gush
Where is that speedo pic
Outlets in the ceiling work well for me!
Safety…And Next?
- Thread starter László
- Start date
It's concrete, but for both noise and performance I'm much better off plugging into the P-1800-PFR that's right next to a wall outlet. All the amps and the pedalboard are plugged into it. So those wouldn't be useful.
It's pretty simple:
Pedals have little amplifiers inside, mostly op-amps. If there's noise from the electrical power - which is bad enough, since it affects the signal in the pedal - as you increase the gain and output level on the pedal, you're amplifying this undesirable noise along with the signal.
Multiply this noise by the number of pedals on your pedalboard, and you can have a noisy mess that reduces clarity, forces you to use unnatural sounding noise gates (I've yet to find a noise gate on anything less than a good recording console that's worth a damn), and then your amplifier further amplifies the noise!
Noise is bled into pedals from AC line noise, from DC noise in outlets shared with other pedals, etc, etc.
The solution is a transformer, like traditional condenser microphones, good audio gear, etc., use to isolate the power inside the device from any noise coming into the device (AC or DC),
With the better-designed PSUs, it means the power supply, and therefore the pedals, are decoupled from noise coming in from the wall's AC outlet. That means power is taken in, but any noise in the power line isn't. No line noise is a good thing!
But wait, there's more!
Using an isolated PSU (power supply unit), the electrical power for each pedal is not only isolated from wall AC, it's also separated and isolated from the other pedals, which cuts down further on noise.
If you don't have an isolated power supply, one bad pedal can bleed power line and other noise into all the pedals on your board. Remember, pedals are pretty inexpensive little audio devices, and their components are rarely the best on the market.
Keeping every outlet fully isolated from the other outlets prevents this.
Another benefit of an isolated PSU is that each DC port can deliver its rated voltage draw without being affected by the current draw from other pedals, so the pedals aren't starved for power, and they work to their design spec. In a non-isolated power supply, the draw from one pedal can interfere with the draw from another pedal. Bottom line, you can power your pedals properly.
Since isolated power supplies also use a transformer, the pedals are getting the same kind of power they'd get if every pedal had its own power supply.
So that's what I mean by "isolated outlets."
One last note: There are ways of electrically isolating power that don't use traditional wound transformers; the Neumann TLM ('transformerless microphone) series are an example of devices using a different method of obtaining isolation.
However my experience is with with PSUs that use transformers.
Side tidbit:
I power my recording gear using a balanced 1.5 KvA line converter with a built in isolation transformer, and it, too, has electrically isolated AC outlets, analog from digital are separated. Balanced AC works kinda like a humbucker pickup or balanced audio line works, where noise is cancelled. Coupled with the isolation transformer, my studio tech measured about a -10dB reduction in the noise floor of my studio using an oscilloscope.
That's pretty significant if you do audio for a living and expect it to be broadcast on TV or in film.
So that gives you some idea of the potential of correctly treated and isolated power supplies. The only drawback is that my studio transformer was pretty expensive. This is the unit I use:
Equitech Model 1.5R Balanced Power System
Balanced Power Conditioner with Equitech Transformer and 12 Outlets
www.sweetwater.com
The good news is that my noise floor is absolutely inaudible, even if the speakers are turned up to insane, deafening levels.
I have to pay attention to this stuff. YMMV of course
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deathworlder
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Line and neutral are de-coupled?It's pretty simple:
Pedals have little amplifiers inside, mostly op-amps. If there's noise from the electrical power - which is bad enough, since it affects the signal in the pedal - as you increase the gain and output level on the pedal, you're amplifying this undesirable noise along with the signal.
Multiply this noise by the number of pedals on your pedalboard, and you can have a noisy mess that reduces clarity, forces you to use unnatural sounding noise gates (I've yet to find a noise gate on anything less than a good recording console that's worth a damn), and then your amplifier further amplifies the noise!
Noise is bled into pedals from AC line noise, from DC noise in outlets shared with other pedals, etc, etc.
