Understand Audio Phantom Power + Demo
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- čas přidán 27. 07. 2024
- What are the dangers and solution to using phantom power?
How does phantom power work? What happens when sending phantom from more than one console to a mic? What happens sending phantom down an unbalanced mic cable? Can phantom power destroy a mic?
00:00 What is phantom power?
01:57 Phantom power is high voltage, low current
02:59 Phantom measurement setup
04:21 Measuring phantom power output
04:56 Phantom power wiring
06:15 How phantom powers a condenser mic
08:43 Plug in a condenser mic an measure phantom
10:40 Dynamic mic wiring
12:23 Phantom to a dynamic mic
12:36 Dangers of phantom on dynamic mics
14:56 Phantom from two consoles wiring description
15:37 Impact on phantom when second console is connected
17:03 Test and measure phantom sent from two consoles to the same mic
18:48 Parallel vs series
20:32 Phantom and isolation transformers
21:15 Summary
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In all my years of Audio engineering (40 odd)I have never been able to grasp the concept of phantom power workings. This has explained it in the most simplistic form ever. Thank you so much and keep up the great work.
So cool and thank you! Honored
PLEASE Never Stop doing these videos!
After 30 years, you always teach me something that I didn't know, that I should have known, that makes perfect sense, but somehow I feel like I'm an apprentice. That's simultaneously humbling and exciting. And we're talking about Phantom Power of all things!
Awesome, thank you!
I gotta say when you pulled out the Neumann I'm like whaaaaaat.
"If we're going to use something to test, let's use something expensive to do it with."
Lol. You are hilarious my friend.
Fun!!
Thanks Dave. I really enjoyed this chat and demonstration. I've been running PA's and doing all sorts of sound for over 40 years and never really understood what was (technically) going on under the hood. In saying that, I always made sure that my pin to pin wiring was spot on and never had any major issues when running condensers with dynamics. Your bench top demonstrations are excellent, and show that the principles do not need a massive rig or console to explain. Keep up the discussion. Cheers ...
Thank you Perry
Great video Dave. You really made it easy for me to understand how phantom power works, especially with the drawings. Cheers for that.
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Amazing to get these graduate level info packets from the icon himself.
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Thanks again , nice experiment. The loading of the second console un-powered phantom is due to the two , normally 6k8 , resistors used and as you showed us the phantom voltages combine when both on to share the microphone load. The idea of phantom power came from Telephone/Telegraph balanced circuits for either powering up repeater circuits or adding dc signalling to a balanced transmission line. Cheers Dude
Awesome. Thank you Dave
For the more technically curious, the actual 48v power supply in the mixer feed each channel separately through resistors, typically 20k ohms or more, so that any difference in the multiple supplies will be dissipated in a small amount of heat, and not damage the microphone or mixer. Even If one or more wires is shorted to ground, like using an unbalanced cable, it will not greatly affect other channels. The only possible damage would be if the microphone voice coil or transformer cannot handle the current. For example , a typical mixer feeds pins 2&3 through 47k ohm resistors, and a typical voice coupled is 200 ohms, so 48v would place about 0.2 volts across the microphone voice coil. It would not be healthy, and would push the coil against the end of its space. It would also generate some heat. The actual damage would depend on the specific microphone.
Thanks for the excellent demonstration and keeping it simple.
Agreed and I believe the phantom power spec calls for 6.8k ohm matched pair resistors
@@DaveRat thanks, I couldn’t remember off the top of my head.
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Really cool video. Appreciate the intentional fault to show the mic coil popping.
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Best explanation of this ever. Thank you
Thank you, big smile
Very brilliant explanation. Now, I will not be afraid that my house mixer would not damage the recording mixer even without isolating transformers! Thank you!
Excellent
nice! the more I watch your videos, the more I realize how important it is to get a practical understanding of electrical connections and signal flow.
So cool and yes and thank you!
You rock. The deep dive, your personality, and the outro with low freq sweep etc., I love it!
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Great video! There's a lot of information here I've kind of put together over time (sometimes from watching you), but it's great having it all together and verified.
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i can't get enough of your videos. does the audio engineering rabbit hole get any deeper than this!
Ha! Awesome!
