View Full Version : Poor man's XLR to GH2 adapter


Bill Bruner
January 7th, 2013, 06:05 AM
Running a $75 used Audio Technica AT835 mic (sourced from eBay) directly into my GH2 with a $15 Hosa Low Z to High Z transformer (http://www.amazon.com/gp/product/B0002IAJ2O?tag=din0a-20) and a $5 Hosa GPM-467 3.5mm to 2.5mm adapter (http://www.amazon.com/Hosa-GPM-467-Analog-Audio-Adaptor/dp/B000QU3JN4). The windscreen is a $55 Olsen Mic Muff MM-21 (http://www.amazon.com/Windscreen-Technica-AT8035-AT835---OLSEN/dp/B00ABPK432). It works really well for my application (standups right in front of the camera for my vlog).

Connected to the GH3, I won't need the GPM-467 any more. A lot less expensive than Panasonic's $349 OEM solution (http://www.amazon.com/Panasonic-DMW-MS2-Shotgun-Microphone-DMC-GH3/dp/B00AFNA2LE) :)

https://lh5.googleusercontent.com/-6x2ziHgKUyQ/UOq2-ksrfPI/AAAAAAAAGXk/8i0Hrh9rLFw/s1149/P1010660.JPG

Bill
Hybrid Camera Revolution (http://hybridcamerarevolution.blogspot.com)

Adrian Frearson
January 7th, 2013, 07:39 AM
So the GH3 still has a little 2.5mm input? Damn, I was hoping that they had put in a real 3.5mm at least!
The little adapters are great for static set ups, like you'll be using, but they're a bit of a nightmare once you start moving around a lot.

Kevin McRoberts
January 7th, 2013, 09:35 AM
That photo is a GH2... the GH3 has a 3.5mm input. The GPM-467 he mentions is the model# of the 3.5-2.5 adapter

Bill Bruner
January 7th, 2013, 12:41 PM
Sorry for any confusion. Kevin is correct, that was a picture of the GH2. I will post a picture of the GH3 setup tonight or tomorrow.

Adrian Frearson
January 10th, 2013, 02:57 AM
Guess I should have read your post properly!

Bill Bruner
January 31st, 2013, 02:10 AM
Finally - here is a picture of the GH3 setup (no 3.5mm to 2.5mm adapter required :)):

http://lh3.googleusercontent.com/-oqrYrmiGzG4/UQoG3m6k9XI/AAAAAAAAGfc/-_BdDOmsx-Y/s1021/P1110865.JPG

Bruce Foreman
January 31st, 2013, 11:26 AM
Get that squirrel off your camera before it does what birds do on my new car!

Jase Tanner
January 31st, 2013, 01:38 PM
Bill

Curious to which squirrel er, mic you've got there.

Bill Bruner
January 31st, 2013, 03:43 PM
It is a used Audio Technica AT835 like this one (http://rover.ebay.com/rover/1/711-53200-19255-0/1?icep_ff3=2&pub=5575034783&toolid=10001&campid=5337235943&customid=&icep_item=251219971540&ipn=psmain&icep_vectorid=229466&kwid=902099&mtid=824&kw=lg) from eBay.
The "squirrel" is an Olsen MM-21 Mic Muff

Bill

Ron Fabienke
February 1st, 2013, 10:17 AM
I will be shooting first video job with the GH3 tomorrow, a behind the scenes & flavor of the event capture, for "his" editing into a future demo piece, of one of my friends in the video business putting on a large company event tomorrow night.

I have a DVMulti-rig setup that will hold a light as well as a small Sennheiser wireless receiver and a short Sennheiser super cardioid mic on a small isolation mount. Both will feed XLR into an also mounted Juiced Link DT454 mixer, which will feed the GH3 mic input with mixed stereo and override its AGC. I can monitor off of the mixer so my flip out LCD screen is not limited in its movement.

My question is when he edits this in FCPX will it allow him to work with the two channels "individually" for their levels.....that were recorded as stereo to the camera?

He wants a LAV on him and the good external cardioid mic for ambient sound and the only capture will be from my rig, no external recorders used.

I'm editing in Premiere and "think" any stereo track has to be worked with as a whole.

If the 2 channels can't be separated then if I am off shooting away from him I guess I will need to unplug the LAV input from the mixer for those shots.

Thanks much

Guy Smith
February 1st, 2013, 01:29 PM
Thanks for posting Bill, do you have any audio samples that you can share?

