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Which gear needs to be plugged into isolation transformer?

Discussion in 'General Discussion' started by kmetal, Dec 6, 2019.

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    The New AT5047 Premier Studio Microphone Purity Transformed

  1. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Hey ive been thinking about deliver clean power to my rig as it approaches completion. The use of isolation transformers seems to make sense since the rig will be in a regular house, without any modifications to the existing electric service. My questions are:

    1. What pieces of gear need to be plugged into an isolation transformer?
    • Powered Studio Speakers?
    • Audio Interface/Converters?
    • The Computers?
    • Outboard pres, comps, eqs?
    • Guitar Amps?
    • Midi/DAW controllers (devices that don't pass audio)
    • USB devices like external drives?
    • Flatscreens?
    • Tape machines, record players?
    • Network switch for slave pc's?
    • Network switch for internet access?
    • Anything else?
    2. Does all equipment need to be connected to a single iso xformer?

    3. Do certain pieces need to be grouped to be plugged into the same xformer? ie, the monitors and converters.

    4. Do the iso xformers need to be all on the same circuit or outlet in the house?

    5. Are fridges, cfl light bulbs, air conditioners, other appliances a concern if on the same cricuit as the iso xformer

    6. If isolation xformers are used, does an additional iso box need to be used specifically for the usb converters? (Bozwell had linked one in another thread recently that he got good results with a laptop.)

    7. Do battery backups, rack power conditioners, rack voltage regulators, enhance, negate, make redundant, or have no effect, on the isolation xformers performance? ie is any of the other stuff useful or a waste or harmful.

    8. Are rfi, wifi, cellphone, emi, terrestrial radio, Bluetooth, interferences a concern?

    Im interested both in what's ideal, and what's the minimal requirements. I will probably wait to do critical analog to digital transfers either at the studio, or until my new place is ready with proper studio grade electrical and emi/rfi rejection.

    The rig is 5 PCs, a laptop, 1 NAS, 2 converters, an eleven rack amp sim, a midi controller, 2-3 pairs of speakers (for main and capture systems) probably a tablet for remote control, and maybe a couple outboard units. 1 pc will occasionally be connected to the internet, the nas, and laptop constantly connected. Not sure if it will be by cat6 or wifi. I also anticipate sending BT audio to bt speakers around the house via either built in BT, or a little transmitter connected to the interface, maybe both.

    Usage of system would be generally just midi composing, audio demos, and mixing for fun. Possibly some podcasts and videos, and maybe safety copies of archive stuff like tapes, vhs, vinyl. I can't imagine much paid gigs in this place, but perhaps some small editing, or mixing. Also general web browsing and streaming.

    Thanks.
     
  2. bouldersound

    bouldersound Real guitars are for old people. Well-Known Member

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    I'm not sure it's necessary unless there's a specific problem you need to address, like DC on the line or ground loop noise. But it probably wouldn't hurt. Maybe total up the amperage of all that gear and see if it's within the capability of the transformer, then give it a try.
     
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  3. Boswell

    Boswell Moderator Distinguished Member

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    In simple terms, you either need everything plugged into the output of the iso transformer or nothing. Most audio gear carries a mains earth through its input and output cabling, so if you have a mixture of interconnected things through the transformer and not through the transformer, the output ground would be connected to the input ground, negating tha isolation.

    It's worth considering a quality mains filter to reduce the effects of fridge clicks and other mains-borne interference, and even a UPS of the type that regenerates the mains sinewave. These are not cheap, but they can make quite a difference. They can act as isolation transformers as well.
     
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  4. paulears

    paulears Well-Known Member

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    I've always looked on them as problem solvers - used to solve a specific issue.

    There are a number of issues when it comes to using them in an installation. Size and cost are pretty important. High current ones can be amazingly expensive. They also have quite a lot of myths. They provide isolation - that's all. They do NOT cure waveform distortion. Most will happily pass spikes and superimposed noise unless designed with filters to remove harmonic distortion. They're good at reducing current flow in the grounds as there is no direct path. Some of your kit will already have them if they use class II operation where the power supply transformer does the same thing. Your switch mode interference causers will still do it , because they are downstream of the transformer, and if they're noisy will still contaminate everything.

    That all said, my house is 1964, with a mix of modern and original wiring, and I don't have any switch based interference in my studio that is on it's own ring circuit. In modern locations, I suspect clicks and pops are actually indications there are problems elsewhere that could be fixed. Using transformers to 'fix' the problem just leaves the real one untouched. You also need to check on the circuit protection. Using transformers can impact on how RCD devices work in some cases. Regenerative UPS driving a faulty device may well remove the protection in some circumstances as they are in a sense, a totally separate supply.
     
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  5. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    By a mains filter, are you referring to the isolation xformers that connect to the main breaker box?

