Topic: Powering at853s

[hoyt]

hoyt;

i think you're still not understanding the difference between the SP "battery pack" voltage and phantom power voltage.  the AT853 works fine with 9 to 52V phantom power. actually AT853 works BEST with high phantom power. the dynamic range is increased, max SPL is definitely increased by supplying phantom power rather than battery power.

phantom power is applied to a balanced connection. a simple mini-plug (unbalanced) will not work for phantom power.

marc

If you're supplying phantom power from an mp2 to a pair of sp at853's (ended in a mini plug > xlr converter), is this not phantom power?

About how long does it usually take for sound pro to return calls about questions?  I called last night and spoke to a woman who took down my info and said a tech would call me back.  I figured she meant some time today, but it's just a question, so I'm sure it's low on their priority of things to do.

Thanks for all the info and keeping me from potentially frying my cheap-ass mics!  

--hoyt

[leegeddy]

hoyt;

i think you're still not understanding the difference between the SP "battery pack" voltage and phantom power voltage.  the AT853 works fine with 9 to 52V phantom power. actually AT853 works BEST with high phantom power. the dynamic range is increased, max SPL is definitely increased by supplying phantom power rather than battery power.

phantom power is applied to a balanced connection. a simple mini-plug (unbalanced) will not work for phantom power.

marc

If you're supplying phantom power from an mp2 to a pair of sp at853's (ended in a mini plug > xlr converter), is this not phantom power?

About how long does it usually take for sound pro to return calls about questions?  I called last night and spoke to a woman who took down my info and said a tech would call me back.  I figured she meant some time today, but it's just a question, so I'm sure it's low on their priority of things to do.

Thanks for all the info and keeping me from potentially frying my cheap-ass mics!  

--hoyt

according to SoundDevice............

Phantom Basics
"Phantom powering" is a method of providing power to microphones by applying a voltage to the same wires that carry the audio signals. Phantom power can be generated from mixing consoles, mic preamplifiers, or in-line phantom power supplies. All of Sound Devices microphone inputs supply phantom power.

In general, phantom voltages are used to power electronics within condenser microphones. Condenser microphones require power for various parts of their operation, including impedance converters, preamplifier circuitry and, in some cases, to polarized microphone capsules. Phantom is usually a DC voltage ranging from 12 to 48 volts. Microphones draw current from this voltage based on their needs.

Balanced microphone interconnections have two signal conductors relative to a ground conductor. With XLR-3 connectors, pin-2 and pin-3 are the signal conductors and pin-1 is the ground conductor. The definition of phantom power is an equal voltage applied to pin-2 and pin-3 with respect to pin-1. To verify that a mixer or preamplifier provides phantom power, voltage measurements taken between pin-2 and pin-1, and pin-3 and pin-1 will read identical levels. No voltage is present between pin-2 and pin-3. Popular phantom voltages are 12 V, 15 V, 18 V, 24 V, and 48 V. 48 volt phantom is the most common and many microphones require 48 V for proper operation. New specifications from the AES outline five specifications for phantom voltages and current levels - P12L, P12, P24, P48, and P48H.

i'm not familiar (yet) with the SP models of AT853, but a buddy of mine sent his to me for modification.  i'm going to take a look at how SP unbalanced the mini-plug end.  i'm assuming they just used the HOT leads from the L and R mics to the Tip/Ring, respectively on the miniplug and simply grounded the Return leads to ground.

as for your (mini plug > XLR converter), i don't think it's going to work, because you NEED a balanced connection per the descriptions above to have the ability to supply phantom power to your mics.  your setup is unbalanced at the miniplug end which can not be re-balanced by simply using XLR converters.

i'll let you know how the SP AT853 mod goes and pass along the results.

marc

[hoyt]

... i'm not familiar (yet) with the SP models of AT853, but a buddy of mine sent his to me for modification.  i'm going to take a look at how SP unbalanced the mini-plug end.  i'm assuming they just used the HOT leads from the L and R mics to the Tip/Ring, respectively on the miniplug and simply grounded the Return leads to ground.

as for your (mini plug > XLR converter), i don't think it's going to work, because you NEED a balanced connection per the descriptions above to have the ability to supply phantom power to your mics.  your setup is unbalanced at the miniplug end which can not be re-balanced by simply using XLR converters.

i'll let you know how the SP AT853 mod goes and pass along the results.

marc

Hmmm.  Nice info.  I'll see what the tech knows about how the mini is built when I speak to sound pro.

Thanks!  (definitely a +t for marc!!)

--hoyt

[hoyt]

Just got off the phone with a tech from Sound Pro.  Very nice guy.  He said they have tested their at853's with upto 18 volts of phatom power without fying them.  

They now offer those mics on their page with a new $100 add on package to power off of phantom power between 9-52v or off of the battery pack.  

Here's the info from their site on the new package you can order them with:

Option 2: Add the Phantom power adapter kit. This will allow you to use the mics with "plug in power", a battery module (as in option 1) or with 9-52v Phantom power which is available on many professional mixers, mic preamps and recorders. When powered with Phantom power, the dynamic range and maximum SPL (sound pressure level) are increased even further (see specs below). The phantom power kit includes two phantom power adapters (Samson PM-4) and two high quality gold plated cable adapters as shown in the picture below.