I've had noise issues with all but two mics – and both of them were low impedance (150 Ohms and 200 Ohms). Everything else (microphones, field mixers, wireless receivers) was 600 Ohms and noisy, so it seems to me that an adapter with a high output impedance would make things worse, not better.

Ron Fabienke
February 1st, 2013, 02:51 PM
I will be shooting first video job with the GH3 tomorrow, a behind the scenes & flavor of the event capture, for "his" editing into a future demo piece, of one of my friends in the video business putting on a large company event tomorrow night.

I have a DVMulti-rig setup that will hold a light as well as a small Sennheiser wireless receiver and a short Sennheiser super cardioid mic on a small isolation mount. Both will feed XLR into an also mounted Juiced Link DT454 mixer, which will feed the GH3 mic input with mixed stereo and override its AGC. I can monitor off of the mixer so my flip out LCD screen is not limited in its movement.

My question is when he edits this in FCPX will it allow him to work with the two channels "individually" for their levels.....that were recorded as stereo to the camera?

He wants a LAV on him and the good external cardioid mic for ambient sound and the only capture will be from my rig, no external recorders used.

I'm editing in Premiere and "think" any stereo track has to be worked with as a whole.

If the 2 channels can't be separated then if I am off shooting away from him I guess I will need to unplug the LAV input from the mixer for those shots.

Thanks much



I hope I haven't embarrassed myself with a dumb question above. But now I have to go to my local pro sound company and pick up a small 3.5mm male to male cable to run from the Juiced Link mixer to the 3.5mm input on the GH3. I have been assuming this is a stereo input? But I also know what "assume" can turn me into..... :) By chance is that a mono jack?

Bill Bruner
February 1st, 2013, 04:17 PM
...By chance is that a mono jack?...

It is a stereo input.

Bill Bruner
February 1st, 2013, 04:22 PM
Thanks for posting Bill, do you have any audio samples that you can share?

Sounds great through headphones on the GH3. I'll record something tonight.

I've had noise issues with all but two mics – and both of them were low impedance (150 Ohms and 200 Ohms). Everything else (microphones, field mixers, wireless receivers) was 600 Ohms and noisy, so it seems to me that an adapter with a high output impedance would make things worse, not better.

The input for the GH2/3 and most consumer devices is around 2500 Ohms, so a Low Z to High Z transformer is appropriate for this application.

Bill

Bill Bruner
February 4th, 2013, 06:04 AM
I finally had the opportunity to record a test of my eBay procured Audio Technica AT835 plugged into the Panasonic GH3 with a Hosa MIT-156 line matching transformer. In the video below, I compare the $75 AT835 to my $80 Azden SMX-10 consumer mic. It was no contest.

Audio Technica AT835 vs Azden SMX10 - straight into the Panasonic GH3 on Vimeo

I will have to do more testing, but the GH3's preamps sounded pretty darned good to me. Good enough for interview or B roll audio, and perhaps good enough for production audio.

More details on the blog (http://hybridcamerarevolution.blogspot.com/2013/02/audio-technica-at835-and-gh3-pro-mic-vs.html).

Hope this is helpful,

Bill
Hybrid Camera Revolution (http://hybridcamerarevolution.blogspot.com)

Guy Smith
February 5th, 2013, 01:00 PM
Thanks for providing the audio samples, Bill - very helpful! Your results are significantly better than what I got with my 8035. Still more hiss than I'd like, but it likely wouldn't be noticeable when used in situations with even a small amount of ambient sound.

Eric Lagerlof
February 10th, 2013, 12:49 AM
"I'm editing in Premiere and "think" any stereo track has to be worked with as a whole. If the 2 channels can't be separated then if I am off shooting away from him I guess I will need to unplug the LAV input from the mixer for those shots."


Ron, In Premiere, select the clip in the project manager, than go to: Clip>Audio>Breakout to Mono. You will get the original track with the stereo track and 2 completely mono tracks as well. If dragging a mono track onto the timeline doesn't work, (because the tracks might default to 'stereo' tracks, drag the mono tracks to the empty space below the audio tracks in the timeline window and new mono tracks will be created. They will be independent tracks so once they are aligned with the video select and right click all the tracks and 'link' them so they'll stay in sync.

Sorry if I'm posting a bit late...

Mark Rosenzweig
February 10th, 2013, 12:05 PM
Bill, I always find your thoughts useful.

