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I want to know if I can convert a 48V DC power adapter that I have at home to use it as phantom power for my condenser microphone.

I only want to add some sockets that can support a microphone.

Just wanted to know if it is possible at all.

JRE
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Amit Ray
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    Is it possible? -> yes – user253751 Mar 01 '19 at 02:30
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    I concur. It is possible. – K H Mar 01 '19 at 02:34
  • @immibis and @K H Thanks for the answer. Any idea what should be the current output min & max. – Amit Ray Mar 01 '19 at 02:37
  • @Amit Ray a very few mics I know of will draw close to 10mA, but the vast majority of single-capsule condenser mics won't draw more than 5mA. Which mic are you using? –  Mar 01 '19 at 06:25
  • I am using this https://www.amazon.in/MXL-Mics-770-Condenser-Microphone/dp/B0007NQH98/ref=sr_1_7?ie=UTF8&qid=1551428111&sr=8-7&keywords=microphone+condenser – Amit Ray Mar 01 '19 at 08:15
  • not all phantom power mics use 48V – Tony Stewart EE75 Mar 01 '19 at 13:13
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    @SunnyskyguyEE75, it's nearly all; certainly all mics sold today will be expecting 48V, including the microphone in question. Some older oddball ones may use something else, but it is so rare that no modern mixers/mic preamps would support it. – Nate S. Mar 07 '19 at 01:05
  • @NateStrickland Almost all, I should have quoted the veteran Yamaha Engineer who said " some manufacturers use lower voltages (24V or even 12V) to save costs." https://hub.yamaha.com/tools-of-the-trade-mixer-and-phantom-power/ – Tony Stewart EE75 Mar 07 '19 at 01:10
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    @SunnyskyguyEE75, on the mixer side, you're right -- I thought you were referring to the mics. Some mics can work as low as 12V, but some require 48V and all should tolerate 48V since it's by far the most common thing for mixers to supply. Any mic that did NOT work at 48V would be incompatible with the majority of audio equipment out there, and therefore would not sell, so no one does that even if it would be cheaper. – Nate S. Mar 07 '19 at 18:18
  • i agree......... – Tony Stewart EE75 Mar 07 '19 at 18:20
  • Thanks to all of you. I purchased the mic and its working fine even without Phantom power. – Amit Ray Mar 08 '19 at 08:47
  • @TonyStewartEE75 the ones that do not use 48V are pretty rare, typically tube mics with their own custom supplies or very specialist. – danmcb Jun 13 '23 at 12:44
  • the "veteran Yamaha engineer" seems to be a bit out of touch with reality. People switch 48V on and off all the time with the desk power on (but channel muted), and 12V mics etc are almost mythically rare. – danmcb Jun 13 '23 at 12:54
  • I wonder how it worked so fine without any phantom supply for the FET pre-amp yet has a C cell battery. @danmbc Perhaps he got a different dynamic mic. – Tony Stewart EE75 Jun 15 '23 at 11:15

1 Answers1

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Yes. But. All 48 V supplies are not created equal. Switching power supplies usually are a poor choice, due to merely industrial levels of noise control.

Here is some background information:

https://en.wikipedia.org/wiki/Phantom_power

AnalogKid
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  • I don't think switching power supplies are a problem per se. Most audio equipment manufactured in the last decade or so is using switching power supplies at this point. However, you're quite right that a random 48V supply out of the junk drawer probably wouldn't be appropriate -- A low noise supply, either linear or switching, would be needed. – Nate S. Mar 07 '19 at 01:01
  • @NateS. they are a problem unless they have very low noise. Much (semi or) pro gear that does not use much current will use a switcher with (say) +/-16.5V out and then a pair of linear regulators giving +/-15V. Given that the 48V on a mic connection is resistively mixed with the mic signal (typically 1-5mV) the noise requirements would be almost impossible to achieve (RMS noise in the sub-microvolts range). (In many cases when switchers are used they are chosen so that the noise is far above 20kHz.) – danmcb Jun 13 '23 at 12:43
  • Don't confuse noise on a scope with noise in your ear. – AnalogKid Jun 13 '23 at 13:33