Will an ISO Transformer Stop "Off Gear Distortion"? (Public)

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  • เผยแพร่เมื่อ 19 ธ.ค. 2024

ความคิดเห็น • 105

  • @Diggs5012
    @Diggs5012 2 ปีที่แล้ว +10

    Thanks Dave for including the Xenyx basic analog mixer! You covered a wide and very useful array of plug ins/outs for all that crave knowledge. Peace

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +2

      Cool cool

  • @imark7777777
    @imark7777777 2 ปีที่แล้ว +1

    I just remembered a real world experience I had and I wish I had the foresight to take a picture of the mixer.
    I was brought in to help a church and I noticed one of the channels sounded really weird with whatever device was plugged into it at the mix position. After going over a few things and thinking maybe that's just a bad channel I wondered up on stage and noticed there was a disconnected not used DI plugged into a wall jack which corresponded to the cable that was plugged into the mixer. For whatever reason the XLR jack on the mixer shared some thing with the quarter inch input as well. I wouldn't say this was a cheap mixer but the remedy was to unplug the device from the wall jack and subsequently not have that snake Channel plugged in.
    I want to say it was one of those RadioShack/realistic cylindrical DIs, and a wireless microphone receiver on the mixer.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      interesting and lingering bit of gear can be gremlins

  • @Edwin-van-der-Putten
    @Edwin-van-der-Putten 2 ปีที่แล้ว +4

    Wow! Dave... I wouldn't think powered off stuff would influence the sound signal... Thanks for another entlightning video!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍👍

  • @Deraco1
    @Deraco1 ปีที่แล้ว +1

    Interesting but this makes sense because of the preamps on the mixers drawing some of the signal voltage. Strangly enough the small mixer didn't cause an issue at all. i guess maybe on how small the pre-amps are?? Not sure. Be interesting to know the Ohm load change readings when doing so

  • @Scotty_Russell_Music
    @Scotty_Russell_Music 2 ปีที่แล้ว +1

    Good video. With the recent rise in UK energy prices I have started only switching on whatever gear I'm using that session. I hadn't really ever thought about "off gear distortion" but I will now. Cheers.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      🔧🔧🔧

  • @HominidInterneticus
    @HominidInterneticus 2 ปีที่แล้ว +1

    Glad you got your channel back. I hope you get your old videos back

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      🔧🔧🔧🔧🔓🔓🔓

  • @drumforfun19
    @drumforfun19 2 ปีที่แล้ว +1

    This is so cool. You're like the Bill Nye the Science Guy of Audio Engineering. Always doing the coolest experiments and making me think about audio in a new way. Thank you Dave!!

  • @cbvb
    @cbvb 2 ปีที่แล้ว

    Dave, off topic question: I need to make a new cable in order to use my vintage Electro-Voice 676 microphone that has a 91-MC4Female 4-pin connector. I wanna use the MC4Male connector from the vintage cable that came with the mic to make a cable with a male XLR to use with modern equipment. I'm assuming the vintage cable has 4 wires while the XLR only has 3 wires. What's the best way to go about making essentially a MC4 to XLR cable? Thanks!!

  • @dougaltolan3017
    @dougaltolan3017 2 ปีที่แล้ว +2

    Electronics time....
    The cause is how the input is designed. For low level (high impedance) inputs it can be desirable to buffer the signal before anything else. That can be done with an opamp. The problem is that the signal will be diode clamped to the power rails (chip inputs do that). When the gear is on that clamp is to +/- 15V when off it is +/- 0V.
    Lìne level inputs don't require immediate buffering and are usually equivalent to a resistor load to ground.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Agreed, and what is interesting and important is that there is almost no documentation or awareness of this.
      Have you seen this listed anywhere?
      How are non electronics people supposed to know this is an issue to look out for?

    • @dougaltolan3017
      @dougaltolan3017 2 ปีที่แล้ว +1

      @@DaveRat not seen any information, input impedance when turned off just isn't in any kit's tech spec (well, not at professional audio gear level)
      All I know is a good grasp of electronics and can spot ooopsies like this pretty quick.
      I'd be interested to see what trace you get on a 'scope when it's clipped. My money is on sine wave fairly hard clipped to +/- 0.7 or 0.2 volts.
      As for mere mortals.. Just gotta suck it and see.
      Active DI boxes could be cajoled into fixing this if you can run them without phantom power.

