AT897/DXA-8 Hiss at max. volume...
 

I recently bought a Beachtek DXA-8 to use with my Audio Technica AT897. The DXA-8 certainly boosts the signal level from the mic, but I've noticed that there is an audible hiss through the earphones when I set the Beachtek up near maximum amplification. Is this normal?

Initially, I detected some really noticeable noise coming from the Beacktek, but discovered that if I turn off the unused right channel and set the Beachtek to mono mode, that noise is eliminated.

The only remaining problem is the hiss. It seems that no combination of preamp gain and camcorder audio gain (in manual mode) can be found to totally eliminate this hiss. It is much noisier than the internal mics.

Anyone have any ideas about this? Could I have gotten a bad preamp?

Bob Reed

What cam are you using? If its a VX2k the headphone circuit is noisy no matter what but you wont hear the hiss on playback through monitors or phones hooked up to your NLE etc.I dont own the DXA-8 yet but am planning on getting it.Bryan Beasleigh did a small review here and liked the unit and did not report any hiss with several different mics and gain settings.

Matt -

I am using it with a Canon GL-2. Although I haven't tried actually recording the audio to tape yet, the hiss is much more noticeable through the headphones when using the preamp than it is with the built-in mic. That's what convinced me that DXA-8 is to blame.

I should also note that everytime I have used the DXA-8, I had it screwed to the bottom of the camera. I will try it tonight with it disconnected from the camera body (it may be picking up electromagnetic noise from the camera).

The key is to set up a realistic recording scenario, with realistic levels, normal micing distances, etc. Record that and capture it to your NLE. Set playback for normal monitoring levels through your editing speakers. Then decide whether you're getting enough gain without additional noise.

If you don't have a mic on channel 2 then there is no reason to switch it on, is there? A mono stting will give you audio on both channels, stereo will separate the right and left channels. Read the manual, it's very clear

As a general rule you should never run any electronic gear at max gain. Where do you have your camera gain set?

The is a grounding switch as well. If you read the manual it will tell you what to do.

To properly test the unit you should actually record audio to tape and play it back on monitors or good quality headphones. I tried this unit with a $1200 mic, a $400 and even a $100 dynamic mic with absolutely no hiss. I also never had to raise the gain past 70% (with a dynamic mic), with condenser mics the gain was around 40-50%

Do you have the camera set for manual or auto gain control?

I just found and read the manual. It's actually very easy and most of the setup is on page 57.

In menu turn audio level ON

Set audio to manual on the slide swictch by the audio level incicators.

Turn the L and R controls to set level (start at 40%)

Turn mic attenuation OFF

All of the above are important.

Bryan - I am not aware of any manual that's 57 pages long. The DXA-8 comes with a two-sided, one page usage guide. That's it.

I am currently set up with the mic attenuation turned off, the mic volume levels on the GL-2 set at about 40% and the mic levels on the DXA-8 set at near 100%. I set it to these levels in order to get -12db vol. levels. Perhaps I can just cut back a bit on the DXA-8 and settle for a bit lower levels.

Or bring the GL2 levels up. The GL2 doesn't suffer from a lousy preamp.I wouldn't run the DXA-8 higher than 75% leave the DXA-8 at 7 0r 7.5 and ride the gain on the camera. The GL2 doesn't have much gain by the sounds of it.



The manual I was referring to was the GL2..

Email me at bbeasleigh at rogers dott com

I'm going to buy an AT897, but I was going to buy the SignVideo XLR adapter instead of the Beachtek DXA-8, since it's alot cheaper.

This whole pre-amp thing is scaring me though. Do I NEED the DXA-8 to get audible levels from the AT897 into my GL2, or will the less expensive SignVideo adapter work?

someone please clarify this for me so I don't waste my money on the SignVideo.

The AT897 will drive the GL2's input without an external preamp.

Thanks for the tip.
Now that I know that the SignVideo adapter will work, is there any other good reason to get a more expensive Beachtek adapter instead? I don't really understand the differences between them, other than the fact that the DXA-8 has a pre-amp (that apparently I don't need)

Will I be happy with the SignVideo? Or will I regret not buying a better XLR adapter later?

thanks

There is always equipment that you don't have yet that will allow you to get better audio from more types of situations.

So if you're the type that tends to invest in his hobbies and wants his equipment to grow as his knowledge grows, you will outgrow the SignVideo adaptor. That's because you will want not only phantom power (which the SignVideo may already have, I forget), but also preamps and limiters.

Phantom power allows you more choices in mics, if you didn't already know, preamps help with signal to noise ratio when you have mics with weaker signals, and limiters allow you set your gain high to get good signal to noise ration while automatically preventing the clipping that would result from loud passages when the gain is set high.

The DXA-8 has all three features, but on the other hand you might want to go higher than the DXA-8 and get a true field mixer like the MixPre. I have the DXA-8 and I'm starting to think about the MixPre.