The solution is a transformer, like traditional condenser microphones, good audio gear, etc., use to isolate the power inside the device from any noise coming into the device (AC or DC),
With the better-designed PSUs, it means the power supply, and therefore the pedals, are decoupled from noise coming in from the wall's AC outlet. That means power is taken in, but any noise in the power line isn't. No line noise is a good thing!
But wait, there's more!
Using an isolated PSU (power supply unit), the electrical power for each pedal is not only isolated from wall AC, it's also separated and isolated from the other pedals, which cuts down further on noise.
If you don't have an isolated power supply, one bad pedal can bleed power line and other noise into all the pedals on your board. Remember, pedals are pretty inexpensive little audio devices, and their components are rarely the best on the market.
Keeping every outlet fully isolated from the other outlets prevents this.
Another benefit of an isolated PSU is that each DC port can deliver its rated voltage draw without being affected by the current draw from other pedals, so the pedals aren't starved for power, and they work to their design spec. In a non-isolated power supply, the draw from one pedal can interfere with the draw from another pedal. Bottom line, you can power your pedals properly.
Since isolated power supplies also use a transformer, the pedals are getting the same kind of power they'd get if every pedal had its own power supply.
So that's what I mean by "isolated outlets."
One last note: There are ways of electrically isolating power that don't use traditional wound transformers; the Neumann TLM ('transformerless microphone) series are an example of devices using a different method of obtaining isolation.
However my experience is with with PSUs that use transformers.
Side tidbit:
I power my recording gear using a balanced 1.5 KvA line converter with a built in isolation transformer, and it, too, has electrically isolated AC outlets, analog from digital are separated. Balanced AC works kinda like a humbucker pickup or balanced audio line works, where noise is cancelled. Coupled with the isolation transformer, my studio tech measured about a -10dB reduction in the noise floor of my studio using an oscilloscope.
That's pretty significant if you do audio for a living and expect it to be broadcast on TV or in film.
So that gives you some idea of the potential of correctly treated and isolated power supplies. The only drawback is that my studio transformer was pretty expensive. This is the unit I use:
Equitech Model 1.5R Balanced Power System
Balanced Power Conditioner with Equitech Transformer and 12 Outlets
The good news is that my noise floor is absolutely inaudible, even if the speakers are turned up to insane, deafening levels.
I have to pay attention to this stuff. YMMV of course
What about ground?
Just one branch circuit supplying your studio?
I was just trying to get at the reasons "only known to the A/C gods".
I believe it's induction...The same thing that cleans your A/C noise(transformer) is the same that creates it; via induction into your ground in the branch circuit.
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The AC gods don't speak to me personally. It was just a turn of phrase to have a little fun.
If you want to know how balanced power works, here are better answers than I can give:
What Is Balanced Power? - EQUI=TECH
WHAT IS BALANCED POWER? WHAT IS BALANCED POWER? The Benefit of Balanced Power In simple terms, balanced power is a process that eliminates noise or distortion from incoming electrical current. Before the initial signal hits your devices and equipment for power, balanced power ensures you have...
equitech.com
In my current space, one circuit supplies my recording gear, another supplies my amps and pedals. That's simply based on where the plugs happen to be in my current room. There are two circuits.
If needed, the Equi=Tech has sufficient power to run the whole room, but it isn't necessary.
When I moved into my current home, I went "in the box" for much of my recording stuff, and didn't need a custom setup. I also didn't want to drop as much coin as I did before, so I bought this Equi=Tech box.
However, I powered my entire previous studio with a balanced power supply system that was custom made - including tape machines, a 60-input console, all of my analog gear - I had a lot of it - and my amps. All the wall jacks in the studio ran into this system. That wasn't necessary with my current setup with most of the 'gear' in the computer.
As far as the isolated outlet pedal power supplies, here's the manufacturer's page for one of the units I have; there's an earlier model I have as a spare in my storage room.
deathworlder
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I'm approaching this from a macro-view; I'm an electrician.The AC gods don't speak to me personally. It was just a turn of phrase to have a little fun.