  • @DeadKoby
    @DeadKoby ปีที่แล้ว +1

    I run sound sometimes for smaller shows.... if you learn ANYTHING from Dave, TEST your gear/rig in many scenarios so you KNOW what works and what doesn't. This way you won't be losing your mind troubleshooting at the show.

    • @DaveRat
      @DaveRat  ปีที่แล้ว

      👍🤙👍

    • @DeadKoby
      @DeadKoby ปีที่แล้ว

      @@DaveRat Yet so often, I see some musician bring in some piece of kit that's going to "improve things" and insists it be hooked up right away... There's no time for the engineer to test it, and it does some crazy stuff messing with the musicians. On my rig, I know every inch of it, and I've repaired it a few times. Is it a "great rig"??? probably not, but there's been some great sounding shows using it, so Yeah, it IS a great rig for me anyway.

  • @imark7777777
    @imark7777777 2 ปีที่แล้ว

    This is exactly what I was thinking when the problem was raised a few videos ago. I love this channel for the crazy stuff like this. I just wish I could watch it more.
    My original thought was that it would be affected unless it was transformer isolated although it really depends on the quality of the transformers to further isolate unless one end of it is acting as a load in the off State.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      The higher the quality of the transformer, the better it will be at passing distortion through it. A perfect transformer would pass distortion at the same level as a hardwire

    • @imark7777777
      @imark7777777 2 ปีที่แล้ว

      @@DaveRat oh interesting so it has the opposite from my hypothesis.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍👍

  • @jdrissel
    @jdrissel 2 ปีที่แล้ว +1

    This is good to remember. I remember many years ago I was trying to run down some alternator noise in a car stereo with three separate amplifiers. The weird thing was unplugging the RCA's any one of the three would stop the noise. But then I noticed that turning them off wasn't the same as unplugging them and there was one of them that stopped it when it was turned off. The other two did not. Strangely this amplifier was actually a duplicate of one of the other amps in the system so I swapped them. The behavior persisted so I sent the amp back to the manufacturer and put in a new amp of the same model. There was no noise with the new amp. The manufacturer found a power supply capacitor installed backwards on the circuit board. I can't say for sure if that fixed it because I never put it back in that car but we did sell the amp in another vehicle and it did not have that problem. Someone got a very nice amp at very nice price because of that...

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Super cool and appreciate the info/story!

  • @schattenheim
    @schattenheim 2 ปีที่แล้ว +2

    Again a great analysis 🧐 .... you are the rearl soundhuman (great t-shirt by the way)

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Awesome and thank you!

  • @EndritVj
    @EndritVj 2 ปีที่แล้ว +2

    Always interesting stuff. Thanks Dave!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍👍

    • @EndritVj
      @EndritVj 2 ปีที่แล้ว

      @@DaveRat Dave, have you yet tried L-Acoustics K3? An irrelevant question to this video subject but I am not finding an old comment where I asked you and you had not tried them yet at that time.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      We bought a K3 system and it is in the Sonora Tent at Coachella currently

    • @EndritVj
      @EndritVj 2 ปีที่แล้ว

      @@DaveRat I would love to hear your opinion on this. My company currently owns 18 pcs of Kara II, 6 KS28 and 12 SB18, including some other LA speakers. We are looking to buy initially 12 pcs of K3 and use the Kara together with it, mostly for outdoor setups with up to around 10K audience. Would the K3 make any difference in this scenarios or is it better to expand the Kara system to 14pcs per side? Our main objective is to reach a minimal distance of 70M coverage without delay towers and without squeezing the system to the max. Does the K3 sounds much better than Kara, with more presence and more similar to the K2 tonality?

    • @EndritVj
      @EndritVj 2 ปีที่แล้ว

      @@DaveRat Maybe my question is difficult to answer but I would love to hear your opinion on K3.