This brings back memories of when I was a kid and tore apart the microphone that came with my dad's cassette recorder, saw it was dynamic, and realized that it looked just like a tiny speaker. So I plugged it into the output jack of the recorder and found that I could hear the sound on the tape through the microphone.
I'm guessing that the 48V phantom power voltage came from the phone company, that used (and still uses) a -48V battery to power all central office equipment. Long ago (like before any of us were alive), long distance calls used to use a 4 wire cable. When the need for more circuits arose, they added a third circuit (a 4-wire cable could handle 2 calls, just like a regular POTS phone line can) by putting center-tapped transformers at both ends and connecting the third line at the center taps. Because the AC voltage from the center tap was the same at both ends of the other voice circuits, it canceled out and couldn't be heard. Likewise the voltages on the two circuits became zero at the center taps, so there was no crosstalk in any direction.
I live this!
Your post brings back memories for me. As a child, I also tried the dynamic-mic-as-speaker trick. My favorite "transducer repurposing" is to use a closed-back set of headphones as a microphone to pick up heartbeat sound.
In the late 70's when I was studying for my EE degree and working various jobs, I had a short stint at the local telephone company's CO serving the Redmond-Kirkland, WA region. In those days, the equipment was all relay-based, and when you walked into the office, there was a constant noise that sounded like a waterfall. The power room had a huge stack of batteries kept under constant charge by true behemoth TR units, and a diesel generator just outside for longer power interruptions. The 48V power came into the switching office on a pair of copper plates - true power "rails" the likes of which I've never seen since.
@@marianneoelund2940 that is so so cool!
@@marianneoelund2940 That's very cool! I was a little behind you. Thanks to some experience while still in high school, I got a little experience in doing sound reinforcement and lighting, and if I had made enough money to eat, I'd be doing it today. During that time I found a volume of books in the local library called "A History of Engineering & Science in the Bell System" and read them cover to cover. That was one of the more useful extracurricular reads for me, as the knowledge that I got from it helped me communicate with telco people when I worked in TV broadcasting and IT. That's where I learned about phantom circuits.
One consulting job I had was for an ISP that was moving into an area that was occupied by a brand-new, unused Class 5 Lucent 5ESS switch that had been decertified when someone accidentally discharge the Halon. That thing had two -48V batteries, each cell the size of a small chest freezer. I was licking my chops over the prospect of using them to build a UPS for the facility (there also was a 1 MW Caterpillar Diesel generator downstairs) but whoever bought the junk switch got the batteries as part of the deal. I did manage to get a lifetime supply of silver-plated BNC connectors though. There were a lot of copper bus bars that carried the battery power around to the various cabinets. I wish I could have taken a few of those.
I don't recall if I ever was in a working CO with mechanical switching. I do recall that the Chicago Museum of Science and Industry had a piece of a crossbar switch on exhibit for a while. When you pressed the button, the frame would start making a big racket from behind a thick sheet of Plexiglas. Looking back it was amazing that so much was still mechanical back then. When we got Touch Tone phones in 1967, we just assumed that "computers" did all the work.
@@StringerNews1
The equipment I worked around was a bit more modern than the crossbar equipment. It used sets of relays as registers. If someone was dialing a pulse-dial phone and you were standing by their line equipment, you could hear the relays counting up the pulses.
Each line-equipment rack unit handled 25 customer lines, and the units were organized into sets of 20 (500 lines). Then there were up to 20 of those sets, to populate one "exchange" of 10,000 lines. The mapping from telephone numbers, to the line equipment numbers, was done by stringing wires through a set of pickup coils mounted on a large board.
I think the only computer in the office, at least for the local-line service (toll service was more sophisticated), was the one which scanned the equipment for faults and printed out messages for the service techs on a teletype machine.
Thanks so much Dave. Love these videos, they're very informative and you're an inspiration to everyone in the industry.
Awesome and thank
I am sure that until now, under no circumstances have I seen an explanation as well structured about Phantom Power as this one, particularly on the question of the interconnection FOH /MONITOR mixers.
Thanks, Dave.
Keep up your good work.
Greetings from Portugal
Awesome, thank you
HI i like how in-depth you go on explaining stuff and showing details.
Thank you!
Great explanation of the mysterious phantom power! Also like that you explained that AC and DC can both flow on the same pair of wires. Telephones, old Lionel trains and cable TV are some other examples that take advantage of this too :)
Awesome!