That doesn't necessarily mean you'll regret getting the SignVideo adaptor. It's a great improvement over not having an adaptor, and it will have resale value.

Personally, I would get the BeachTek DXA-6, which provides phantom power for better mics in your future. (For now the AT897 can run on internal battery if you don't get this BeachTek.)
This is still more expensive than the SignVideo unit, and is the best non-amplifying BeachTek. I think it represents better capability for the money, because you can use any mics with it.
If you plan on getting a new camera soon that may have phantom power built in, then the lower cost of a different unit might be a better choice.

The SignVideo unit is supposed to be ok too, but you have to use either dynamic or battery-powered mics with it.

You may also want to consider the Studio1Productions XLR-BP Professional unit. It hooks onto your belt instead of the bottom of the camera. Other than that it's very similar to the SignVideo.

http://www.studio1productions.com/xlr-bp_pro.htm

I really want the adapter to be mounted underneath the camera, so that rules out the studio1 adapter (thanks for the link though).

I think I may go with the DXA-6. I don't think I have a need for a pre-amp right now to justify the extra cost of the DXA-8, but the AT897 would be much more convenient if phantom-powered, and I do have access to several other mics that are phantom powered only (I think), and it would be good to be able to use those mics as well.

Also, this is a little off-topic, but: I am going to be buying the Sennheiser G2 wireless lav kit as well. So, with the GL2's hot shoe taken up by the mic, where would I mount the wireless receiver? I've seen those big two-hot shoe adapters, but they raise the two hot shoes pretty high above the camera, and I don't want anything that big. Is the Senn. G2's receiver small enough to mount under the handle of the GL2? or could I just stick it in my pocket with a cord long enough to run up to the camera?

Thanks

The receiver is pretty small. As long as you can keep the antenna vertical and as far away as possible from metal surfaces (this includes behind the antenna too), you should be ok. Pointed straight down works too if that's more convenient.
The 897 will perform best when it's away from the camera as well.
I know it seems like it adds huge bulk, but using a bracket to hold the camera, BeachTek, wireless and shotgun does add performance to the whole package.

Right now I don't have much of a choice other than to keep the shotgun mic on the camera. Its mainly going to be used at wedding receptions and other run-and-gun shooting where it has to be mounted on the camera. Besides, I'm a one-man-band at this point, and would not have a sound operator to hold it as a boom mic anyway.

Can you recommend any different brackets that would work well in mounting all this equipment onto the camera? (specific model #'s, please)

I need to keep it relatively cheap, as I'm already going over my budget.

I just found this adapter at B&H:
http://www.bhphotovideo.com/bnh/controller/home?O=cart&A=details&Q=&sku=146293&is=REG

It has two hot shoe connectors and isnt nearly as big some of the other adapters I've seen, and its not too expensive at $37.

Does the Sennheiser G2's receiver have a hot shoe port on it that would make it easy to mount onto this hot shoe adapter?

I think you have to buy this piece to get a shoe mount for the receiver.

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=328035&is=REG

<<<-- Originally posted by Fred Retread : The DXA-8 has all three features, but on the other hand you might want to go higher than the DXA-8 and get a true field mixer like the MixPre. I have the DXA-8 and I'm starting to think about the MixPre.

That doesn't necessarily mean you'll regret getting the SignVideo adaptor. It's a great improvement over not having an adaptor, and it will have resale value. -->>>

I'm on record as fully supporting Fred here as regards the MixPre. And please know that the MixPre is the entry level piece of gear for pros. There are many levels of proficiency and quality for gear. It's sort of like an aquarium; a lot of crap and scum on the bottom, but things get better as you get to the top.

The MixPre is one of those pieces of gear that you will grow into. I wanted more. I agonized and ended up with a Sound Devices 442 because I thought it would allow me to get work. I seldom use all four inputs, but there have been times when I have needed even more than four. (I ganged several mixers together)

The input limiters protect against unexpected shrieks and the multiple outputs and their limiters let me feed up to 3 cameras simultaneously without fear of overs. That comes in handy more and more for shoots with a locked down camera and a handheld.

Regards,

Ty Ford

Sorry, there's no way that I can afford the MixPre at this point. Too far over my budget.

Can someone explain limiters? I'm not exactly sure what it would do for me. I was looking at the DXA-6, but it does not have limiters. The DXA-8 does, but it's alot more expensive, and the DXA-6 is already pushing the limits of my budget.

What are the other advantages of the DXA-8 over the DXA-6?

G2 already comes with that accessory
 

<<<-- Originally posted by Jay Massengill : I think you have to buy this piece to get a shoe mount for the receiver.

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=328035&is=REG -->>>

The G2 units come with that shoe mount adapter.

<<<-- Originally posted by Chris Wright : Sorry, there's no way that I can afford the MixPre at this point. Too far over my budget.

Can someone explain limiters? I'm not exactly sure what it would do for me.


It'll let you record hotter signals without fear of overs.That gets you higher out of the system noise of your camera audio.

Regards,

TyFord