Pro shotgun mic for GH1

M

Mattsan

Member
I have successfully attached an AT875R pro shotgun mic onto my GH1 without any addional gizmos!

I found out that the mic port is DC 2.5v active and this is enough to power the mic!!! (which normally needs phantom power 48V to work)

see pics here 3 in total

http://www.vimeo.com/groups/gh1/view_file:5107

The sound quality is greatly improved over the internal mics and panasonic Gh1 mic.

just thought i'd share this info with ya
 
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Sweet. Have you noticed any problems with the auto gain? Also, any chance of getting some more info on your custom mount and the cable used? Thanks.
 
No problems with auto gain (well no more than the onboard mic) still a bit of hiss from the camera pre amps (but less than buit in mic) (when I had this mic on my Sony EX1 there was like ZERO hiss so I know the mic isn't making the hiss)

The custom mount is basically a normal mic holder with a thread convertor into a flash shoe holder.

The cable is a 2.5mm stereo 90degree jack to bare ends. I made the connections using the standard balanced to unbalanced connection notation, namely..

red and white (Left and right) to pin 2 on XLR all other pins and cable shield connected together ie XLR pins 1 & 2 connected to ground.

I am surprised I havn't seen anyone else do this - to me I appear to be the 1st to put a phantom powered mic onto the GH1 without any additional electronics.
 
I reported success with phantom powered mics some time back, but the particular mics are sold as being also compatible with lower voltages eg "plug in power". I'm surprised at your success with that shotgun!
 
I've just ordered this exact mic with a mount and XLR -> 3.5 adapter. Pretty stoked to use it... should be good judging from the audio tests I've listened to.

Pearstone PELMT100 LMT100 - Low to High Impedance Matching Transformer
1 $19.95 $19.95

Pearstone PEDUSM1 DUSM-1 Universal Shockmount for Camera Shoes and Boompoles
1 $49.95 $49.95

Audio-Technica AUAT875R AT875 Short Condenser Shotgun Microphone
1 $199.95 $199.95

Sub Total: $269.85
Shipping: $16.30
Sales Tax: $0.00
Total: $286.15

That's my exact order from BH if anyone was wondering what mount and converter I got. Hopefully I'll now have awesome GH1 audio for under $290, wooooo (I know about the AGC, have to get around that somehow, maybe the beachtek).

Now I just need to get a nice 3.5 to 2.5 adapter? Anyone like anything in particular? I'll probably order online.
 
Dang!!!! It's not working for me :( Did you use a 3.5 to 2.5 adapter OP?

I am using one from Radioshack, 2 black rings, matches the 3.5... but dang it's not working for me :(
 
I think my problem is somehow my adapter...

I see you didn't use an adapter there, any link to where I can get an XLR female to 2.5 male cable? Couldn't find one yet...

I currently have this cable: XLR female to 2.5 male http://www.bhphotovideo.com/c/product/589872-REG/Pearstone_8111240_LMT100_Low_to.html

Pearstone LMT100 - Low to High Impedance Matching Transformer

I guess it does the Balanced mic to Unbalanced recorder thing. I have no idea why this is not working with my 3.5 to 2.5 adapter on it...
 
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UPDATE: IT WORKS!!!!

I got a simple Hosa female XLR to male 3.5, put the radio shack 3.5 -> 2.5 adapter on it (2 black rings, matching the 3.5) and it worked!

Mattsan informed me that the Low to High Impedance Transformer was killing the electricity running to the mic, so it wasn't getting its phantom power. Now it works, sweet sweet sweet. Really nice little setup I have now, of course we'll see how bad the AGC plays out.
 
Cool stuff. Perfect for a run-n-gun quickie. I have the H4n but I can see the benefits for using a quick setup like this.
 
Really nice little setup I have now, of course we'll see how bad the AGC plays out.
Click to expand...
The AGC performance varies according to how well the output of the external equipment matches the GH1 input. Obviously if the level going into the GH1 is excessive then the AGC will be trying to clamp it all the time and it will sound a bit nasty (and possibly distorted). If it's too low, then the AGC won't cut in so much but noise will be a problem. To get an idea of whether the level is right, try testing with and without the external mic on a steady sound source and see if the levels generally match.

Looking at GH1 built-in mic waveforms it seems to me that the AGC is more of a compressor/limiter - it doesn't seem to turn quiter sounds up a great deal, it's chiefly intended to avoid overloads with a fast-acting detector (and return to normal level is fast too). I've heard worse.
 
The level is about right - no up n down breathing of the AGC under normal and slightly above normal loudness. The AT875R mic is more sensitive than the onboard ones and outputs a slighlty higher signal so the SNR is better and thus gives less hiss for the same sound compared to the onboard mics

I am very happy with this setup and would recommend to others looking for a similar solution.

i am sure 'yabyum' will report his experiences soon too.
 
Great thread. I was just looking at buying an AT 875, so having the option to mount it on the GH1 sometimes makes it even more useable, cheers
 
I have a cheap AT-55 (the $50 shotgun LOL)

Is it even worth upgrading to a R0de for GH1 direct input?
 
I bought the AT875r to go on my GH1

I bought the AT875r to go on my GH1

Hello,

I did a test recording and picked up sound, but don't know if I am getting the true dynamic range of the mic with this camera?

I also have a Zoom H4N and was thinking I would make a coupler at the bottom of the camera to the H4N and then use the phantom power from it to the Boom mic.

This way, I'd have recording on top of the camera, recording on the front internal mic of the H4N and then a 3rd source with the Phantom power to the AT875r.

What says you? :)

Thanks in advance...

John
 
I successfully use my Sennheiser radio mics on the GH1 with a simple mini jack adapter
sound quality is not great because of the preamps and compression.

I still think serious sound is only possible with an extra audio recorder. and for the quick an dirty the internal mic is good for ...dirty audio...
 
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