Awww...this is amazingly COOL !! Thank you Dave, its always pleasing watching your experiments. Keep doing this maestro and let us learn. Cheers \m/
Thank you Sunny!
This is great! Thank you for this video. When I saw the two 9v batteries in parallel, I knew exactly what’s going on.
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Brilliantly thought out and presented.
Awesome and thank you
I really enjoy your channel. I’m always learning! Thank you!
Thank you!
Great work as always, Dave!
Thank you!
If I were on the road and had money for all the good things, i would chose you. From the few videos I’ve watched, I’m convinced you might very well be one of the best sound guys out there. That’s a big deal! There are many factors to running sound setups... and knowing you’ve got a person who is a Masterful tech is relaxing I’m sure. Thank you for yet another insightful video.
Hell yeah and thank you!
Great explanation! Thank you for the time you put into these videos!
I love the question! Tell ya what, if you join and you're not happy and they don't respond all your money I'll personally send you a check for whatever they don't refund
Thanks for taking the time and trouble to do these videos. I learned some things from this one in particular. Even an ol' sound dog like me isn't afraid to admit that I can still learn stuff! Not that it's doing me any good at the moment with nowhere to apply my knowledge, but I remain hopeful.
Very cool and thank you!
Many of us share your disappointment from not being able to do live events, Carl. Just hang in there and eventually we'll all be back in action, and probably appreciating what we get to do even more than ever thanks to a shift in perspective from this weird time. Stay strong. 💪🤘🖖
Finally I have support when I’m arguing with other engineers claiming phantom power is bad for mics that don’t need it
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I'm an electrician industrial for 20 years plus and I love sound and computer networking as hobbies.of which I love doing.
I recognised a lot of what Dave was saying,and learned a few new things too..
Awesome!
Great demonstrations thank you! Dave over at EEVBlog invited Doug Ford (from Rode Mics) to explain phantom power and a lot of other microphone design considerations on the EEVBlog channel here on CZcams. I highly recommend them. (Phantom power is episode #616.)
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That's great - nice, simple and clear explanation and demonstrations. Thanks. Another 'danger' case is linking an output of one console to an input of another. I had a repair case when several balanced line outs of a large expensive Soundcraft console had been destroyed due to being connected to the balanced inputs of another console that had phantom power active on those inputs. Some outputs may be protected against damage being caused this way - but for sure not all.
Interesting. Phantom is so low of a current and should not hurt outputs. That said, I have run into situations where activating phantom caused the outputs to distort. Not personally burned outputs though.
Dave , your videos are getting better and better. I just want you to know I really appreciate that you share your knowledge!. Thank you so much!.
If you have time can you please review how to fix problems with getting pops or little shocks on the lips when they touch the mic and also noise or buzz from the monitors but not from the mains.
Yeah, I can do a pop shock vid
Thank you Dave, I loved that demo.
Thank you Ian
I love your demos Dave. Your channel is one I recommend very often thru mine.
Thank you!
@@DaveRat The pleasure is mine. I've been involved in sound in some capacity since 1996 but in the film industry since 2001 as a boom operator. Completely different world from yours but your knowledge and teachings have helped round out my sound knowledge.
@@SoundSpeeds
A most brilliant video.a superb production.
Thank you Stephen!
Super explanation. simple and easy
Thank you 🙂
Good info, looking forward to the zoom meeting tomorrow!
Thank you Neil and see you tomorrow!
Thanks Dave for your continued work. Interesting to see the dual consoles experiment with a Neumann haha
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Nice bass test in the end :D Great info, I guess someone who is an electric engineer would have known this already, but developing an intuitive understanding of electricity is Incredibly hard for some (like me) :)
Fun stuff to learn!
Great video. I learned a lot and will implement using phantom from both mixers on a non transformer isolated splitter snake I have.
Excellent
Here is a man who has been spending a bit much too long lockdown up at home going "WTF".
Yeah! Finally the time to dive in to all my curiosities!
Hey Dave, thanks for this ! greetings from Berlin
Greetings Curtis!
I wish obvious phantom power indicator lights were standard on all mixers. A pro tip for club engineers is to mark any channel on the tape when phantom is on so when the band is finished the engineer is reminded to mute the channel immediately. Experienced musicians know that they need to make eye contact with the engineer before unplugging a hot phantom powered instrument, but this will inevitably slip by the most seasoned sound engineer, and that painful pop is a real vibe killer. It happens to me occasionally when someone starts chatting with me at the board at the end of a set and I get distracted.