    Also im still unsure of this- if i use several of the iso xformers that plug into a standard outlet, is this acceptable? Or do the equipment have to be plugged into the same iso xformer, requiring a much higher wattage/amperage unit.

    Do midi cables carry the earth ground like usb and audio does?

    And the iso xformer does nothing for emi, rfi, airborne interferences?

    My current place is from 1976. Did you use an isolated ground method on your studios circuit?

    I agree problems should be solved at the root. Im just not willing to put any work into the existing house since its a rental, and im planning on moving within the next year or two to a place i own. I just wont see a return on investment in that short of time.

    Worse comes to worse ill just live with any issues at this place, which may delay critical archiving projects.
     
  6. cyrano

    cyrano Active Member

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    This is the most important part.

    And "everything" usually means it's too expensive, unless you have a specific problem too solve. In that case you should try-before-you-buy.
     
  7. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Again, i ask does it have to be the same iso xformer, or can it be several separate xformers?
     
  8. cyrano

    cyrano Active Member

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    You can use several. Especially pleasing if you're a bit of a masochist... :rolleyes:
     
  9. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Just to clarify this is the type i am referring to. I did have to edit a 30 min death metal ep note by note, without a grid, built several studios by hand, and spent over 10 years as an audio professional. If thats not masochistic, im not sure what is :\

    41dkOGqluaL._AC_SY400_.jpg



    51F8hwyReZL._AC_SL1500_.jpg
     
  10. dvdhawk

    dvdhawk Well-Known Member

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    How many watts (0r amperes) does your gear list add up to ? Add them up. Computers, displays, drives, routers, interface, 11R, monitor speakers, other processors, all of the sensitive gear.

    US line voltage being 120v, the 1000 watt IS1000 has a theoretical max of 8.33 amps. It might be overly cautious, but I'd be inclined to avoid going right to the 1000w threshold and leave 10% headroom. (900w / 7.5amp total)


    Ideally, you'll have one central source of power and one path to ground for all of your interconnected gear. Unless you've got a major problem somewhere, a decent AC line conditioner - the kind without a dedicated iso transformer (ETA, Furman, Tripp-Lite) will usually be all you need for most residential electrical distribution. UPS on your critical computer components is a no-brainer. If for no other reason so you don't lose anything if/when the power flickers.

    If I already had a great sounding control room and wanted to go the extra mile, I'd look into a balanced power unit instead. It uses Common Mode Rejection to remove noise from the electrical supply in the same way a balanced cable cancels out noise. I swapped my 20-amp Furman balanced power supply to Chris (Audiokid) a while back, and will replace it when I get to the point I have a suitable place to use it. At the time @audiokid was set up for very critical listening and said he could hear a drop in his noise floor when he put in the Furman. That was with high-end gear to begin with. Maybe he'll chime in with his final assessment of how effective it was overall.

    In addition to breaking the physically connection, isolation transformers will eliminate EMI/RFI noise and should be equipped to handle surges and spikes too.

    Try to stay away from circuits with the other usual residential noise makers (furnace, AC, fridge, oven, pump - anything with a big motor, fan, or heating element that cuts in and out really).

    Isolation transformers can be useful. If I'm putting a system in new building for work and budget permits, the electricians will put in one big transformer to isolate an entire A/V sub-panel. That dedicated panel will power everything A/V related and keep us separated from the institutional sized kitchen appliances, HVAC, and everything else. By the time you connect an audio console, plus a computer system that is used as a sound and video source at FOH, plus an amp rack somewhere backstage, plus a variety of electrified instruments and amps on stage, plus one or more projectors in the rafters, - that's a lot of potential for noise if they're not all coming from the same sub-panel with the same path to ground. They are all tied together by virtue of their hardwired shields.
    Even though a lot of these new building projects are big 3-phase systems with a lot of potential for polluted power, a iso transformer is usually not a budget priority and we just do without one. In the A/V guy's perfect world, he'd have one leg of the 3-phase just for his equipment and put the rest of the building on the other 2 legs. However, electricians (rightly) want to distribute the building's load evenly over the 3 legs. For a new building (with or without an iso transformer) I'd specify a single electrical sub-panel dedicated to all the A/V gear, (FOH, backstage, on stage, and overhead receptacles), which is 99% of the battle. I also always use Furman and ETA power conditioning and sequencing at FOH and in any outlying racks, plus small conditioners at the projector locations. When I'm putting a system in an older building (which is way more often than new buildings from the ground up), we do without iso transformers and almost never have a dedicated sub-panel for A/V gear. Even then, I rarely have problems that can't be solved with the ground lift switch on a DI box. The only time I can recall a noise gremlin that had me pulling my hair out, it turned out to be a faulty, (brand new) soundboard.