If you want to know how balanced power works, here are better answers than I can give:
What Is Balanced Power? - EQUI=TECH
WHAT IS BALANCED POWER? WHAT IS BALANCED POWER? The Benefit of Balanced Power In simple terms, balanced power is a process that eliminates noise or distortion from incoming electrical current. Before the initial signal hits your devices and equipment for power, balanced power ensures you have...
In my current space, one circuit supplies my recording gear, another supplies my amps and pedals. That's simply based on where the plugs happen to be in my current room. There are two circuits.
If needed, the Equi=Tech has sufficient power to run the whole room, but it isn't necessary.
When I moved into my current home, I went "in the box" for much of my recording stuff, and didn't need a custom setup. I also didn't want to drop as much coin as I did before, so I bought this Equi=Tech box.
However, I powered my entire previous studio with a balanced power supply system that was custom made - including tape machines, a 60-input console, all of my analog gear - I had a lot of it - and my amps. All the wall jacks in the studio ran into this system. That wasn't necessary with my current setup with most of the 'gear' in the computer.
As far as the isolated outlet pedal power supplies, here's the manufacturer's page for one of the units I have; there's an earlier model I have as a spare in my storage room.
Out of curiosity are the two circuits on different phases? What are the 2 breaker's numbers?
Do either of those circuit supply power for lighting?
Have you had any issues with lighting noise?
I will admit, I am not well-versed in the micro-view; which you seem to be.
I'm always down for some schooling...
Here's an article I found interesting, that addresses some things in 'crossover territory'.
https://www.prosoundweb.com/dirty-ac-power-where-to-lay-the-blame-for-system-noise-problems/
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John F
Here for the party
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+1 on this
Cut a narrow long trench with a concrete saw, chip the concrete out, put a conduit and power cable in, and add an outlet box. Fill the trench with concrete and problem solved.
I have no idea!
I don't know that either!
Maybe? The electrician I hired last year to fix a few things told me whoever wired this place made a lot of screwy mistakes.
Just the standard dimmer noise with guitar pickups.
Well, I don't know a darn thing about real-deal house wiring. I've been tracking down and eliminating studio hums and buzzes for 35 years, though!
deathworlder
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Like I said, I'm still learning about 'noise' in when it comes to audio electrical.
Circling back to my original question about an "isolated outlet"...
In my world, this requires an isolatation transformer, isolated ground receptacles, dedicated circuits, utilizing a dedicated and isolated ground wire. I suspect this is what your setup accomplishes; just downstream of where am used to accomplishing it.
I'm wondering if a majority of the noise can be mitigated, in the way the household wiring is accomplished. This would allow you to plug in to whatever 'wallwart' you want; as long as it fed from the isolated system.
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sergiodeblanc
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Nobody ever looks into the mysterious death of a harmonica playerEach Time I Hear This Stuff, Or Move To A New House, I Am Reminded Of What A Good Friend Once Commented To Me. "All Of This Would Be So Much Easier If You Played Harmonica Instead Of Guitar And Drums".
alantig
Zombie Four, DFZ
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The only question I've ever heard about the mysterious death of a harmonica player was "What took so long?"
alantig
Zombie Four, DFZ
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A woman I used to date (and who was very good friends with my wife) married an electrical engineer. One day, when my wife when over to visit, he was messing around with a light switch. She asked him what he was doing, and he said, "You have to flick this switch down to turn on the hall light. It should be up, so I'm flipping it." My wife said, "Okay..." and walked to where his wife was and said, "Isn't that a three-way switch?" Her friend said, "I tried to tell him that."
Wait, you're saying that a woman who previously knew your schtick from dating her friend went out with you later, and beyond that, agreed to marry you?
Alan, you are a stud, a champion, a man among men. I salute you!
My wife's friends would have run in the other direction.
That's smart.
Before I got to the point where I've started to worry about aging and balance issues, I wasn't concerned, but seeing people I know well get hurt falling really made me think hard about this stuff.
Yes. In my old studio the isolation transformer was a 20 Amp 2 kVA Sola my tech modified (he was a EE from University of Michigan, and knew his stuff). It was upstream of the wall AC outlets. It had a grounded plug, but he also grounded the chassis to an earthed ground that was part of my star grounding system in my studio.
