Does 'Dirty Electricity' Exist?

[agedhorse]

They’ve worked 100% for us. If it’s snake oil? It has worked. And we’ve played some shady joints. No less than 2 have burnt down.

I assure you I wouldn’t plug my gorgeous Subway D800 into any old honky tonk power.

Has nothing to do with your power “conditioners”, you don’t know if you would have had failures if you hadn’t used them.

In fact, I have recommended not using them with the amps I have designed over the past 25 years or so. There are potential problems with these devices as well, especially the tap switching voltage regulators.

 

[bassguitarist85]

Dirty power to me a broad term. I keep a GFCI tester & pocket DMM in my gig bag. My Furman has a digital voltage readout. Still won't be able to detect a bootstrap ground though. I've played in enough VFW halls/dive bars with mis wired outlets, and most commonly refrigerator, freezer, and/or air conditioners on the same circuit for the outlets the band is using. Lose wires somewhere causing excessive voltage drop under load is common too. Another issue is a loose neutral which causes a huge voltage drop under load and the opposite half phase of that circuit goes higher in voltage relative to how much load is on each phase. Then of course there is simply poor, improper, or non existent earth grounding of the overall electrical system. These examples are more wiring issues not "dirty power."

Dirty power (at least to me) is referring to high total harmonic distortion beyond 5% NEC spec, and EMI/RFI conducted emissions through the mains wiring. A basic Furman has a common mode choke inside to combat conducted RFI/EMI. High THD is often a utility issue.

I have a nice Silgent digital Oscope and an AmpProbe THD meter but certainly not bringing those expensive tools to every venue.

 

[agedhorse]

Dirty power to me a broad term. I keep a GFCI tester & pocket DMM in my gig bag. My Furman has a digital voltage readout. Still won't be able to detect a bootstrap ground though. I've played in enough VFW halls/dive bars with mis wired outlets, and most commonly refrigerator, freezer, and/or air conditioners on the same circuit for the outlets the band is using. Lose wires somewhere causing excessive voltage drop under load is common too. Another issue is a loose neutral which causes a huge voltage drop under load and the opposite half phase of that circuit goes higher in voltage relative to how much load is on each phase. Then of course there is simply poor, improper, or non existent earth grounding of the overall electrical system. These examples are more wiring issues not "dirty power."

Dirty power (at least to me) is referring to high total harmonic distortion beyond 5% NEC spec, and EMI/RFI conducted emissions through the mains wiring. A basic Furman has a common mode choke inside to combat conducted RFI/EMI. High THD is often a utility issue.

I have a nice Silgent digital Oscope and an AmpProbe THD meter but certainly not bringing those expensive tools to every venue.


View attachment 7259671

Many amps already have substantial common mode chokes built into their power supplies, along with other components to address power quality.

 

[fdeck]

I once played a gig where all sorts of failures occurred. We discovered upon loading out that the provided extension cord ran to an outlet that was on a light dimmer.

The only things that still worked were the acoustic piano, my upright bass, and the vocal mic running through my bass amp into one of the PA speakers.

 

[agedhorse]

I once played a gig where all sorts of failures occurred. We discovered upon loading out that the provided extension cord ran to an outlet that was on a light dimmer.

The only things that still worked were the acoustic piano, my upright bass, and the vocal mic running through my bass amp into one of the PA speakers.

I had this happen once in a large theatre, the supplied power package was sourced from 3 x 50A non-dims on 3 phase legs, that were fed from dimmers all the way up. There was a noise present because even at “100%” there is still thyractor switching taking place over a very small portion of the wave form.

 

[Hurricane Jimmie]

To OP, yes, dirty nasty power exists. Never trust a venue. Make sure you have a Power conditioner as 1st line of defense and a Furman surge protector as a 2nd line of defense. It does not seem a lot when you sit down and figure what you have invested in equipment.

Some here will tell you I am silly. Not an issue in 6+ years. No noise, no blown equipment. Best offense is a good defense.

Thanks!
I've got both Furman's and will be bringing them the next time we play there. I'll also shift some of the equipment to the other side of the stage, so there's not as much going through my extension cord. I'll also upgrade my extension cord.
I'm willing to try all variables until it doesn't happen anymore.

One thing I won't do is make this an issue with the owner. They'd be doing fine w/o bands, so we don't want to alienate a venue that supports live music.

 

[agedhorse]

Thanks!
I've got both Furman's and will be bringing them the next time we play there. I'll also shift some of the equipment to the other side of the stage, so there's not as much going through my extension cord. I'll also upgrade my extension cord.
I'm willing to try all variables until it doesn't happen anymore.

One thing I won't do is make this an issue with the owner. They'd be doing fine w/o bands, so we don't want to alienate a venue that supports live music.

And THIS is what drives the marketplace (dealers and distributors as well as governments) to require that amps have safety certifications... because it's clear that users will compromise or ignore some of the most basic safety items in order to play music. Conscientious manufacturers will do what they can to minimize hazards beyond their control, but that doesn't mean all manufacturers.

If the venue is missing a safety ground, or has a bootlegged (illegal) ground, none of your proposed solutions are safe and probably not effective either. Without testing and some knowledge, you have NO IDEA what the real issue is, or if it presents a hidden hazard to you OR YOUR BANDMATES.