Whilest I personally don't worry too much about phantom 9n or off, I do make sure channels are muted before swapping mics at a gig. And if I see the peak lights flash on a muted mic, there is a good chance phantom is on.
Phantom power is about as dangerous as drinking a soda in a car, all good except if things go terribly wrong
Two things : Red should be pin 2 (hot) ? And blue pin 3 (Cold)
The condenser mic is a Neumann kms105 not a sennheiser kms105😉
And I like your videos
Thanks🙏🏼
Cool cool,
Awesome explanation!
Awesome and thank you
Thanks Dave, that was brilliant that!
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You're a madman Dave! I love it! 😏🤘
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wow i was just talking about this last night over a beer/s... thanks for the video
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As always, another excellent video, Dave. You mentioned having first generation (1970's) AKG C-451's that would run on anything from 9 - 52 Volts DC phantom power. The wide range of power options allowed them to be used with field recorders or other battery operated devices or just any console that used a different voltage because there was no agreed upon standard back then. But one less common mic that many engineers are not familiar with is the AKG C-452 which used the same modular head/capsule system but it could _only_ run on 48 Volt phantom power because it was designed and sold shortly after 48 Volts became internationally standardized among manufacturers (1981?). Allegedly the 452 with its modified 48 volts only circuit has a lower noise floor than the 451 but I honestly don't know if that's true.
I remember the c452 maybe was the C452eb. Higher voltage also could help with max headroom.
@Phil Allison very interesting and thank you!
Great video Dave!
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Fantastic video.
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Not sure if anybody else mentioned it in the comments or maybe you followed up Dave but people often forget that if you are using a splitter box with out transformers but does have ground lifts for one or two of three splits phantom power should come from the split that the ground lift does not lift. When the ground gets lifted it breaks the phantom circuit.
this is absolutely correct phantom will not pass with the ground lifts also running phantom to a ground lifted split will not hurt anything
EXCELLENT video as always!
My only comment is that this only works IF everything is properly wired and undamaged. You did touch on what happens if a dynamic mic is in the mix and an unbalanced cable is used...BUT what about the possibility of damaging a console's input or the output on a piece of equipment with improperly wired cables, a damaged cable, or some other issue combined with phantom power? I've just been burned by this one too many times...especially when tying into someone else's gear. If it's all your gear, and all properly maintained, perfect! I still much prefer an active or transformer split for some isolation, but that's just me...
Phantom power should be safe for all pro gear regardless of being wired properly. It is limited by 6800 ohm resistors and gear designers should and almost always take into account the potential existence of phantom
Computers, semi pro, super cheap and home hifi gear? Not so much, that will often get cooked by ohantom
Great content as always Dave! Also suggest hiding some people in the comments
Hmmm, not sure who to hide but a good. We can absorb all perspectives with a smile
very helpful video👍
Thank you Mika!
Super interesting. Thankyou!
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Thanks Dave.
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Great Video. 😃👍♥️
Thank you Kevin!
Chiming in late. I've been watching your videos for several years off and on and they're all great and informative. Regarding this video on phantom supplies, there is one legit issue with not using phantom on inputs not requiring phantom. Such as wireless microphone receivers. As you mentioned, capacitors are used to block DC, protecting a mixer's active input circuitry as well as active devices connected. And in a perfect world this works well. However should a phantom powered microphone, wireless receiver (or any direct connected device with active as opposed to passive outputs) be unplugged or plugged in, the voltage change on the capacitors will cause the capacitors to briefly pass the voltage onto the internal circuitry of the mixer or other devices. This can cause a signal spike to be heard in the sound system as a pop. it can also damage microphones or active devices connected. Rule x; never plug or unplug microphones or devices into a mixer, stage box or sound system while phantom voltage is active. Make all connections first then activate phantom. And then there's the occasional bad mic cable causing loud pops in the sound.
Totally agree. Phantom applied to electronic inputs or outputs that are not designed for phantom is a common issue. Great points!
Awesome!
