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-   -   Can't work a DXA-6 or a boom pole (https://www.dvinfo.net/forum/all-things-audio/43506-cant-work-dxa-6-boom-pole.html)

Robert Martens April 24th, 2005 02:31 PM

Can't work a DXA-6 or a boom pole
 
Two problems for the price of one! Act now, while supplies last...

First things first, I'm encountering a difficulty with my Beachtek DXA-6 (my -4 got damaged, and I can never resist an opportunity to buy new stuff). Here's the deal: I have a Sennheiser ME66/K6 combo, without battery, attached to the left channel of the DXA-6 with a twenty-five foot Audio-Technica XLR cable. The Beachtek is then plugged in to the mini jack on my VX2000. Finally, I'm monitoring the audio with a pair of 7506 headphones, plugged in to the camera's headphone jack.

On the Beachtek adapter, I have the left channel 48V phantom power on, and the Mic/Line switch set to Mic. The right channel controls are off, except for the level dial, which is all the way up, as instructed by the manual. The Ground switch is set to G1, and the Mono/Stereo is on Mono. In camera, I have my Audio at 16 bits, and the Mic Level is manually controlled, with the recording level set to fifty percent. The mini jack switch is set to Line.

In this configuration, with a fresh 9V battery in the DXA-6, and all power switches on, I find I don't get any sound. Or at least it seems that way. When listening through the headphones, I can just barely hear audio on the left channel, but it's mostly hiss. The right channel is nothing BUT hiss. Horrendous hiss, at that. Even with the Mic Level all the way up, I get but the faintest wisps of sound. The audio meter shows me that there's a signal coming in, but I had to capture the video to my computer and crank my speakers up to hear it.

Now, you might say, "The VX2000 is a very noisy camera; you should know that by now." You're right, and I do. The thing is, I'm used to what kind of noise I typically get out of this thing, and it's nothing like this. As a matter of fact, when the microphone is powered by a AA battery, and connected directly to the camera with a simple adapter, and with the camera's mini jack switch set to "Mic", I get clean, clear, loud sound, and can safely keep the Mic Level below fifty percent. The hiss becomes negligible at this point (for someone like me, anyway).

After a search of these very forums, I discovered that perhaps the cable was defective--a rare occurrence, but still possible. Alas, I ran into the same problem with a much shorter (foot and a half) XLR cable.

I also tried setting the mini jack switch on the camera to "Mic" with the Beachtek attached, with no success. "Line" gives me a useless signal, but "Mic" doesn't give me anything but the onboard stereo mic.

Next up was to try using the ME66/K6 on AA battery power, while still connected through the DXA-6, but with phantom power off. Same scenario: lots of hiss, tiny signal.

I have tried every conceivable combination of switches on this thing. The Ground switch doesn't change anything, nor do the Mono/Stereo or Mic/Line switches. I was worried--and still am, to some degree--that the camera was damaged, and the audio circuits have been irreversibly altered, but as I said before, plugging the ME66 in directly works like a charm. This leads me to believe I'm doing something wrong, not the camera, though I can't figure out what for the life of me.


My second problem is with this Gitzo boom (an aluminum G-557): I can't get the mic, in an AT8415 shockmount, to stay put on the end. As I've read, it's entirely possible, and often necessary, for a boom operator to whip back and forth between two individuals during a conversation. Or even in cases of just one actor, it's expected that the operator will be able to spin the mic to keep up with any movement (isn't it?). I find, however, that I'm unable to spin the pole with ANY amount of speed without the shockmount coming loose, and spinning around. Once that happens, the microphone becomes impossible to aim. Is there some sort of trick to securing these things? I see the pole came with two little...thingamabobs on the end of it (a knobbie-lookin' thing that's sorta like an asterisk, and a cap that seemed to be more of a thread protector than anything else). The instruction sheet, aside from being in French, is what you might call an "exploded" view of the pole, and looks like more of a parts list for those who need to order replacement pieces. It has been no help.

Am I missing something obvious here?