  • @cameronproaudio
    @cameronproaudio 2 ปีที่แล้ว +3

    It's not just inputs getting loaded down when gear gets turned off that can be an issue. I have a crappy old Mackie CFX series mixer I keep plugged into my Rat PA for small stuff when not using a larger console. I'll often have self powered speakers in other rooms feed from the sub group outputs on the CFX. If the CFX is powered off, the speakers in the other room will buzz if left on. They're coupled to the CFX with Whilrwind ISO1 transforms, which doesn't help as in your demo here. I'm assuming the issue is that the outputs are all 'pseudo balanced' with only pin 2 having an active driver and pin 3 with a resistor to ground to 'match' the impedance of the hot pin. And that hot pin looses it's rated impedance when it's powered off relative to the fixed cold resistance/impedance. It's buzz city when mixer is off. I can always tell when I walk in the building if someone shut off the mixer and not the powered speakers ;-)

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      👍👍👍

  • @coastben
    @coastben 2 ปีที่แล้ว

    Hi Dave. Something I have come across and I reckon it would be a huge advantage to go through it for the audio community as we all use it.
    Some small digital opamps used in mobile phones and Bluetooth adaptors that are normally used to drive headphones or get used in this case as an auxillary out, when summed to mono via a cable, create very audible distortion. I would assume this is a byproduct of the negative feedback circuit doing its job. In normal analog circuits this is fine as and difference between left and right are fought about linearly, where as in the class D world, well that transition doesn't go so well.
    So, as an example, if you have a 3.5mm coming out of a phone, to two rca's, then go from 2 into 1 as many people do if you just want a bit of bgm, any difference between left and right is pronounced as distortion. Anything common to left and right comes out fine.
    I found that by adding a 1k resistor to each signal line prior to summing them fixes the problem.
    Logitech Bluetooth adaptors and iPhones (that still have a 3.5mm jack) seem to be the worst. Funny, as they are probably the most used devices.
    Thanks.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Interesting I'll ponder that

  • @monkeymhn7
    @monkeymhn7 2 ปีที่แล้ว +2

    Ok now I have proof for those who don't understand the need for distro amps in line level split situations. Not only do they allow me to deal with level ,impedance, and wiring configuration matching they isolate a single source from the gremlins you demonstrated

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      There are assets and issues with adding distribution amps. Added complexity, cost, noise and something else that can fail versus added control, improved isolation and eliminating t lge issue of one bad line taking out the everything.
      Selecting the best method for the particular application is important.

    • @monkeymhn7
      @monkeymhn7 2 ปีที่แล้ว +1

      @@DaveRat agreed . I like the distro in line level situations .

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      🤙

  • @MrBrunoRenee
    @MrBrunoRenee 2 ปีที่แล้ว +1

    Super nice video thanks

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍👍

  • @stevenewtube
    @stevenewtube 2 ปีที่แล้ว

    Yes very interesting indeed. Is it impedance matching, when gear is turned off? Your “AC across the transformer” comment was one of those, of course, that’s right, oh my goodness that explains a lot moments for me . Cheers mate.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      People telle it is some protection diodes on some mic preamps that cause it

  • @miicar204
    @miicar204 2 ปีที่แล้ว +2

    5:34 Tricked me too for half a second...then i laughed. done this kinda thing to myself way more then i'll ever admit!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      👍👍👍

  • @mycosys
    @mycosys 2 ปีที่แล้ว +1

    Really glad you got your channel back so fast. I'm the Aussie wierdo that called.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Thank you thank you and much appreciated!!!

  • @Solmbarnes
    @Solmbarnes 2 ปีที่แล้ว +1

    Very Interesting indeed.
    Anouther very helpful tool for my troubleshooting box.
    Thank you.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍

  • @peniku8
    @peniku8 2 ปีที่แล้ว +1

    I've had this issue with a Behringer headphone amp, hooked up to a patchbay in parallel with the main out (when powered off). It was inaudible, but I happened to have an analyzer on the signal and was wondering why I was seeing unusually high distortion figures.
    Took some time to track that down; these kind of hidden, unexpected issues are the worst!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Interesting and yes, that is exactly the scenario

  • @Josh-ri7hy
    @Josh-ri7hy 2 ปีที่แล้ว +1

    Will you please do a video measuring signal distortion comparing using a line level input vs a mic pre input? Like if you are bringing your own console into a venue… and they don’t have line inputs… does it really make a difference? THANKS DAVE!