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I always love your videos. You always break stuff down and show it, instead of just talk about it. I appreciate that. I watch videos of yours on stuff I already know and still enjoy them and pick stuff up. Quick question though, I didn't think DC could pass through a transformer. Isn't that one of a transformers (isolation transformer) uses is to filter DC out?
Not sure of the specific part you are referring without re watching the vid, but...
There is a way to pass a DC voltage through a transforme and have it function correctly for ac by tying the centertaps of the primary and secondary together
if one leg of the DC was applied to both sides of the primary in relation to ground. The DC would show up on both sides of the secondary in relation to ground.
This is how phantom power can pass through transformers designed to pass phantom work
@@DaveRat Well I learned something new. I didn't think it was possible to pass DC. Thanks for the clarification. You're the man. Love your work and passion for audio. I share it.
Awesome! Thank Aaron!
Love you man!
Thank you!
High quality artistic skills!! Made my day! And I left CZcams more informed again.. thanks dave.. ps. Do you have a license?
Licence?
@@DaveRat for those guns! Been working out more in lockdown?
@@lerrynhawke3375 ha! Surfing everyday and made my day!
Great as alway .
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Hey Dave, super informative, I learned a lot. What about ribbon mics? I know it's more of a studio mic choice but I heard ribbons can be damaged by 48 volts. What's your experience with this and why does it damage a ribbon?
Ribbin mics are delicate and properly wired cables should not damage them. That said, one error can destroy them. Royer ribbons are phantom powered which protect the ribbons and they need phantom
Amazing
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Hey Dave, long-time fan and love the videos! Just to calm the nerves of those in our shop - with what you stated about the current being low, can I assume that if I have wireless mic receivers receiving phantom power that there's not much cause for concern? Thanks!
It won't hurt them, that said, some electronic outputs act strangely when they see phantom and don't sound correct
Hey!…you’re doing a good job
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Another home run Dave! Stuff we can use. I would assume that this is a moot point with linked digital consoles -- only one (or a stage box) can actually generate +48V.
Yes and no. Knowing how things work is not that important in optimum situations. And we all don't always deal with optimum
@@DaveRat I hope you didn't think I was being sarcastic, I really meant it was useful. I was just thinking about the digital realm and realizing that it's a different situation.
Thanks for all you do!
@@ToddWCorey1 no, all good and yes, with linked Digi, no need
Brilliant teaching of a subject that is obviously a part of you Dave . You could probably make brain surgery simple . Many thanks for what you do .
Honored and humbled thank you Rayviews!
Fantastic vid as usual Dave! Would love to hear your recommendations for study material regarding Power in the live environment. I know i'm not up to scratch on power, and with Universities putting out more engineers, I feel like power is the least understood part of this job. Hope you're in good health! ALSO WHO PUTS SUB ON THE OUTRO OF THE VIDEO?
I don't have good reference for live event power, definitely would be a good thing to find. Lots of stuff to know as well as conflicting regulations depending on country and portable versus fixed wiring.
Cool cool! 👍
Yes, cool cool! 👍
Great video Dave ...often contemplated these things. Do you subscribe to having phantom both ends of the snake then for voltage stabilities sake and have you ever found a change in practical sound from any condenser that has a phantom fluctuate from 48v to as low as you’ve measured.
The one thing I’ve missed is your opinion on what some of these experiments show you about the quality of the sound the different environments make. Was especially interested in your cascading channel analogue vs digital mixer experiments ...there were some raised eyebrows but nothing on the audio aesthetics. Nice one for the videos mate ...what else does one do when there’s nothing to mix
Cool cool. Having the added phantom voltage should at best, just offer slightly more headroom as well as redundancy. The main point is that it does not hurt anything. And ever so slightly could help.
Thanks Dave! Great video! I have only one question, if you would want to create 96V by running two consoles in series (20:30), how would you do it? would you just revers pins 1 and 2 on one console, or am I missing something? Thanks
It would be tough or not easily possible. You would connect pins 2 and 3 or pin 2 or 3 to the ground pin 1 of the other console and then, if at least one console was battery powered or not grounded in any way, you could see 96 volts between the pin 1 of console 1 and puns 2 and 3 of console 2.
Basically you would need to wire the phantom powers in series.
But if the pin 1 grounds of both consoles were referenced to each other then the 2nd console would just short the 1st console phantom to ground.