Jay Massengill April 24th, 2005 06:57 PM

The camera's mini-jack should definitely be set to mic.
Try cleaning the BeachTek's mini-plug with a soft clean cloth. Also make sure it is plugged all the way into the camera jack.
Do you have anything else with a mini stereo mic jack that you could hook the BeachTek to and test that?
Have you tried the mic in the other channel of the BeachTek?
Also the "left" and "right" channels of the BeachTek are correct for looking at each end of the box. In other words, the left control on the front applies to the jack that's on the left when you turn the box around, not the jack that's immediately behind the left controls when still looking at it from the front. Know what I mean?
The Gitzo poles I have use a double-ended stud that's removeable. It's 3/8-inch on one end and 1/4-inch on the other. It also has a wide plastic disc with finger grips, that acts like the trim ring on a regular mic stand. The rubber piece you mentioned is just a thread protector. So you have to make sure the pole, trim ring, stud and shockmount are all tight together. Basically just torque them by hand until all snug and make sure there's no lubricant on the threads. You may also want to keep the mic as close to centered length-wise in the shockmount as you can. This equalizes the torque the mic can apply to the mount when rotating the boom pole.

Robert Martens April 24th, 2005 09:39 PM

Of all the stupid things...you'd think I'd have had the presence of mind to try the adapter with something else first. Sorry 'bout that. That seems to have settled it, though. Plugged the Beachtek into the mic in on my laptop, and the sound is wonderful! Guess the camera needs to be repaired. And yes, I made sure to use the jack and controls that were LABELED "left", not simply ON the left. Seems like it would have been very easy for them to just run the stuff straight through, I'm glad to see they went that extra mile. Very cool.

Regarding the pole, that plastic disc with the grips on it is the asterisk-thingie I mentioned. I have to say I've never had the opportunity to work with a mic stand, and have no idea what a "trim control" does. I also have the removable, double-ended stud, and there seems to be some sort of black/grey stuff on it that comes right off on my hands. Not sure if that's lubricant, or something left over from the manufacture of the pole. Doesn't make a difference now, however, as everything is secure (the threaded stud is on the end of the pole, the shockmount is attached to that, and the plastic disc tops it all off--is that right?). Gave it a quick re-tightening, and the shockmount is snug as a bug, even though the mic is off center (any closer than I have it now, and I'd be covering up some of the, uh, "sound holes" lining the barrel). You'd think I would have figured that out, but I guess I didn't, for whatever reason. Could've sworn I tried that already, maybe my short term memory isn't so great. What? Where am I? What am I doing?

I appreciate your help, thanks!

Robert Martens May 3rd, 2005 02:03 PM

Waitaminute. I hate to dredge up an old post, especially after its left the first page, but something just occurred to me: if I'm correct, and my camera's audio circuitry is damaged, then how come the microphone works when plugged in directly? The DXA-6 works when connected to other mini-jack devices, so I figured the camera was to blame, but it hears the mic just fine.

Isn't that strange, or is my lack of electrical training keeping me from seeing something obvious?

Jay Massengill May 4th, 2005 07:06 AM

Yes it is strange, but with mini-plugs almost anything can happen. There are slight differences in dimensions of all mini-plugs and the mini-jacks are very easily stressed and worn. The forces of the spring contacts are very small and the electrical energy from a mic is so slight that even a fingerprint can provide substantial blocking of the signal.
Your jack is probably worn a little but the mic is still making good contact while the BeachTek isn't. Make sure all the mini-plugs are cleaned with a soft uncontaminated cloth. Plug them in gently but fully, then gently rotate the plug slightly. This may get your BeachTek working with the camera again, but there's no guarantees with mini's.
Also, have you tried the G1/G2 grounding scheme switch on the BeachTek?

Robert Martens May 5th, 2005 11:14 PM

Problem solved! I tried what you suggested, but nothing helped. Cleaning the plug, inserting it carefully and twisting, nothing. So it came down to me taking the camera apart--partially this time--to have a look. Lo and behold, the ribbon going from the mini jack to the PCB in the camera's handle was cockeyed. Took it out, reinserted it, Beachtek works like a charm.

Let that be a lesson to those of you crazy and/or stupid enough to disassemble your three thousand dollar camera: make absolutely sure you fully seat all your cables when you're puttin' the thing back together.

And yes, I've heard plenty of lectures on the virtues of not doing this without the proper training, so cool your jets. I know how dangerous this is. ;)

Funny thing, now I have the audio in the right ear of the headphones (yes, I'm wearing them correctly). Double checked my mic connections, everything's on the left, but the sound is on the right. Odd, but what I hear sounds wonderful, so I can't complain.

Thanks again for all your help, Jay!

Mike Cook May 9th, 2005 06:03 AM

On the Gitzo. I made life MUCH easier on myself by putting two thin rubber washers on the pole. One on each side of the knurled knob. Makes tightening easier and holds everything in place better.

Make sure they are THIN washers, too think and they can cause slop/noise.

Robert Martens May 9th, 2005 12:21 PM

Ooh, sounds like a good idea. Thanks for the tip, Mike! I'll give it a shot.


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