RF Interference - what can I do?

[lovgren]

Originally Posted by James May

A point of clarification here about grounding ToneDexter. You can do it either through the XLR or the 1/4" main output. The 1/4" output is always connected to TD system ground.

If you use both outputs, the XLR ground is disconnected. In other words, plugging in the 1/4" output opens the XLR ground to avoid ground loops.

I'm wondering if terminology is getting confused. You're claiming if I use both outputs, the XLR ground is disconnected? That's not what I've experienced. I sometimes get audible RF interference (not 60hz ground hum) when I connect only the 1/4" output. But when I additionally connect the XLR to a grounded device (a powered speaker in my case) the interference disappears. So it must be using the XLR ground even with the 1/4" connected. This same result was also observed by the OP above.

I'm confused. Can you please elaborate or double-check?

[James May]

Originally Posted by lovgren

I'm wondering if terminology is getting confused. You're claiming if I use both outputs, the XLR ground is disconnected? That's not what I've experienced. I sometimes get audible RF interference (not 60hz ground hum) when I connect only the 1/4" output. But when I additionally connect the XLR to a grounded device (a powered speaker in my case) the interference disappears. So it must be using the XLR ground even with the 1/4" connected. This same result was also observed by the OP above.

I'm confused. Can you please elaborate or double-check?

Sorry for any confusion with regard to terminology. I am sure that when you insert a plug into the 1/4" output, you break the ground connection from ToneDexter's ground to the XLR output pin 1. That is our way of giving you a ground lift option without having to have a dedicated switch for it.

Your experience with RF interference changing could be caused by other factors, such as the input impedance of the XLR you're plugging into being low enough to eliminate the buzz, even if the ground isn't actually connected. It can be complicated. If you plug the 1/4" output by itself into something that actually has an earth connection (via 3 prong power cord), the buzz should go away. Let us know if that isn't happening.

[buzzardwhiskey]

Got the Strymon Ojai R30 today and sure enough, the noises are completely gone. Dead silent except for the guitar. Yay!