That would not hurt anything but you would just get 48v
Great explanation (as always on this channel)! I have one question though: If we have phantom power switched on at house and monitor consoles and the two consoles do not share the exact same ground (on the AC side, i.e. 120V or 230V depending on where you are); are maybe plugged into power outlets from different distribution boxes. In that case, we'd have some steady current on the (XLR) cables connecting the two consoles, specifically the ground wires, i.e., pin 1? To level out the difference in ground potential. Isn't this dangerous to the very thin mic cables?
Whether you supply phantom power or not the grounds of both consoles are connected together via the XLR lines unless specifically lifted. So any ground differential potentials that exist will exist regardless of whether phantom power is applied from one console both consoles or neither console
Can remember messing with some awful red plastic mic and a 9v battery as a kid in the 80's. Click click. Still plugging things into each other with not much idea of the maths behind it all 😊 and breaking many 😂
Great episode 👏 what would happen if both desks had phantom power on but one desk had phase reverse on ?
That's an interesting question. Since phantom power is 48 volts on both pins two and three and a polarity reverse only switches to with three polarity reverse makes no impact on phantom power.
There are several ways to reverse polarity either by swapping pin 2 and 3 or as consoles normally do after the line is unbalanced putting a polarity reverse opamp or circuit there.
Either way phantom shows up on both pin 2 and 3
If you have the time check out my videos on phantom power you may find them interesting I did one specifically on powering mics with multiple consoles
I wonder if there is any microphone response difference if 3 or more consoles drag down the voltage enough?
Any pro OB set up I've seen always used an active 3rd split anyway.
Would having 3 phantom switches on 1channel triple the current then?
3 should triple the current assuming you have a splitter that passes phantom
Dave, could you do a comparison between active and passive DI boxes? We use both and can't seem to tell a huge difference on the different instruments we use them on. And also, maybe compare against an instrument amp XLR direct out? Thanks!
I will ponder some DI box demos
If you wanted to go from one mic into Y split cable and then onto 2 inputs of the same same mixer ( double patch type thing)
Would it be the same as the 2 mixer set up?
As I have often thought if doing this one apply 48V to one of the inputs.
Yes, I would supply phantom from both and or all console inputs
Hi Dave. Thanks for the video! I do not fully understand how everything (phantom)power works, so I have one question.
When connecting the two consoles, why doesn’t the phantom power of console 1 hurt the pre amps from console 2? If I am correct, the cables are directly attached to both consoles. Does the XLR split prevent that from happening, or is it completely fine for the pre amps to receive +48 from the other console?
Thanks in advance!
All consoles and most if not all mics are designed such that phantom power will not hurt them. Also, phantom power, is very very low power, typically way less than .5 watts per leg. For comparison, a USB -C cable can deliver up to 100W. So USB-C can be 200 x as powerful and damaging as phantom power. Even though phantom is 48v, it is severely current limited so as soon as it sees even the slightest load, it drops in voltage very quickly.
It would take a few weeks to charge you phone with phantom power
Hey Dave, what is the frequency sweep you use on you intro / outros? Extremely nice for a quick Full range to Sub balance method. It's 4 times faster to just load a video from you before I get started on a session than to open a project setup just for monitor balancing. I bet that's not the compliment you were expecting out of this video, but it occurs to me you might could make a video based around giving the community a common reference point for dialing in drive rack based monitor systems. Although I wield a 7.1 Mastering system, a mono tone set followed by a stereo tone set could help those who either do not have hardware on hand or the know-how to setup a DAW project to do that. I mostly use my system for watching Blu-rays and Prime, sad kinda, but also blows every public movie theater away, also real content helps to hear/feel how closely the system represents other systems my content will play on.
Very cool. The sub outro tine actually comes from a subwoofer test tone sequence I use for testing subwoofers. On the paid members side there is an extended video as well as a link to a wave file.
It is 20hz to 100hz
Excellent vid! Does splitting a microphone signal with one of those Y-cables, if connected to both mixers, cause any degradation of sound quality?
