Talk:Phantom power

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Contents 1 Standards 2 Rewrite 3 Origin 4 DI Box 5 "Dangers" of phantom power not true

[edit] Standards

I know that the phantom power standard (whatever that is) specifies 6.8k resistors between the 48 V supply and the (XLR) pins. As here:

http://www.uneeda-audio.com/phantom/phan03.gif

This could be specified, maybe with a circuit. It is not always adhered to, however.

Also, there is a "standard" for the mic load, which is 9k between pin 1 and the others, and 200 ohm between 2 and 3. However, I have no idea where this standard comes from and I am sure it is not widely used. Just what I was told to use. Maybe it is just a standard test load. But anyone who wants to search these and write about them should. - Omegatron 17:42, Mar 2, 2004 (UTC)

[edit] Rewrite

Major rewrite. To be done: add references to the IEC standard (EN 61938) and DIN 45596. Also if anyone can improve the style and/or add the usual Wiki cross-references, great. I'm kind of new at this. DSatz 13:46, May 8, 2005 (UTC)

[edit] Origin

Someone added the claim that Neumann (= Georg Neumann GmbH, Berlin) invented phantom powering in 1966. That is indeed the year of Neumann's first phantom-powered microphones (the KM 83, KM 84 and KM 85) according to Neumann's history chart (see http://www.neumann.com/infopool/download.php?Datei=docu0051.PDF) and other sources. It may well be that Neumann introduced 48-Volt phantom powering.

But the article also mentions a system used by French radio somewhat prior to this time, with 9 - 12 Volt phantom powering and a positive circuit ground. Nagra analog tape recorders, including my IV-S right ... here ... (stretching) ... supported this "negative phantom" powering system, which matched the positive ground power supply of the Nagra itself. To my knowledge the first studio microphones made for that system were the Schoeps CMT 2-- series (CMT 24, 25, etc.). I have a schematic for their circuit dated July, 1964, but the company says that the microphone itself was introduced only in 1965. I haven't been able to resolve that difference yet (Schoeps never kept such good historical records, unfortunately).

At any rate it seems clear that Neumann adapted this powering method to what eventually became its most popular form, but they didn't invent it. DSatz 22:13, 29 October 2005 (UTC)

I really think someone should look more closely into the origins of phantom. I personally own two phantom powered schoeps microphones that pre-dates the KM84.

Also, the sentences about a auxilliary 48 volt system at the norwegian broadcasting is as far as i can tell unfounded speculation from Neumann. The consoles in use there at that point was to a large degree built by Kongsberg Vaapenfabrikk( http://www.kongsberg.com/nor/kog/ ), the powersupplies might have been 48volts so the misunderstanding might come from there. And even though it is dark in the winter, i would suggest that normal 220Volt electricity where used for lighting purposes:-) They did however adapt the use of american cannon/xlr connectors early on togheter with the BBC, so the misunderstanding might stem from this. KM84 serial no. 34 is atleast a cannon equipped mic. belonging to the norwegian broadcasting company.

[edit] DI Box

This is mentioned near the beginning of the article, with no explanation as to what it is. I have a rough idea, but not really enough to add it to the article. Perhaps someone who knows more about this subject could do so? 82.32.46.112 22:06, 21 November 2005 (UTC)

DI box — Omegatron 20:51, 8 December 2006 (UTC)

[edit] "Dangers" of phantom power not true

The section on the danger of phantom power is untrue - the maximum current of 14mA is nowhere near enough to cause injury or death.

Shocks and electrocution from microphones are instead from faulty grounding and AC power wiring - the referenced story about a pastor being electrocuted involved faulty wiring on a water heater connected to the baptismal pool. —The preceding unsigned comment was added by 12.161.159.124 (talk) 02:43, 20 January 2007 (UTC).

agreed, the only mentions of phantom power i could find in the reference were saying that it probablly wasn't the cause! signal ground tied to a broken mains ground that rose up because of a fault is a far mroe likely explanation for a shock from a microphone.