    It doesn't make a lot of sense to me to use multiple iso transformers. If the gear is centralized, I think it would be less expensive to buy one big iso unit rather than two small units. If it's gear scattered all over the house, I'd use the iso in your primary DAW location and regular line conditioners everywhere else. Multiple power conditioners seems perfectly reasonable to me. I have one, or more two, in every rack I own.

    MIDI cables usually do ground to the chassis of the gear they connect together, but if you've done everything else right (a single power source with one path to ground) it shouldn't be an issue. I wouldn't bother filtering the wireless bluetooth stuff that is never physically interconnected by wire.

    And somewhat ironically, the kind of big isolation transformer that someone might use to remove noise and hum from their sound equipment will often generate a mechanical hum of its own.


    RELEVANT READING MATERIAL
    https://www.apc.com/us/en/faqs/FA157465/

    https://download.schneider-electric.com/files?p_Doc_Ref=SPD_NRAN-7NB2FG_EN

    http://www.datcominc.com/edit/files/emerson-marketing/Comparing Transformer-free.pdf
     
  11. paulears

    paulears Well-Known Member

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    Separated technical earths (grounds) are quite rare now in the UK. The BBC used them as standard but now grounding arrangements tend to be done to our version of 'code' so our standard system is with a single earth, usually at the point of entry of the cable where neutral and ground are joined together - this ground reference is then distributed to all outlets in use. We have a slightly different system for separate outbuildings, where they usually have their own bonding to ground that prevents extending the first buildings ground to cover the new extension to the perimeter of the common ground potential. My studio is within the existing property boundary so uses the distributed earth, but for me this is actually very close - the studio being right next to the electrical intake - so my ground is only ten feet or so from the one that services the entire building. Single phase of course. 3 phase is very rare in any domestic property here. Our typical intakes for domestic property are 60-100A, single phase 230V (although it's actually 240V, but in the European Union we are 'harmonised', so we call 240V, 230V and our euro neighbours on 220V also call theirs 230V so we are all happy. )
     
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  12. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Thank you sir. I will make a spreadsheet of the wattage/amperage as you and boulder suggested, even tho its largely just academic at this point. Off the top of my head im looking at over 3000w worth of computer psu's with 800-1500w of actual draw. (I over spec'd for psu efficiency)

    I thank everyone alot for helping on this topic! Based on what ive been told i think ive found a reasonable approach.

    To start:
    Power conditioners everywhere. No iso xformers for the machine room/slave rack/ secondary gear. For the main daw, iso xformer if needed.

    For the new place, ill spec the typical balanced load for each panel, and isolated ground (star grounding) for the studio sub panel, and good moderate price power conditioners for everything.

    A backup power system will be spec'd for the entire house, likely consisting of an emergency generator, and a battery backup/powerwall tied into my solar/wind power system.

    Ill have to learn how to verify the quality/purity of my power, and then take further action if needed.

    My experience with a leaky power xformer on the at the wave cave was horrifying until one day they replaced it and viola' noise not an issue! At Normandy, such great care was taken back when they built it, it was a dream. That was my aha! moment about how clean power sounds more solid, and has more of that elusive "thing" that's on good recordings. Its more than just lack of hums, everything sounds more "there".

    Anyway thanks again everyone for your thoughtful replies and time. Next step is to learn how to check the quality of my power, and try to actually understand power better than just what i parrot from books.

    Cheers!!!
     
  13. paulears

    paulears Well-Known Member

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    You'll be surprised how little power studio kit really consumers. My computer has a 300W PSU, and it takes no more than 160W even when running UsB powered devices. Power amps are very good examples - not the Class D one, but good old heavy transformer PSU versions. I've a PA rack with amp values that add up to 8500W. turning the entire rack on by the wall socket trips the 16A MCB with the surge current, but since running, with loud red lights everywhere too loud music driven g it hard, the total current is below 10A. Our three phase power is meant to run as balanced as possible in venues this is rarely possible, and I'm just not convinced that power conditioners and other interesting devices are actually needed. A friend exulted the improved quality running with his UPS gave the mixer and audio system components. Then he discovered that it was not a regenerating type, and his kit was running off plain mains power, with the UPS kicking in if it failed.
     
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  14. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Right, this is common because computer psu's run most efficiently at 40-60% load. Many off the shelf computers won't leave adequate headroom, which often results in a more noisy fan, and earlier component failure

    This trend my die off since modern power supplies are much more linear in their efficiency curve. However many units have fans that wont kick in until 25% or so draw, so it can be advantageous for people who need a silent computer.

    A common 15A breaker is designed to deliver 12A.

    One thing i very much appreciate about QSC amps is they're reccomend breaker size for each model amplifier. They also include wattage draw ratings at 1/3, 1/2, and full power.

    Ive not had great results with them as hum removers, but my monster power conditioner did shut my stuff down when a place was supplying too much voltage. I can't say ive ever heard a difference, even with $2k voltage regulators.