It should not and is easy to test, just listen or measure the output of one console while plugging and unplugging the other console. Typically a console input will be like 10,000 ohms or so and a mic output will be 200 ohms or so. So, you can drive several consoles with very minimal impact on the mic output level and loading of the mic.
hi Dave - thanks for the video. Quick question--when you pass the phantom thru a splitter snake that has transformers on it where you can lift the grounds and all--how does that affect the consoles which deliver phantom? for example, I run a couple different splitters--whirlwind and ramlatch splitters and my to-console splits are 1 direct and 2 isolated. I tend to isolate the house desk from the monitor desk feed and make monitors run phantom. But on occasion, which I haven't been able to figure out, I have to apply phantom from the house desk in order to get a direct box to see power. If my house feed is isolated - that shouldn't work or be needed...but it does. Any thoughts on what is happening here within the transformers or the splits that I am not understanding? I feel like I am missing something obvious..been doing this 40 years but this when it happens (and it is not often) it baffles me. I've tried to figure it out - it isn't only on one llne/channel or with one direct box or from one channel on the split where a wire might be crossed. Any suggestions how to figure this out or track it down? Everything works so I have been hesitant to argue with it - but am I missing something here? Please tell me I am not getting senile.. :) thx!
A transformer iso or split that has centertaps tied together on the inputs and outputs(s) will pass phantom.
@@DaveRat AHAH!! YES...ok thanks Dave. Sorry if this was a stupid question. Appreciate your response.
We just bought a set of drum microphones for a church. Is it safe to use another mixer just for the drum mics for 48v (both the dynamic and OH condenser mics) and use a send for the snake, traveling to the main house console?
Otherwise, I'll have to check the wirings of my dynamic mics and xlr cables one by one if we'll gonna be using a single console where both the drum mics, singers instruments will be plugged in.
Thanks in advance Dave! Your videos are always helpful!
Yes, all good with using a drum sub mixer and also, with the SoundTools XLR Sniffer/Sender (I designed it) you can test all your lines in a few minutes or less. Just turn on phantom and plug in the sniffer to each channel on the snake and it will tell ya good or no good. Probably worth having one.
czcams.com/video/bG77DLOTPsQ/video.html
22:40 Nice sweep of 86hz - 21hz and back at the end... its sound lower but the meter no longer measures. lol
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My computer audio has a 400W JBL sub on it. That sweep really shakes the house!
@@petetrott7568 I dont try it...i have a prof amp rack in my leaving room aprox 6 channels total 3,8 kw, but i have only one 230v phase of 16 amp's...cant do not test at full power. Here small test xd (Notice: the plops in sound are from the camera that cant handeling the sound pressure) czcams.com/video/UeJemn-PvZg/video.html
@@petetrott7568 so cool!
@@JohnvL 👍
Thank you Dave , I wonted to connect a 15 too 48 source I'm afraid I hope this is what your covering.
👍🤙
Is the ethercon breakout boxes wired T568A or T568B? Would this have something to do with why my ethercon system is not lining up 1 for 1? I wired my whole system T568B.
Shoot me an email at daveratsound@gmail.com and will help ya sort.
I bought a used OM7 from Rat Sound on eBay a couple years back. I've never been really happy with it. Maybe this is why!
Don't understand how a video on phantom using my personal test mics relates but if there is an issue with a mic you bought from rat, will gladly assist
@@DaveRat Hey Dave! I'm mostly joking here. I did buy an OM7 from y'all a while back. It's been a go-to drum vocal on a festival patch or lead vocal on a super loud stage. It's worked well enough, but I have never been 100% happy with it. I'm not suggesting it's your fault. Just a little tongue and cheeky you know? If you are ever in Denver hit up Mountain West Production Group. We'd love to hang out.
Cool cool, yeah, the big advantage of the om7 is with loud stages and singers that stay on the mic gets you the up close and personal voice in loud roons.
That said, many singers and stages are not in the realm
Phantom can be nasty if fed through Patch bays, the spikes caused by repatching can DAMAGE stuff including SPEAKERS & your audiences Hearing : )
He actually covered that part. In 1/4” patchbays, you can short pins to ground when plugging/unplugging. This causes the mic diaphragm To POP and clip the input of the console
Yes, patch bays and phantom are like a mine field.
Yes, and the detail of 1/4" with phantom in a patchbay is a great point.
