Nikon D7000 powered external mic output
I've just ordered an Audio-Technica Pro 24-CM Stereo microphone that I'm intending to use with my Nikon D7000 (which is due to arrive on Thursday, Dec. 6th!). Does anyone know if the Nikon D7000 external mic plug provides sufficient power for this mic without using the mic's battery (a 1.5V LR44 battery)?
Nikon's spec for their own ME-1 stereo microphone (which Nikon's website indicates is compatible with the D7000), receives its power from the camera, there is no internal power from the microphone itself. Obviously, the Nikon D7000 external mic plug does provide power for that mic.
According to the Audio-Technica manufacturer's website the Pro 24-CM power requirements are "2-10V DC plug-in power". I've seen reviews of this mic that indicated it's used on some Canon DSLR cameras and is powered by the camera's mic plug.
#1. "RE: Nikon D7000 powered external mic output" | In response to Reply # 0
After doing some additional research, I've found that the ME-1 microphone that Nikon sells receives its power from the hotshoe, not the mic jack. So.... I guess I'll stock up on some LR44 batteries for my Audio-Technica mic!
#2. "RE: Nikon D7000 powered external mic output" | In response to Reply # 1
You might be able to make your own cable. If the ME-1 can take power from the hotshoe then you could take any hotshoe-based accessory or extension cable and splice it to an appropriate DC plug for your mic.
Of course, you'll need to do some legwork first. Like determining which D7000 pins carry the voltage, what the voltage is (including polarity) and how much current is available. Measured voltage and pinout are likely to be Googled up from some DIY site. The available current capability is likely not floating around the web unless it is published by Nikon and it cannot simply be measured without risk to your D7k. However, my guess is that anything designed to be powered by LR44 batteries takes very little current or they'd go flat way too fast. The mic current may be spec'd or you can at least measure that. Probably sub-milli-amp. I'd risk such a light load. In any case, good design practice would imply Nikon have provided some sort of over-current protection.
But realise that is an assumption, not a given. So you do it at your own risk.
#3. "RE: Nikon D7000 powered external mic output" | In response to Reply # 0
I have read conflicting descriptions of that mic. B&H calls it s Dynamic Mic when it is clearly an Electret Condenser mic.
The D7000 does not supply voltage to the FET built-in reactance to voltage converter that changes a dynamically changing capacitance to a changing voltage. The electret mic element itself has a permanently charge on the element but the FET converter needs about 1.5volts DC between Drain and Source terminals which the D7000 does not provide. The current drawn is not much higher than the leakage current of the battery itself so a battery will last a long time. Higher voltages can be tolerated however and the results include higher output level.
You can make a power adapter for larger batteries if you to, by building a small circuit with a AAA cell or 2 in series for 3 volts.
2 metal film resistors(for low noise) any value between 2K and 18k
2 1-10mfd Electrolytic capacitors.
1 TRS 3.5 mm phone plug(stereo plug)
1-2 1.5 volt AAA or AA batteries
1 Battery holder
2 TRS jack(stereo phone jack 3.5 mm)
1 small plastic box to house the battery, resistors and jack
1 Short length TRS to TRS 3.5 mm plug to 3.5 mm plug jumper cable. The length depends on how far from the camera do you want the adapter box(shorter the better)
A. Mount both jacks in the plastic box.Label one of the jacks "Mic In" and other "Output"
B. Connect a jumper wire between the ground terminal of the two jacks.
C. Connect the capacitor's Positive wire to the Tip of Mic-In jack and the negative wire to the Output jack.
D. Repeat by adding the other capacitor's positive wire to the Ring connector of the Mic In jack.
E. Connect one lead of a resistor to the Tip connector of the Mic-In jack. This will be the FET Drain load, to develop the output voltage across the load resistor.
F. Connect the other resistor wire to the battery holder's Positive(+) terminal.
G. Connect the second resistor to the Ring connector of the Mic-In jack.
H. Connect the two loose ends of the resistors together and connect the positive wire of the battery holder to the junction of the two resistors.
I. Connect the negative battery holder wire to the wire that connects the two jack's grounds together(added in Step B).
For use, plus the mic cable into the Mic In jack which connects the battery. When not in use unplug the mic and no current will be drained from the battery. Connect the TRS to TRS jumper cable into the Camera Mic in and the adapter box Output jack and it will be ready to work. Mount a strip of Velcro on the camera strap and glue the hook mating surface Velcro to the back of the adapter box for easy use or removal.
St Petersburg Russia
Visit my Nikonians gallery.
#4. "RE: Nikon D7000 powered external mic output" | In response to Reply # 3
I received the Audio Technica Pro 24-CM microphone and my new Nikon D7000 camera (Yea!). Tried the mic initially with an LR44 battery installed in the mic, and it worked properly. I've now mounted the mic, removed the battery from the mic itself and used the camera's mic jack. Again, the mic works well with its power derived from the camera itself.
Just from an initial, admittedly limited observation, I think the quality of the sound recorded with the mic using the camera's mic jack for power is somewhat better than when the LR44 battery was used to power the mic.
#5. "RE: Nikon D7000 powered external mic output" | In response to Reply # 1
>After doing some additional research, I've found that the
>ME-1 microphone that Nikon sells receives its power from the
>hotshoe, not the mic jack. So.... I guess I'll stock up on
>some LR44 batteries for my Audio-Technica mic!
Can't! No contact on the ME-1 hot shoe attachment. Comes from the jack. Have used the ME-1 off camera with an extension. Works well.
