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Topic: Dirty Power and DAW |
Jon Light
From:
Saugerties, NY
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Posted 4 Jul 2017 4:51 am |
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I have spent a fair amount of time reading the forum and elsewhere on the subject of bad line power but this is a specific question about the digital realm.
I've got some new power/noise issues in my new (old) country home. I've ordered a sub-$100 conditioner that may, may not help for some low-volume noise coming from all my amplifiers, intermittently, that seems to me to possibly be motor (water pump, refrigerator) related. Sort of a sound of 'rushing' and fluttering, underneath the signal.
I don't think voltage stability is an issue.
Question:
IF the problem is indeed caused by motor-generated interference and IF a cheap power conditioner helps with this (big if -- it is a Furman that claims to be a surge suppressor AND a line filter), would I need my DAW to have this line conditioning too, or is the digital realm unaffected by line noise? Or more affected?
I'm trying to plan layout and physical location of amps, computer rig, power outlets, separate circuits, etc.
Rephrasing the basic question: is line filtering even relevant to digital recording? |
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Robert Leaman
From:
Murphy, North Carolina, USA
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Posted 5 Jul 2017 10:57 am
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The very best line conditioner is a Sola transformer. You should use the model that has harmonic filtering. I have specified this in many industrial installations where the mains are very dirty and computers need clean, regulated sine wave power. Solas run very hot since they always in saturation but you can expect less than 1% regulation where the line varies from 85 to 140 VAC. Sola transformers are not cheap but they do the job.
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Jon Light
From:
Saugerties, NY
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Posted 5 Jul 2017 1:25 pm
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| Thank you. |
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ajm
From:
Los Angeles
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Posted 6 Jul 2017 7:17 am
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The original question: "is line filtering even relevant to digital recording?"
It goes without saying that the more stable and cleaner your AC power and your general recording environment is, the better off you will be no matter what.
However, that is not what I perceive your question to be.
I'll take a stab at it and let others comment.
Assuming that the AC voltage is stable......
Dirty power in the lines or floating around in the air may affect the signals that you are trying to record (guitars, mics, etc.). So any signals that get recorded will have dirt on them.
Once it is recorded it is digitized. After that, in the digital realm, there will be no effect. The computer deals with 1's and 0's, and analog noise will have no effect.
Then, listening back to it, after it is converted back to analog, you may hear some dirt added in additionally at that stage.
OK, fire away. |
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Jack Stoner
From:
Kansas City, MO
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Posted 6 Jul 2017 9:20 am
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To add, from your original post it would appear the DAW (PC) needs the power filtering too.
If the line is as dirty as you state, I don't think a $100 unit is going to do the job. It will required "major" line filtering/conditioning. But, see what the $100 unit does, if not return it and dig deeper into the pocketbook for a much better unit.
I have my DAW (PC) and my recording interface unit (MOTU 896MK3 Hybrid) on a UPS system which also has surge protection and some (minimal) line filtering (normal non-battery operation). |
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Jon Light
From:
Saugerties, NY
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Posted 6 Jul 2017 9:41 am
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Jack--I was just composing my response to ajm when you posted. I've pasted it below. Thank you. How dirty is the line? That is either the hundred or thousand dollar question.
----------------------------------------
ajm's reading of my post is pretty much proper.
IF an inexpensive filter succeeds in cleaning up stuff like motor noise in the line, then IF I don't run the computer through the same filter (in order to spread the load over a couple of circuits), will the (possible) motor noises that the filter is cleaning up in the guitar amp have negative affect on the unfiltered computer and its digital recording.
This is all assuming that voltage fluctuation is not an issue. I've seen no obvious evidence of that (no lights flickering, no digital stuff getting weird).
Of course, if the filtering does work on the guitar/amp end of things and if there is a problem on the computer end of things, I suppose that the purchase of another $80 conditioner for the computer circuit is a no brainer.
A lot of ifs. Waiting for the order to arrive. |
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Godfrey Arthur
From:
3rd Rock
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Posted 15 Jul 2017 5:04 am
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| Jon Light wrote: |
| is line filtering even relevant to digital recording? |
I would venture to say that if you use a laptop which has low voltage filtered/regulated power/autovolt power supplies, the digital operation of your DAW would not likely be affected.
The distortion would happen in or after the converters I surmise the DAC (digital to analog converters)
But let me back up and say this; using a cheap wall wart to power an outboard drive to play back movies into a flat screen, I did notice that using a regulated pro video 12 volt power supply to the drive resulted in a clear picture even if the screen was plugged into a wall outlet AC. The drive "performed" better to my surprise. So go figure.
But you can't interpret digital as you're not a robot and analog audio and video is what you monitor with being a human. Your music out of speakers, your computer screen are not digital software, it is all analog. That is where the noise and signal distortion is apparent and if your line is dirty, you have a smart meter installed by your government on your home (opt out) you won't get a good representation in the audio and video realm because of polluted power.
Besides spurious frequencies introduced into your house current lines and who knows what else as AC can be used to send audio as these digital meters are designed to send reading signals to the meter reader without having to view your meter, a smart meter did this:
To be safe, filter and balance your power lines going to the studio for all your audio/video gear. Don't just think your AC coming off the pole or if you have buried lines is going to be clean and running at the voltages your equipment needs.
These days power companies are experimenting with running odd voltages and don't really care if your equipment is needing a specific voltage.
Power companies were supposed to guarantee stable 60hz but I think they are varying that even these days. If the Hz is not exact your analog equipment will be affected, you will hear different audio if your Hz is below or above 60hz. Some companies make frequency converters. We use them in Hammond organs to keep the Hz at 60hz because that is how the organ maintains its pitch for most countries running 60hz AC.
