Audio control in the FX1
 

I have just had a look at the FX1 user manual, and I would like to confirm something.

How do you control your audio levels when you go in with an external mic?

Of course no one can expect to use such a camera as the FX1 and use the on-camera mics. You need to go in with an external signal to get quality audio, preferably using an external preamp or mixer to control eq and levels.

The FX1 manual has a disturbing note on page 36 that says "You can not adjust the volume of audio input from the audio/video jack".

Didn't the 2100 have an internal level adjustment to set an input audio level? Or is it the same as on this camera?


Carlos

If you are going in the external jack you will likely be at line level from a mixer of some sort.That's what I'll be doing anyway, and this mixer will control the level.

Ron Evans

Don't have an FX1, so if I get this wrong I apologize...

Are they referring to the RCA inputs? Sounds like you're looking at something different there. You should most definitely be able to adjust the volume on the mic jack, and I'm sure the FX1 has a volume dial (it controls both channels at the same time).

I think what the manual's referring to as the "audio/video jack" is the analog input/output that you'd use if you were using your camera as a tape deck, recording an analog signal from the RCA inputs. In that case you couldn't control the volume.

But you certainly can control it on the mic-in jack.

<<<-- Originally posted by Barry Green : Don't have an FX1, so if I get this wrong I apologize...

Are they referring to the RCA inputs? Sounds like you're looking at something different there. You should most definitely be able to adjust the volume on the mic jack, and I'm sure the FX1 has a volume dial (it controls both channels at the same time).

I think what the manual's referring to as the "audio/video jack" is the analog input/output that you'd use if you were using your camera as a tape deck, recording an analog signal from the RCA inputs. In that case you couldn't control the volume.

But you certainly can control it on the mic-in jack. -->>>

The input I was referring to is the audio/video jack up front, not the RCAs. What confused me on the FX1 manual, on page 36, is that Sony referred specifically to this input as not being internally adjustable.

Apparently it seems to be adjustable with the rotary wheel on the back, as I got to know recently from an FX1 owner.

Not only that, but that Sony also put a threadable 1/8" jack there, so you can firmly secured the plug when it's in, which has always been a weak point on mini-plugs.


Carlos

The 3.5mm microphone jack is switchable between mic and line level and then the level is further controlled by the rear rotary control. The RCA line in is not adjustable. However there appears to be a lot of white noise on the mic input at mic level and possibly even some oscillation/instability of the mic pre-amp. I am investigating this and will post again in the next day or so.

<<<-- Originally posted by Al Chapman : The 3.5mm microphone jack is switchable between mic and line level and then the level is further controlled by the rear rotary control. The RCA line in is not adjustable. However there appears to be a lot of white noise on the mic input at mic level and possibly even some oscillation/instability of the mic pre-amp. I am investigating this and will post again in the next day or so. -->>>

I have already seen your other post, and it's likely to be an AGC problem. At least you can feed a line level which, IMHO, should the way to better control it.

Just curious: what mic did you feed into the input? Had you used this same mic on any other semi-pro DV camera, having unbalanced inputs, like the VX2000/2100 or similar?


Carlos

AUDIO ISSUE RESOLVED: After a bit of fiddling I have found the definative reason for the audio problems I was having. The problems were being cause by a ground or earth loop. In the case of the Beechbox simply un screwing it from the bottom of the camera cured the problem. The other mics I had been trying were all connected via a XLR to 3.5mm adapter that I had attached under the microphone of the camera with a zip tie. The XLR was touching the camera body (which is aluminium) and creating a ground loop. This sugest that the ground for the mic input is not connected to the cameras chassis ground, or the grounding is not very good. Anyway don't ground the mic input to the cameras chassis and the audio input is clean.

<<<-- Originally posted by Al Chapman : AUDIO ISSUE RESOLVED: After a bit of fiddling I have found the definative reason for the audio problems I was having. The problems were being cause by a ground or earth loop. In the case of the Beechbox simply un screwing it from the bottom of the camera cured the problem. The other mics I had been trying were all connected via a XLR to 3.5mm adapter that I had attached under the microphone of the camera with a zip tie. The XLR was touching the camera body (which is aluminium) and creating a ground loop. This sugest that the ground for the mic input is not connected to the cameras chassis ground, or the grounding is not very good. Anyway don't ground the mic input to the cameras chassis and the audio input is clean. -->>>

That is very good news!

A very common practice that should be avoided, if you make your own cables, is to connect the ground to the XLR metal body. The metal case should always be floating, exactly to prevent ground loops. If you buy a ready-made XLR cable verify the body is floating, and if it is not open the connector and cut the link. On both ends.

Another advice which I expect every FX1 owner to follow is to build/buy a mini-plug to XLR adaptor (Y cable). Then plug it in, screw it in and forget about it. Fix it somewhere with velcro and always make your further connections to the XLR terminals.

One problem early Beachteks had was that the ground could not be floated, which I think was solved later on.



Carlos

I have just finished modifying my beechbox and the case is now isolated from the audio ground so I can screw it onto my camera without any problems.