  • @fullracecam1
    @fullracecam1 2 ปีที่แล้ว +2

    I am completely blown away by this, I was certain it would have no effect with an iso split. Wow!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Cool, yes, an audio transformer looks pretty much like wire to audio signals.
      For DC a transformer is an open circuit from input to output.
      And like all passive devices, a transformer is bi directional

  • @DrewAspinwall-1
    @DrewAspinwall-1 2 ปีที่แล้ว

    Press box splits come to mind as affected scenarios. We don’t have any control over their gear or usage; and aren’t directly monitoring that output.

    • @kirbymurdstone4925
      @kirbymurdstone4925 2 ปีที่แล้ว +1

      Most good press box splits have an active buffer amplifier for each output, thus would be unaffected by this phenomenon.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Also in my experience, most camera crews all want mic level. And mic level does not seem to be impacted by this.
      We have been running hardwire press boxes without issues for many years.

  • @grkl4439
    @grkl4439 2 ปีที่แล้ว

    This is very interesting! I've heard this effect before as well in different scenarios. It would be interesting to know what in the circuit design of some pieces of powered off gear contribute to the load down effect and others do not. Instead of an iso or hardwired split, I was wondering if when using a distribution amplifier or an active split, if that would resolve the issue.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      Scam the comments below. There have been quite a few people explaining what the cause is. Most say it's diodes that get energized and load down the signal

  • @legacyShredder1
    @legacyShredder1 2 ปีที่แล้ว +1

    You're now making me wonder if this is affecting anything in our recording studio. We have tons of gear with splits.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      It's worth a look, it's a good thing to be aware of and may save ya some grief someday

  • @RufusKSala
    @RufusKSala 2 ปีที่แล้ว +1

    Isn’t the Radial JS2/3 a mic level device? Or did I miss something? The Radial LX2/3 is line level splitter product. And which console was on the direct out versus one of the iso outs?

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Hmmm, so do you think that using a different transformer will solve the issue?
      As far as which console is on the iso, they both were for the test but the issue happens no matter how you connect that or any iso. Either can be iso, both or neither.
      The turning off the X32 loads down the signal and causes distortion and since transformers pass audio bi directionally, the issue passes through the transformer.

  • @Kitzy
    @Kitzy 2 ปีที่แล้ว +2

    So what is the benefit of using an iso split vs. a hardwire split, especially in the context of separate FOH and monitor consoles? What potential problems can the iso actually solve?

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Hello Kitty, transformer isolation can give isolation from ground loop hum and buzz as well as DC offset issues.
      So if you have gear running off of different power sources, transformers can reduce issues associated with the different grounds.

  • @samsonstrike
    @samsonstrike 2 ปีที่แล้ว +1

    THX!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      🤙🤙🤙

  • @GingerDrums
    @GingerDrums 2 ปีที่แล้ว +1

    Inredible as always. Mixing engineer here sat in Berlin with a question... Does this apply to my outboard stuff too? Should I be powering everything on every time? Cheers!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      It could, some gear does it and some does not. Though so far it seems that mic preamps are more likely than line level inputs. I have not found a line level input that does it yet.
      I test a drawmer compressor and some amps in the video

    • @dougaltolan3017
      @dougaltolan3017 2 ปีที่แล้ว +1

      Only if your outboard gear is fed with a split, or your desk has very poorly designed outputs.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      Driving multiple rooms with a split or driving multiple powered speakers or consoles with a split is quite common. Turning one or more of the units off when not using them is common as well.

