HC3 Microphone Modification.

The Sony HC3 would be the perfect entry level HDV camera if it wasn't for the Audio options or lack of them.  We bought this camera for doing amateur movies and like everyone else, wish it had a MIC input.  The built-in MIC with its full time AGC (automatic gain control) is a real work of crap.  The Video is truly awesome, but when you marry it with mediocre audio, the unit does not balance out.  I expected more.  Almost returned it and bought the HVR-A1U instead.  But First....

We bought the Bluetooth MIC accessory  and returned it a day later.  That MIC is an OMNI directional and is just as thin sounding as the built in.  Next we tried the Gun Zoom (ECM-HGZ1).  This one equally sucks. By the way, the Zoom mode is an audio mix of the Gun MIC and the camera's internal MIC.  Fully zoomed in the audio is from the Gun,  fully zoomed out the audio is from the built in MIC.

We were going to get the "High Quality" stereo MIC, but decided that is most likely would not meet my standards.  So I sacrificed the HGZ1 in an attempt to add a MIC input.

After tearing open the ECM-HGZ1 MIC this is what I found!  Remember, this is only for the HGZ1.

Pinouts from the AIS (Active Interface Shoe) to the HGZ1 circuit board.

AIS    HGZ1    Volts             Function

1        1             0                   Ground (camera chassis)

2        10           +1.22VDC   Audio Channel 1  (tied to pin 9)                 

3        9             +1.22VDC   Audio Channel 2 

4        8             0                   Audio Ground (isolated)

5        7             0                    ?

6        6             0                    ?

7        5             +2.8VDC      Control?  Is +1.25VDC in Gun Mode, 0.5VDC in Zoom Mode             

8        4             +7.4VDC      Is 0 VDC when MIC is switched to OFF mode. 

9        4                ""                    ""

10      3             +2.8VDC      Is +1.8VDC in Gun Mode, +1.74VDC in Zoom Mode           

11      NC

12      NC

13      2               0                    ?

14      NC

15      NC

16      1               0                    Ground (camera chassis)

I started to trace out the circuit, but ran out of time. Here's a pix of what I got so far.

Next I tried connecting a 3.5mm jack in place of the Gun MIC element.

I connected an external MIC (AKG C1000 Condenser) and the results were better, but not what I wanted.

I know the AKG MIC sounds better then what I was hearing so the only logical answer was amplifier on the HGZ1 was causing the problem

So I bypassed the on board amp and only left the on/off switch functioning.

Here are the pictures on how to do this.  You will have to remove a couple parts and solder your own MIC wires on the places indicated.

Removing these parts disconnects the onboard amp.

End result using an Audio Techica AT815B shotgun. 

I later added a bracket to position the MIC back about 3 inches to avoid seeing that thing at wide angles.

So how does it sound?  I'm very impressed with the improvement.  The frequency response is dramatically better.

Honestly, I no longer notice the AGC noise and hiss at all , but I do wish Sony would offer a way to turn it OFF.

The MIC you use will have to be a powered Condenser type, since no power is available from the 3.5mm connector.

Update:  Cody Curtin just returned from shooting in Downtown Portland.  We watched and listened a couple of times

and the quality of the audio now matches the video!  Hooray Beer!  I would recommend a decent shotgun MIC to get

the results we did.  The one in the picture is a Audio Technica AT815B usually around $275.