Voltage regulators are good at keeping voltage stable BUT they present noise in audio equipment!
What you would need if you want to do it properly is after any automatic voltage regulator, an Isolation Transformer This then filters much noise and improves things like video resolution as well as audio on the analog side, after the digital converters, your amps and speakers as that is what is your connection with the digital world.
A cheap line conditioner depending on the quality will not always work. Many of them are a big metal box with just a capacitor inside which takes away clicks and pops. Be alert though that spike/surge filters can be dangerous in a studio as fires have resulted to studios from these power strips with spike/surge suppressor filters. The circuit catches fire in those.
An isolation transformer there are cheap ones but the expensive ones are the ones that do the job especially in a studio setting.
Another thing to look at is having a dedicated line away from your home circuits that run air conditioners, motors, refrigerators, a separate breaker box for the studio alone with "clean" AC lines as well as a "dirty" AC line breaker box. You want to plug into your "clean" AC lines isolated from the dirty side with the motors and preferably an Isolation Transformer, and then run lights, vacuum cleaners, fans on your dirty lines.
Note: if you use compact fluorescent lights, be aware that those lights were back door engineered to send signals to your computer so how they are adding pollution to your audio. It has all to do with smart meters and these "new" lights. Even LEDS, I wonder about how those are working behind the scenes as an infra red led in your TV remote can send and receive signals now don't they..
Use good grade AC wire and good outlets for studio purposes. Hospital grade outlets are something to consider.
Most pro studios go to this extent to quiet the studio.
Another thing to consider, when the studio was built to install a Faraday cage, lining the walls, ceilings, floors with a shielding material, even heavy duty aluminum foil if not thin aluminum plate for the lower cost vs copper foil, and there are other materials that get real expensive for shielding, throughout before your acoustic wall treatment all electrically tied to each other and then tied to earth ground with a grounding rod buried into the earth about an 8 foot length.
Home Depot sells grounding rods that are copper tipped.. looks like a long spear.
This device is an isolation transformer seen a lot in pro audio live situations.
Here is a wall cabinet from Equi=tech a company that provides line filtering to studios, mastering suites:
They also make isolation transformers:
Here is their smaller capacity rack mount isolation transformer Son of Q:
The next best thing would be to generate your own power with your own gen set, not connected to the city grid which is why most pro concerts use gen sets to run their audio and lights not just for the clean stable power but for a power outage killing the concert.
These gen sets are so quiet you can't even tell they are running.
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 15 Jul 2017 6:55 am
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| Quote: |
| Rephrasing the basic question: is line filtering even relevant to digital recording? |
Yes, definitely. Noise transmitted via, and/or radiating from, mains cables, can interfere with all electronic equipment - especially digital.
Saturation transformers have been mentioned already, and when I experience real problems with interference and instability with electronic equipment - analogue and digital - I feed it (all) via a saturation transformer. Real saturation transformers both stabilize the voltage within a wide margin, and cleans out / chokes off all frequencies above the mains frequency they are built for.
Saturation transformers are heavy and tend to get hot as they convert noise into magnetic energy, and should not be placed in a studio - or anywhere near microphones - since they give off audible hum that vary in intensity with the amount of noise and overvoltage they filter out.
I often complement such heavy mains filtering by organizing mains and signal cables to avoid cross-interference, and clamp ferrite beads/chokes on longer analogue and digital signal cables that aren't already choked off properly. |
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William Johnson
From:
Statesboro, Georgia, USA
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Posted 18 Aug 2017 1:49 pm Recording: Clean power and Technical Grounding
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Recording: Clean power and Technical Grounding
Jumping in ... I've built several project and mid level commercial studios. In most cases, I learned that typical electrical power distribution and grounding techniques using minimal Code requirements, is not adequate. IF you demand your 'top drawer' expensive mics, pres, FX, speaker monitors, etc. to meet your expectations (and manufacturer's specs), a proper technical electrical power and grounding system must be designed and installed!
If not, the 'noise floor' will likely be too high for you to properly hear the details of the human voice, reverb tails fading out with sparkle, acoustic string harmonics, etc. You know what I am trying to explain in words ... the subtle sounds of music. Of course having a save recording environment.
I will gladly start a thread reviewing what I have learned over the years. The Beatles severely influenced me and off I went ... learning to play guitar, forming bands, recording, doing live sound, just digging the 'musicians' life-style! For 20 years I had a 'day-time' job as electrical engineer for a large USA manufacturing company, but I kept evolved in my passion for music and the technology to improve its presentation to us.
Anyways ... enough rattling on, give me some feedback on this topic and I'll start a thread on technical power as related to recording studios, multi-media and live sound.
I look forward learning form everyone.
Billy
_________________
William Johnson (Billy)
Statesboro, GA
Sho Bud Student / Emmons DB E9
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Jon Light
From:
Saugerties, NY
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Posted 20 Aug 2017 4:33 am
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Knowledge is good. Information is good.
If you want to publish stuff for the general good, go for it. Here or in its own thread....no matter.
It will not particularly interest me or pertain to my needs. I am not building a studio and I am not a student of the subject. Just laying some tracks remotely. |
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John McClung
From:
Olympia WA, USA
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Posted 20 Aug 2017 9:15 pm
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Jon, I was having an intermittent humming distortion noise problem in an old house from the 50's. Tore my hair out trying to figure out where the noise was coming from, all AC in the home was 2-prong ungrounded. Stumbled on the solution one happy day: my Macbook laptop next to my steel was the cause. Moved it away a couple of feet, problem gone. Hope it's that simple for you!
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▪️ If you want to have an ongoing discussion, please email me, don't use the Forum messaging which I detest! steelguitarlessons@earthlink.net |
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