Blue Springs, MO
#6. "RE: Nikon D7000 powered external mic output" | In response to Reply # 4
There's something VERY strange about this because, as Stan said, the D7000 does ***NOT*** have the ability to supply power to an external microphone. FWIW, nor does any of Nikon's other video-capable cameras.
My STRONG advice is to rely upon the microphone's battery as any other apparent power source could easily disappear.
OK, so the ME-1 specification DEFINITELY indicates that it is an electret mic. whose power comes from the camera.
I have just measured a +2.5VDC bias on each of the mic. inputs of my D4, so an Electret mic. CAN be powered reliably by, at least some, Nikon bodies...
Stan: Everything seems to point to the fact that we were both WRONG!
James: I now believe that you CAN rely on powering the mic. from the camera.
Please accept my apologies.
#7. "RE: Nikon D7000 powered external mic output" | In response to Reply # 6
Sorry about the missinformation. I was going by two published spec sheets for the camera that says bias was not available. I modified my D90 the second week I had it to have a mic jack and to it did have the bias naturally since it had an internal mic electret mic but the bias was low so I increased it to the jack I installed to 5 volts. I used mine with non-electret mics so had to be sure there were DC blocking caps in-line with the mic element.
I guess it goes to to prove that you need to measure everything and not go by spec sheets.
St Petersburg Russia
Visit my Nikonians gallery.
#8. "RE: Nikon D7000 powered external mic output" | In response to Reply # 7
>I guess it goes to to prove that you need to measure
>everything and not go by spec sheets.
My wife complains I don't always read the doco. It's the engineer in me. I maintain that by reading the spec sheets you will only ever discover features that were intended - not the other nifty tricks & features they failed to document! That said, reading the manual is often useful for self assessment. Just like checking the answers in the back of your math textbook to assess how well you went!
Next I need to scurry off and check the floating DC on my D7k inputs. Love this forum for prodding my grey matter!
#9. "RE: Nikon D7000 powered external mic output" | In response to Reply # 8
Stan & Pete,
On Friday night last (12/07) I used my Audio Technica Pro 24-CM mic to record the audio for a choir performance at the school my grandson attends. The quality of the recording, while certainly not suitable for a professional video, was quite satisfactory and much better than the internal mic of the D7000.
The Nikon D7000 is obviously a fairly complex camera, and I'm still learning some of the settings for video (I only received the camera the day before the choir performance). So, some of the video I recorded wasn't quite as good as I wished. I had apparently fumbled the focus as I tried to adjust the subject coverage and, as a result, had some soft focus in the last part of the video.
I really am mostly a still photo person, and I'd expect to use the video capability of my D7000 only on a limited basis. It's still a very nice capability to possess on a camera that is very exciting to use!
#10. "RE: Nikon D7000 powered external mic output" | In response to Reply # 9
Have you spent time reading the many good posts in the Digital Video forum. If not, then I suggest that you should do so.
I wish you good luck with your video experiments, but I feel the necessity to offer a few words of WARNING:
Experimenting with DSLR video should be regarded as a highly addictive pursuit! A great many of us freely admit to suffering from NAS. That in itself can become pretty costly, but NAS becomes only a small part of the overall "problem" as you become hooked on video! Getting hooked is very easy after you see some good results early on - and then start thinking about improving the audio to match the visuals that you achieved. Then you wonder what it would take to improve the visuals..........
DSLR video can become VERY expensive (but great fun)!
Once again, good luck.
#11. "RE: Nikon D7000 powered external mic output" | In response to Reply # 10
Thanks for your advice and words of warning! I'll check out the Digital Video forum for some additional information.
I wish that I'd had my D7000 recently when I went to a 75th anniversary celebration at the Amerind Foundation in Southern Arizona. One of the events was a dance performance by members of the Hopi tribe from the First Mesa. I was using my Nikon D90 to record the dance, and the results were only so-so.
It's obvious that DSLR video could easily become addictive...
#12. "RE: Nikon D7000 powered external mic output" | In response to Reply # 11
The mic in the camera is not bad but it lives in an unfavorable acoustic environment. Being back where a camera is optimally positioned for image capture, puts the audio capture in a terrible position for optimum quality.
You are going to have to think of two different systems and optimize each. Getting the cheapest mic out there, close and in a primary direct sound field with limited reflected sound or in reverberant fields will reveal that the built-in mic is better than you think. Both the external mic and built in mic are suffering from high ratios of indirect sound to direct sound. If it is a fixed performance where the sources are set, mount a mic or one of the several miniature digital recorders in close proximity to the source and mix the field sound back into the video in post processing.
You can also ask for a house mixer feed which would be the PA mix of the mics on stage. In each of these cases, reducing the ratio of reflected to direct sound will make a world of difference. A $1 electret mic element close in will sound better than a $5000 mic bathed in a sea of reflected and delayed sound.
Another issue to consider is sync between sound and visuals. The image seen in playback is seen with the optical magnification of the longer lens so distance presents no delay in imagine(light is essentially instantaneous) But sound travels very slowly in air, about 1100 feet per second so even 30 or 40 feet away from the source will present enough delay between the image and sound to have human listeners disturbed by it. You can add delay, or slip the video but the best way is to capture the sound close to the source so it solves the problem of syncing sound to picture. So two big problems are solved by using remote mics near the source, without regard to the overall quality of any particular mic.
Any mic in a great acoustic space will sound better than the best mics in a bad space(one filled with stronger reflected sound and reverberant field) just like any camera and lens in a great light situation will be better than terrible lighting with the best cameras. It is just as dramatic a difference with sound as with light.
St Petersburg Russia
Visit my Nikonians gallery.