I don't know why it needed both an electrical ground and a separate ground wire for the metal chassis case, but he felt it mattered and reduced noise, and heck, he had an oscilloscope and I didn't!
I had several pieces of gear that needed both their grounded plugs and a chassis ground to the star grounding system. I don't know the reason why. I just know it worked. It was weird. Other gear did fine without it.
The old studio had a crap ton of hardware, including tape machines for audio and video with hardware synchronizers, the big console, and 5 tall racks of outboard gear, plus a bunch of synths, guitar amps, etc.
That iso transformer made mechanical noise and I had to soundproof the HVAC room where I had it installed. It was a gigantic PITA, but it worked!
The whole thing cost far more than the Equi=Tech unit I use now that's almost as powerful, and dead quiet. Makes no noise at all.
Probably so. To function like the little PSU's for pedalboards, it would require an isolated outlet for each pedal.
Also, wall warts often induce noise in pedals if they're close to the pedal, unless the pedal itself is well-shielded, and many aren't.
Seems it'd be less headache to just get a PSU with isolated outlets for each pedal in the case of a pedalboard. They aren't very expensive.
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deathworlder
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From what I'm understanding, AC grounding serves two purposes when it comes to audio electrical. Personal protection(legitimate ground fault current path) and shielding.Yes. In my old studio the isolation transformer was a 20 Amp 2 kVA Sola my tech modified (he was a EE from University of Michigan, and knew his stuff). It was upstream of the wall AC outlets. It had a grounded plug, but he also grounded the chassis to an earthed ground that was part of my star grounding system in my studio.
I don't know why it needed both an electrical ground and a separate ground wire for the metal chassis case, but he felt it mattered and reduced noise, and heck, he had an oscilloscope and I didn't!
I had several pieces of gear that needed both their grounded plugs and a chassis ground to the star grounding system. I don't know the reason why. I just know it worked. It was weird. Other gear did fine without it.
The old studio had a crap ton of hardware, including tape machines for audio and video with hardware synchronizers, the big console, and 5 tall racks of outboard gear, plus a bunch of synths, guitar amps, etc.
That iso transformer made mechanical noise and I had to soundproof the HVAC room where I had it installed. It was a gigantic PITA, but it worked!
The whole thing cost far more than the Equi=Tech unit I use now that's almost as powerful, and dead quiet. Makes no noise at all.
Probably so. To function like the little PSU's for pedalboards, it would require an isolated outlet for each pedal.
Also, wall warts often induce noise in pedals if they're close to the pedal, unless the pedal itself is well-shielded, and many aren't.
Seems it'd be less headache to just get a PSU with isolated outlets for each pedal in the case of a pedalboard. They aren't very expensive.
I assume the 2 grounds for your equipment that required it, were at equpotential and bonded at the panel?
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Alnus Rubra
Loving nature’s wonders
That’s sounds like the lady who went to her doctor and was told she only had six months to live.
She asked if there was anything to make her live longer.
The doctor replied that she could start a relationship with a bagpipe player.
She asks the doctor if this will make her live longer.
The doctor answers: “No, but it will seem like it”.
If memory serves, he attached a ground wire to a screw on the back or bottom panel of some gear, and that was in turn attached to a heavy grounding block, which in turn was connected to an earth ground via a very thick braided ground wire.
He said something about ground planes on some manufacturers' PCBs being poorly designed, for example on the old Akai S-900 samplers that seemed to have these grounding problems at various studios. I had several S-900s in one of my racks; back in the early '90s, the samplers maxed out at a mere 10 mb of RAM, so you needed several in order to do orchestral work. Worse still, RAM cost $1000/megabyte back then!
Whatever the reason, his grounding worked for the few pieces of gear that needed it. I miss the guy; he passed away several years ago, but did a lot of great work for me and several other film and ad composers I was friendly with.
I also kinda miss hardware. My computer software does more, and the machines are immensely more powerful than my old hardware samplers (Akai and Kurzweil), but there was something about having racks of gear, a console, and tape machines that made me feel at home!
This is the only bagpipe player joke I have ever seen or heard. Most excellent!