    That said, i like having the front mounted power switch, and rear plugs for the gear.

    I understand confirmation bias is a real thing.
     
  15. dvdhawk

    dvdhawk Well-Known Member

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    Even the best power conditioners are not going to be a panacea to cure every electrical problem. They do what they were designed to do reasonably well.
    A moderate priced model is usually all I would recommend, unless we need power sequencing for an installation.

    They will not eliminate a ground loop. That's a separate issue with known cures.
    They will not keep a piece of equipment with a poorly designed power-supply or poor shielding from making the noise it generates internally.
    They will not help in the event of a brown-out. (You need a voltage-regulating line conditioner for that.)

    They will protect you from spikes, surges, and over voltage that originates from outside your system.
    They will remove the majority of noise on the AC sine wave that originates from outside your system.
    They are a much better way to distribute power than plastic, dollar store cheapo power strips.

    I'm sure all of your audio gear is up to a reasonably high standard. Typically, electrical noise comes from other things (refrigerators, furnace fans, light fixtures) outside of your audio system. I've been told that electric providers often use the 60Hz sine wave (US) as a carrier for a tone(s) that lets them monitor their system for outages and other problems.
     
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  16. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    Do you know if the economy model furman conditioners reasonable performance for the dollar? I believe they are the "merit series". Its what i had in mind for this rough and tumble setup.

    Good to know my old one was doing its job!

    This is cool. Would this be audible? Or it it one of those things that's super subtle or becomes noticeable after the (noise) is stacked up on many tracks, or shows up suddenly when the track gets super compressed? Is it one of those things that just shows up on a scope? Either way less noise is a good thing imho.
     
  17. cyrano

    cyrano Active Member

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    You need to test if it's a solution to your problem. Transformers are very different. The kind of noise they stop is different too.

    And if you start including DC to AC converters it's an entirely different thing. Chances are a UPS will add noise in stead of eliminating it.

    But, again, every setup is different. And if you haven't got a problem, it's a waste of time and money.
     
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  18. kmetal

    kmetal Kyle P. Gushue Distinguished Member

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    I certainly don't want to treat problems that dont exist!! My biggesr concern is the air conditioner and mini fridge, which are likely to be in the same room. I could run an extension cable to a different room/circuit but id prefer not to have to.

    Do you think i should test by just setting up the gear, or is there something i can do ahead of time?

    I will likely be moving the main daw into a different room or two as this place gets renovated. I also anticipate having the slave pcs in a seperate room or closet.
     
  19. dvdhawk

    dvdhawk Well-Known Member

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    Pros and cons to everything, Kyle.

    The Furman Classic series offers higher levels of noise filtering, and surge protection than the Merit series, but if you plan to plug the Merit into another conditioner or iso transformer upstream then it doesn't really matter.

    The Furman Classics provide protection from sustained over-voltage condtions, and also use surge protection that is "non-sacrificial, meaning it doesn't slowly get destroyed doing its job. The Merit series does not list either of those more advanced features, so I assume they just work like any other normal surge protector. Normal surge protectors use simple MOV (metal oxide varistors) on the Line to absorb the spikes. MOVs are cheap and they're effective for basic surge suppression, but every hit they take slowly chips away at their integrity - until eventually they burn out. Also as far as I know, Furman (like most manufacturers) only protects the Line and ignores the Neutral and Ground.

    Classic v Merit.png

    The ETA PD8 models have always been my personal choice for bang-for-your-buck power conditioners. The older ETA versions I've used also apply filtering and surge protection to the Neutral, and the Ground (in addition to the Line). Now, there's a newer version of the ETA (PD8A and PD8LA) that I haven't used yet. I don't know for sure if all the primary features have carried forward to the newest models.

    You're going to need a whopper of a UPS unit for 1500-3000watts of computers + everything else and a 30A (or more) circuit to power it.

    How Do I Properly Size My UPS
     
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  20. paulears

    paulears Well-Known Member

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    I think before I did anything, I'd get the gear running. Let's look at the equipment. Air-con and a fridge is really just a motor - the compressor, and perhaps the switch contacts that turn the thing on and off as required. In this day and age, suppressing these transients is not exactly hard for a decent manufacturer to implement. The noise source would be the hard edge of the waveform cutting in part way through the cycle, and on a power system with sufficient diversity, this is very unlikely to have detrimental effects on other equipment. In the UK ring power circuits are the norm, so we'd have perhaps dozens, maybe now with wall wart type power supplies, maybe 30+ (using my house as an example) so noise sources are plentiful. With new AC and the fridge, clicks, pops or noise really should have been designed out. I'd 100% not be spending money until a problem surfaces - and I think on a new build with new electrics it's very unlikely.
     
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  • AT5047

    The New AT5047 Premier Studio Microphone Purity Transformed

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