  • @angelorasmijn7306
    @angelorasmijn7306 2 ปีที่แล้ว

    Man, you are just such a cool dude! 😎

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      I appreciate that! 👍👍👍 Angelo Rasmijn

  • @sugarbeat8586
    @sugarbeat8586 2 ปีที่แล้ว +1

    Hi Dave nice work as usual. What happens if you swap the ISO outs? Radial schematic looks like it has a passive split on one side. Have you tryed a Lundahl based splitter with several iso windings? I have never encountered this issue in my Lundahl based splitter. Its one passive(FOH)...(2) true iso....Monitor and Truck. I think the part number is an LL1590

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      It really does not have anything to do with brand and in fact the higher quality the transformer, the better it is at passing audio, the better it will be at passing the loading that causes the distortion.
      Transformers are bidirectional and pass electricity in both directions and any output driving the transformer will see the load on the other side of the transformer, so...
      If the transformer is properly working, a change in the load will impact the circuits driving transformer. And if the circuit driving the transformer is impacted, then everything that the driving circuit is connected to will be impacted

    • @sugarbeat8586
      @sugarbeat8586 2 ปีที่แล้ว +1

      Thanks for the reply Dave...email prose never one of my strong points. My question was not on brand but on if you swapped the passive split side of the Radial did the loading and distortion follow the swap. I totally missed you are using a JS3 and both of the transformer ISO outs.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      What is occurring is the console that is off is loading down the signal and causing distortion. So it doesn't matter whether or not the console is hooked up hardwire or through a transformer the loading down of the signal still occurs. So it doesn't matter which console is transformer isolated or if both are isolated, the issue will still occur and impact all things connected to that signal.
      One way to solve the issue would be to use a separate active line driver to each console.
      but as long as the consoles are connected together through hard wires or transformers or even if they were capacitor coupled the issue would show up everywhere.

  • @thenoisynomad
    @thenoisynomad 2 ปีที่แล้ว +3

    Thanks Dave! Does this apply to a monitor engineer that is not powered up? I’ve had issues at front of house when my monitor engineer is napping and am wondering if an isolation transformer may actually help in that situation 🤪

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +4

      Cattle prod may work for that

  • @Foderick
    @Foderick 2 ปีที่แล้ว

    so many of your videos i tell myself - 'i know whats going to happen'
    and then i end up being wrong

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      👍👍👍 Foderick

  • @dighawaii1
    @dighawaii1 2 ปีที่แล้ว +1

    Very cool :)

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍👍

  • @magoostus
    @magoostus 2 ปีที่แล้ว +1

    probably couldve heard the distortion a lil' better if ya put a narrow notch filter EQ to remove the test-tone frequency right on the input channel there. also, a FFT spectrum analyzer would show distortion way before it's even audible.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      My goal is to use the cheapest and most readily available gear possible to demonstrate complex issues with minimal complexity.
      Such that anyone can easily replicate.

  • @johnwilliamson467
    @johnwilliamson467 2 ปีที่แล้ว +1

    about 17 dbu . I can see the mic pre being a much different load from a line level input as you showed . Trust but verify . Ronny Regan of all people said that it apply.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      👍👍👍

  • @juanmanuelcasta2257
    @juanmanuelcasta2257 2 ปีที่แล้ว +1

    Are you here again?? Hope more content!

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      Yes, will post soon

  • @artysanmobile
    @artysanmobile 2 ปีที่แล้ว +1

    Yamaha sweats the details.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      👍👍👍

  • @artysanmobile
    @artysanmobile 2 ปีที่แล้ว +1

    Transformers can’t perform magic. A mismatch at the output winding is reflected back to the primary precisely. What they CAN do is deal with differing ground potentials which is a very real issue in complex and large setups. Not much of an issue at your band’s club gig. This is why the most effective use of an audio transformer is at the output of a near-zero impedance amplifier. This drove me to develop at great expense an active splitter with driven transformer outputs for my Artisan Mobile. We often dealt with half mile analog snake runs, literally no chance even to troubleshoot. Split problems virtually vanished from the day I put it into play. Nevertheless, tech moves on and it is obsoleted by issues of weight. The two splitters and 56pr mults weigh just over half a ton and I’m over that.

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว

      Good stuff and agreed

  • @torbjornandersson5997
    @torbjornandersson5997 2 ปีที่แล้ว +1

    Sometimes I wonder, how much of the so called "professional gear" is actually professional gear?

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +1

      Ha! Yes, some gear called pro is not even close

  • @lambda7652
    @lambda7652 2 ปีที่แล้ว +1

    No the Transformer will not help or only a little bit.
    I hope i’m right... if not this post will be edited. :P

    • @DaveRat
      @DaveRat  2 ปีที่แล้ว +2

      👍👍👍