MA-100 XLR audio adapter questions

[Daniel Lynn]

One by one:

Yes, if I disconnect the right with the left still squeals.

Yes nothing was connected to the MA-100.

Correct, no squeal if I disconnect MA-100.

I don't have an AC adapter. I was powering it with a BP-945 "FOR CANON" (it's a generic brand). By DC adapter I meant the MA-100's adapter.

The squeal is steady. I don't know what frequency it is.

I was monitoring it with headphones, but I was also running my camera straight to my laptop and monitoring with quicktime pro.

[Don Palomaki]

Can you record other sources connected directly to the Audio1 inputs without squeal?

Can you try it with a different battery? Do you still get the squeal?

If so, and if the squeal records to tape with head phones disconnected, you may well have a defective MA-100. Quite possibly an internal short between the input and output. The MA-100 contains active circuits that provide about 6 db gain per channel, so it could go into oscillation on its own.

If you have some technician skills, you could test the MA-100 off the camcorder by connecting a +5 volt DC source to the tip of the power lead, and DC ground to the shield (NOT the tip) of one of the RCA plugs, and look for a signal at the RCA outputs.

[Daniel Lynn]

Update:

I've tried three different batteries, and yes other things input fine into the audio 1. Something I just noticed as I was messing around with it. If I let it power down completely, then power it back up, through monitoring and testing I discovered that at first the sound is fine, then the squeal occurs and builds upon itself until it's steady. This sound like an oscillation to me. I'm sending it back to B&H asap. Thanks for the help. I'll post a follow up when I receive a new MA-100.

[Don Palomaki]

Builds up over time - hmmmm, sounds like defective component in the MA100, possibly a bad capacitor or open circuit trace.

Sending it back sounds like the right thing to do.

[Daniel Lynn]

Don,

If issued an exchange for the MA-100 through B&H, but if that doesn't work and it's my cameras DC socket that's the problem, do you know of any other comparable substitutes for the MA-100. I was looking at the Beachtek DXA-4P or the Beachtek DXA-6 with phantom power. I'm skeptical, however as to how long the DXA-6 lasts with just a 9volt battery. Are there any other decent adapters? Hopefully the new MA-100 works just fine.

[Don Palomaki]

The common XLR adapters include models from Beachtek (http://www.beachtek.com), Sign Video (http://www.signvideo.com), and Studio 1 Productions (http://www.studio1productions.com). Each has advantages and disadvantages, and you can probably find users more than willing to share their opinions about them here and in other forums. One possible issue as you evaluate them is cable dress/management and control positions. Will they be convenient and/or in the way for what you are doing.

But I've not used them (can't speak to battery life) - I've been quite satisfied with the MA-100. And it provides the nice shoulder mount and accessory mounting platform to boot which none of the others have. But if doing 4-channel sound, a second adapter is nice to have.

[Daniel Lynn]

I received the replacement MA100, but the problem remained. Still a high-pitched hiss/squeal. It sounds like someone blew up a balloon and is squeezing the tip to slowly let the air out. I'm sending the replacement back to BH today.

I think I'm going to go with either a Beachtek DXA-6 or a DXA-4P. My big questions now is "how important to me would it be to buy an adapter with phantom power?" My microphone can be powered by a battery and as far as I know Beachtek has a decent preamp, so why would I need phantom power?

Is it just because in the future I may find myself with a battery that requires phantom power... and then I'll wish I spent the extra $70?

Is there another advantage to phantom power that I am over looking?

[Don Palomaki]

The primary advantage to phantom power is the wider selection of microphones. A second potential advantage is that some microphones have somewhat better output characteristics with phantom power than with battery power; e.g., a wider dynamic range, lower output impedance, or higher sound pressure levels for same level of distortion. But you will have to read the mic specs carefully to see if it applies to the mic you are considering.

Only you can answer whether or not it is a worthwhile benefit to you.

[Jim Ross]

It appears that the phantom power plug for my MA-100 is shot. Wiggle that puppy up at the flexible part right by the plug and the mic goes on and off. But I can't find a replacement plug anywhere. Tried Fry's, Radio Shack, etc, Any suggestions where to get a new plug? I tried a search in the threads and came up empty. Need this solved ASAP as I have a shoot this weekend! Argh!

Jim

[Greg Boston]

Just for clarification, that's not phantom power for the mic, it's dc power for the mic pre-amps in the MA-100.

Nevertheless, you might have to go with a more robust electronics store. We have a couple like that in Dallas with a lot more variety than the typical RS.

Look to see if Arrow Electronics or Allied Electronics might have what you need and a location that's local to you.

-gb-

[Jim Ross]

Thanks, Greg.
Any idea how I describe this thing over the phone? Like "It's a 1/8th inch whosieewhatsie blah blah blah?" Everyone keeps trying to sell me a mono or stereo mini audio plug to replace it and I hold it up side by side and you can clearly see the difference.

Jim

[Chris Soucy]

What is the difference? (I ask as I've never seen a MA100 or associated connectors). Any chance of a piccie?


CS

[Greg Boston]

Originally Posted by Jim Ross

Thanks, Greg.
Any idea how I describe this thing over the phone? Like "It's a 1/8th inch whosieewhatsie blah blah blah?" Everyone keeps trying to sell me a mono or stereo mini audio plug to replace it and I hold it up side by side and you can clearly see the difference.

Jim

Sorry Jim, I know it's smaller than the standard 1/8 (or 3mm) mini-phone jack. There is a slightly smaller size plug which IIRC is a 3/32 phone plug. I believe that's the size of the LANC connector (same size as many cell phone head sets). I haven't had my XL-1 for awhile so I can't check it out. I looked in my old Owner's manual and it doesn't say what size either.

-gb-

[Don Palomaki]

It is a 2.5 mm sub-mini mono phone plug. (aka 3/32" mono phone plug).

Some Radio Shack stores do carry them: part #274-290

[Jim Ross]

Originally Posted by Don Palomaki

It is a 2.5 mm sub-mini mono phone plug. (aka 3/32" mono phone plug).

Some Radio Shack stores do carry them: part #274-290

That's a little vague, Don. Could you be a tad more specific? LOL! Thanks! The only way you could have been more helpful is to have knocked on my door, part in hand!

Jim