versa. Hence the hum. So there must be a batch issue.
Here's a photo where I've circled the ground pin on the new pedal (left), and my old pedal (right). At least I know what it is now. Hopefully Warwick/Sadowsky can remedy as I'd like to replace my scratchy old SBP-1.
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Mark….please email your findings to [email protected]
at one of the several Halloween parties and/or gigs over the last couple weeks. Haha