Specifications:


Signal To Noise Ratio: 67 dB, 1 kHz at 1 Pa
Dynamic Range: 83dB without battery module, 98dB with battery module, 111dB with Phantom power kit
Frequency Response: Omni-Directional 20-20,000 Hz all others 30 - 20,000 Hz
Open Circuit Sensitivity: -43 dB (5.6 mV) re 1V at 1 Pa
Maximum Input Sound Level: 110 dB SPL, 1 kHz at 1% T.H.D. (125dB when powered by our battery module, 138dB with Phantom power kit)



What the tech told me is that I can modify them with a phantom power adaptor and then run it off of that 9-52v of phantom power.  The power adaptor was the Samson PM4 (sam-pm4).  $29.99 on their site.  For the modification he said- red > 2 pin, yellow > 3 pin, and then ground.  I'll give this a shot next weekend hopefully.

--hoyt

[Sean Gallemore]

yeah, and now the price is getting close to the stock AT853 mics

[drewloo]

Just got off the phone with a tech from Sound Pro.  Very nice guy.  He said they have tested their at853's with upto 18 volts of phatom power without fying them.  
--hoyt

I know this is an old thread but I was thinking about trying to power some AT853RX's via the 15v of phantom from a SD MP-2 without the AT power modules.  Some seem to think it's OK while others don't.  Has anyone successfully done this yet? 

[Javier Cinakowski]

I wouldn't worry about the 15v as much as I would worry about the impedance.  I am not sure but I think the impedance is different for electrets compared to 48v condensors.

[drewloo]

I wouldn't worry about the 15v as much as I would worry about the impedance.  I am not sure but I think the impedance is different for electrets compared to 48v condensors.

Thanks for the reply.  I'm honestly pretty clueless when it comes to ohms and impedance. 

=============================
OK, the AT spec sheet says the 853s are rated at 200 ohms, 1000 ohms without power module.

The mp-2 spec sheet says it's transformer balanced 2000 ohm input impedance.

Can any kind soul tell me if this info means anything, and if so, what?  thanks!

[Church-Audio]

Depends, you probably have the Sound Pro's at853s, in which case I would not power them with phantom power.  If you had the at853r's (the ones direct from Audio Technica) they terminate in XLR connectors and are supposed to be powered by phantom power...  

Keep the battery box, just make sure you have the settings right

You can not directly power the 853 with phantom power you will blow up the mics. The ones with the XLR connector on one end have electronics inside them to reduce the phantom supply to 10 volts and also to act as an impedance converter. Its also not true that using phantom power increases the spl of the microphone. Actually the difference is because your using a preamp with more dynamic range, and this is not a product of bias voltage. The difference between 5 volts and 10 volts is a distortion percentage of only 1%. So if your running the mics from a 5 volt supply and then switch to a 10 volt supply you will not notice any increase in SPL handling of the mic it self.

[drewloo]

Depends, you probably have the Sound Pro's at853s, in which case I would not power them with phantom power.  If you had the at853r's (the ones direct from Audio Technica) they terminate in XLR connectors and are supposed to be powered by phantom power...  

Keep the battery box, just make sure you have the settings right

You can not directly power the 853 with phantom power you will blow up the mics. The ones with the XLR connector on one end have electronics inside them to reduce the phantom supply to 10 volts and also to act as an impedance converter. Its also not true that using phantom power increases the spl of the microphone. Actually the difference is because your using a preamp with more dynamic range, and this is not a product of bias voltage. The difference between 5 volts and 10 volts is a distortion percentage of only 1%. So if your running the mics from a 5 volt supply and then switch to a 10 volt supply you will not notice any increase in SPL handling of the mic it self.

Chris, do you mean 48V phantom power or any phantom power at all?  My idea was to set the mp-2 to 15 volt phantom power (it can be switched between 15v and 48v) and hopefully I could get those big arse power modules out of the equation.  I guess I should open up a power module and measure it to see what voltage it's actually sending...     thanks, +t    BTW, my other thought was to have some sort of cable built that would drop the voltage a few volts from say 15v to 9v, but wanted to ask about strait 15v first.

[Javier Cinakowski]

15v might not fry the mics, but it still not going to be the right impedance.

[drewloo]

15v might not fry the mics, but it still not going to be the right impedance.

gotcha.   Ah, well...thought I might have had a good idea there for a sec.      Guess I'll stick to the battery box route then.    thanks, +t

[Church-Audio]

15v might not fry the mics, but it still not going to be the right impedance.

gotcha.   Ah, well...thought I might have had a good idea there for a sec.      Guess I'll stick to the battery box route then.    thanks, +t

Do not use phantom power of any kind on these mics with out making an adaptor. You will blow them up with 12 volts of real phantom power.

[SmokinJoe]

Just to throw another log of confusion on the fire...

I have AT-853's aka SP-SPSM-6 with SP's battery box which takes a little 12V A21/A23 battery.  I've put my voltmeter on the mic side of the battery box, and it puts out exactly what the battery is, no 9v stepdown.  If I buy a new battery which will run a little high (like maybe 12.5vdc) that's seems to be what is going to the mic.  No problems yet...  Whether 12 is OK, and 15 will fry... it's hard do say.

Joe

[nameloc01]

the 853 are wired from SP to use a standard 9vt BB. these mics cab be modded by SP with either the individual power modules or the special (SP) only XLR jacks that also step down a standard 48 vt phantom power supply, apparently these xlr jacks have some componenets in them that allow this to happen.i am sending mine back next week to have this mod done,and i am going to order the battery powered denecke ps-2 phantom power supply.
chris at SP told me,48 vt would most defintely fry the mics,no question about it.the mod and the denecke will add more abiltity to handle higher sound pressure levels.
if you go to their website and loom under the detailed specs for these mics, it will give yuou all of the info you need,and what spls each power option will give you. the AT power modules are the best available.