In the case of the microphone demo, you are comparing a mono shotgun microphone to a stereo cardioid microphone. Of course the former is better-suited to a talking head video; the stereo cardioid is supposed to pick up ambient sound, the shotgun not. And that is what you hear - more ambience from the Azden. This has nothing to do with pro versus amateur or balanced versus unbalanced (as you know, the distances for this demo were short anyway). I am not arguing that the AT mic is worse or better, only that this was an apples-oranges comparison.

If you recorded a horn quintet, the stereo Azden would very likely provide better audio than the mono shotgun.

The key for good audio is more picking the right kind of mic and mic placement for the situation, not so much the quality of the mic (that matters too). In this case (of a talking head), a $29 unbalanced lavalier might have done even better than the shotgun.

Bill Bruner
February 10th, 2013, 11:20 PM
Thank you for the thoughtful comment, Mark. I have found your posts to be very helpful and informative as well.

I take your point about pickup pattern and stereo vs. mono, but the published specs tell the story for these two mics.

The Audio Technica's signal to noise ratio is 70dB, while the Azden's is 60.

The AT's frequency response is 40-20,000kHz, while the Azden's is 100-18,000 (you can hear the lack of bass from the Azden in the test).

As one might expect, the AT835's specs (http://www.audio-technica.com/cms/wired_mics/5820fd64ff477519/index.html) show a nice cardioid pickup pattern with minimal sidelobes and good rejection of noise from behind the camera. The frequency response chart is also very clean, with a smooth bass rolloff and flat response across the frequency range.

Because the Azden is a consumer mic, it is a challenge to find an illustration of the pickup pattern or a frequency chart, but Azden's specs (http://www.azdencorp.com/new/product.php?productid=93733) call it "uni-directional", so consumers should reasonably much expect better off-axis rejection of room noise.

I don't think I'd record music with it :)

Cheers,

Bill

Duane Adam
February 11th, 2013, 09:22 AM
I did my first sound test on the GH3 last night by running an audio signal into the mic input to simulate an external pre amp. Unless I'm missing something, there doesn't seem to be a way to set the input to line vs mic. To set workable levels I set the camera audio to 1 and controlled the input with the audio player.

A couple of observations. When you get anywhere near 0dbfs (to my ear it sound like -10-dbfs) there is a limiter that is triggered which kills dynamic range. Best settings seemed to be about 60% of max input or less which bypasses the limiter. Also, there is a noise gate that masks hissing. At first I though the GH3 had a dead quiet mic pre but it was just the noise gate cutting of the input when it didn't hear a signal. The GH3 input creates a lot of hiss. I doubt the signal to noise ratio is more than 60 and for me there's too much hiss to use the camera audio for any pro projects. If it had a quiet line stage you could use an external pre but with its current configuration that doesn't seem possible.

Alan Halfhill
February 15th, 2013, 04:45 PM
I have been using my Rode Video Mic Pro, Sennheiser Wireless plugged directly in to the camera. Also the JuicedLink DT 454. Here is my video tests. An Early Present, The GH3: It Sounds Real Good » FrugalFilmmakers.com (http://frugalfilmmakers.com/2012/12/13/an-early-present-the-gh3-it-sounds-real-good/)

Terry Wall
March 1st, 2013, 05:58 PM
Hey, Bill! I really like your rigging--and step-down configuration to get to 2.5mm, while minimizing noise. I think I'm going to replicate it. Hopefully, I can pick up a GH3 this Summer, and, like you, forego the GPM-467. Thanks for the tip!

TW

Bill Bruner
March 1st, 2013, 09:12 PM
Glad to be helpful, Terry. This is really turning out to be a good value for money setup, but the AT835 is a little long. I'm looking to sell it and buy a:

- $170 AT875R,

- $10 Denecke belt clip and

- $80 Denecke phantom power (http://rover.ebay.com/rover/1/711-53200-19255-0/1?icep_ff3=2&pub=5575034783&toolid=10001&campid=5337235943&customid=&icep_item=140921984369&ipn=psmain&icep_vectorid=229466&kwid=902099&mtid=824&kw=lg).

Pro quality mic with a balanced output and 48V phantom power for $260. Not bad :)

Cheers,

Bill
Hybrid Camera Revolution (http://hybridcamerarevolution.blogspot.com)

Terry Wall
March 1st, 2013, 09:50 PM
I already have the Sennheiser ME66 and 67 with the K6 capsule, so I'm good to go in that area! The '66' should work well as it's the shorter of the two.

Cheers,
Terry