Question please. I have a splitter that itself provides phantom for each channel if needed. In your scenario above, I am assuming that a voltage drop occurs because I have two consoles FOH and monitor not turned on for phantom as I have been relying solely on the splitter source for the power. I don't use enough condensers that I think it would cause too far a drop, but with that scenario, should I be keeping it as I have it or should I have phantom on both channels from both boards as well as the phantom on the splitter. My boards allow phantom to be selected for each channel needed vs powering the entire board. Thanks for the explanation, it makes sense, I just never gave it a thought before 🙂
If your splitter supplies phantom, just use that. The sitter will most surely block the phantom from the consoles so console phantom is not needed
I'm a total novice about this topic but I have a question about using drum mics. The typical kit comes with various dynamic mics for close mics on the drum and two overhead pencil condenser mics that require phantom power. Obviously, when using one mixer, you have to turn on the phantom power for the condenser mics but that means it's on for the dynamic mics too. It sounds like you're saying this is ok as long as the cables are good. I was wondering this is the normal, expected way to use these drum mic kits. I haven't found any source that addresses this specific issue. Thank you.
Mosicers allow 6urn8ng on phantom on each channel seperately. That said, if phantom was dangerous to any mic, that would be a huge problem.
Phantom is safe for all mics with properly wired cables and phantom is so low power almost no mics can be damaged by it though there are some older ribbon mics that can be damaged by wind, dropping, blowing into them and potentially miswired phantom.
Don't worry, you won't ever encounter these or any mic that can be damaged by phantom unless if you break into the vintage mic section of a recording studio.
I can see that the cats stagebox seems to pass Phantom power. I wanted to know if that same stagebox would be able to pass phantom power across a cat6 cable going into the snake?
Yes, it will pass phantom and each channel can be individually phantom powered, works just like a 4 channel snake with disconnects.
In a large venue where FOH and Monitor World might be on a different Phase/Leg as far as their power source will this cause an issue?
Typically a differing phase is not an issue. Its when the ground for mons and FOH are different and not tied back to the same place that issues arise. Since neutral is tied to ground somewhere in most, if not all, power systems, loads on the neutral can drag it off of zero volts and possibly drag the ground off of zero volts. Or if there is gear that somehow causes the ground to not be zero volts, that can cause issues if the ground at FOH is differing in voltage to the ground at mons. With digital snakes, this is less of an issue and usually a non issue as long as the ground offset voltages are small. With analog snakes and interconnects, even very small offsets in voltage between the ground at FOH and mons can cause hum and buzz issues. Large ground voltage offsets can be dangerous or deadly.
Cool cool...
Cool cool cool! Thank you!
Is there any way to remove phantom power from the output, I have a mixer that has all phantom on or all phantom off?
If I run phantom into a passive DI box, will it damage the input device?
A couple of 100uf capacitors, 1 each on pin 2 and 3 will remove 0hantom. But phantom won't hurt a passive di
Thanks for the vid, could you help me a bit?
I have an effect pedal with constant 24V phantom power, will it make any harm if i use it in a chain like this:
Condenser mic --> external power supply with phantom power 48V --> effect pedal with constant 24V --> audio interface with turned off phantom power --> pc
Phantom power into balanced outputs should not hurt anything. I have seen some outputs don't like it and either distort or offer reduced output levels when phantom is went to them.
Just try it. If it works and sounds ok, roll with it
Thank you so much for sharing your talents and experience with all of us.
I have a question. I want to utilize 2 AT4033 large diaphragm condenser mics in my acoustic trio. I also love the sound of our Meinl slap top cajon with passive pickups connected directly. Im told by percussion dealers that phantom power will damage it and our small Bose digital mixer doesnt have individual channel control of phantom power. How can I protect the cajon? Will the low Z output of any passive direct box isolate and serve the purpose? Do I need a specific device?
Thanks again!
Yes, the output of a direct box will block phantom. Or use and isolation transformer. Or make a special xlr cable that has 100uf capacitors on pin 2 and pin 3. Phantom won't go through a capacitor.
@@DaveRat Thank you so much! Your approach and egoless attitude are rare and so refreshing in this business. You should write a book or a series. I'm sure they'd be VALUABLE go to resources for all of us. Your knowledge and experience needs to be preserved.
Thank you!
@@tlb2732 thank you Tony and much appreciated!
Re one console loading down the phantom from the other, I’ve seen consoles that drag the voltage down to 24 volts. Basically the phantom switch chose between +48 and ground, likely for noise reasons.
Oh my