Best phantom power voltage, or should I use battery powered?

[jplaforest]

Hi everyone, I am currently using a Zoom H6 which can output 12v, 24v, and 48v phantom power, and an Audio Technica AT803 lav which can run off a AA battery or 11-52v phantom power.

Since the recorder and mic can both work with 12, 24, and 48v phantom power, is either option better for either sound quality, battery life, or anything else? How about phantom vs AA battery?

Any help would be appreciated. Currently I split the difference and went with the 24v which sounds well and has no issues, but curious what the best practices would be.

According to the AT803 specs:

OPEN CIRCUIT SENSITIVITY Phantom: -44 dB (6.3 mV) re 1V at 1 Pa
Battery: -46 dB (5.0 mV) re 1V at 1 Pa

IMPEDANCE Phantom: 200 ohms
Battery: 270 ohms

MAXIMUM INPUT SOUND LEVEL Phantom: 135 dB SPL, 1 kHz at 1% T.H.D.
Battery: 121 dB SPL, 1 kHz at 1% T.H.D.

DYNAMIC RANGE (typical) Phantom: 107 dB, 1 kHz at Max SPL
Battery: 93 dB, 1 kHz at Max SPL

 

[ecc83]

Hi everyone, I am currently using a Zoom H6 which can output 12v, 24v, and 48v phantom power, and an Audio Technica AT803 lav which can run off a AA battery or 11-52v phantom power.

Since the recorder and mic can both work with 12, 24, and 48v phantom power, is either option better for either sound quality, battery life, or anything else? How about phantom vs AA battery?

Any help would be appreciated. Currently I split the difference and went with the 24v which sounds well and has no issues, but curious what the best practices would be.

According to the AT803 specs:

OPEN CIRCUIT SENSITIVITY Phantom: -44 dB (6.3 mV) re 1V at 1 Pa
Battery: -46 dB (5.0 mV) re 1V at 1 Pa

IMPEDANCE Phantom: 200 ohms
Battery: 270 ohms

MAXIMUM INPUT SOUND LEVEL Phantom: 135 dB SPL, 1 kHz at 1% T.H.D.
Battery: 121 dB SPL, 1 kHz at 1% T.H.D.

DYNAMIC RANGE (typical) Phantom: 107 dB, 1 kHz at Max SPL
Battery: 93 dB, 1 kHz at Max SPL

I would assume that the AT803 is a back electret capsule and so the supply voltage is only going to affect the internal amplifiers which is shown by the reduced headroom. 135dBSPL is unlikely to be approached but 121 dB could easily be found in front of even a quite modest guitar amplifier or close to a carnivorous drummer.

If battery life is an issue consider buying them from a large "industrial" outlet like CPC/Farnell who carry high power types not generally found on the High Street. You have to buy a minimum pack though.

Dave.

 

[rob aylestone]

48v is the standard, the lower voltages are just easier to produce. Upping the voltage lowers the current, which is also important. Headroom on the lower voltage supplies doesn't have to be compromised, it's down to design, but on a mic designed for 48v, but capable of operating on, say, 12v headroom and performance is usually reduced. Few mics have a 12v limit, because the higher voltage is so common. Some thing designed to run from 1.5v can easily be happy with 48v phantom, but I would not buy a piece of kit that could not provide 48v, which is, after all, the standard.

 

[ecc83]

I agree Rob, failure to provide the full 48V does tend to smack of cheapening down.

But power supply issues are complicated these days due to the increasing use of DC-DC converters which are now relatively cheap and give remarkably good performance in terms of regulation and noise. The use of such converters also make supply voltages less important, a mic for example might be perfectly happy on 24V or 48V because it simply converts the incoming power to what it needs. The result is that power sources need to be able to supply sufficient current because devices will draw the power they need almost irrespective of the supply voltage.

On equipment other than microphones I would like to see a world standard of 12 volts (cos of cars!) except for devices that need very high amounts of power* . My personal bête noir is the various laptop voltages and bas'td connector variations (have you ever tried to BUY a Dell power plug?) . How many PSUs have gone to landfill for the want of the right voltage or a buggered DC lead? Is that Green or what?

*But even here, big Mother ICE amps have internal DC-DC conveters.

Dave.

 

[jplaforest]

48v is the standard, the lower voltages are just easier to produce. Upping the voltage lowers the current, which is also important. Headroom on the lower voltage supplies doesn't have to be compromised, it's down to design, but on a mic designed for 48v, but capable of operating on, say, 12v headroom and performance is usually reduced. Few mics have a 12v limit, because the higher voltage is so common. Some thing designed to run from 1.5v can easily be happy with 48v phantom, but I would not buy a piece of kit that could not provide 48v, which is, after all, the standard.

Thanks Rob, I'll set the Zoom to 48v!