using a microphone preamp with the dvx?

G

gossamer

Active member
hi all.

I'm new here but I've been lurking around for a while and you all appear to be a helpful, good-natured bunch.

I'm an audio recording engineer but I've recently gotten into DV work (both at client demand and personal interest). i'm getting a dvx100 for shooting shorts and also doing interviews and some corporate work.

Because I've worked very hard to earn a repuation as a good recording engineer, good, high-quality audio is of serious concern to me with my dvx.

my question: has anyone used an outboard micrphone preamplifier (mic pre) going into their dvx100? Is it even neccessary? Can you trim the on-board mic pres on the DVX to accomodate a line-level signal coming off an outboard pre without distorting to the A/D converters?

I know the camera has on-board mic pres. But at the price point these can't be what I've grown accustomed to as "studio quality" mic preamps.

in audio recording, we typically get superior results when we use outboard microphone preamps going into a A/D converter, digital workstation, or mixer (and even spend thousands of dollars on various boutique mic pres for different types of coloration of the sound). i've developed a sensitivity to audio for film and I want the dialogue to sound as good as possible. I've purchased a sennheiser lav and k6 kit, so i think i have a reasonable front-end. The mic pre question is the big mystery at this point (and I'll have TONS of questions about the camera soon.)


Any help on the preamp question is much appreciated. If anyone has anu questions regarding audio, music recording, VO, etc. for film please feel free to ask.

thanks in advance.
 
Re: using a microphone preamp with the dvx?

Welcome gossamer! That was the point with this camera to have true 48v phantom power. You are the first person to suggest a pre-amp. But I'm not a sound guy. What do you mean buy "pres"? 8)
 
Re: using a microphone preamp with the dvx?

hi, thanks.

re: "pres" sorry, that's a short for "preamp." mic pre is "microphone preamplifier."

re: 48v phantom. the 48v phantom power supplied by the camera powers the actual power the mic needs to perform. but this is different than pre-amplifing the signal. condensor mics (the shotguns and some lavs) need power to operate (or a battery). But all mics need to be pre-amplified - that is, brought from a low-impedance "mic level" signal to a line-level signal which is what gets converted to digital and printed on the DV tape.

In audio recording we often find that the mic pres on mixing boards, cameras, etc. are rarely studio quality (they impart noise from the FET amps, less-than-flattering coloration, etc.). I have a few brands of stand-alone mic preamps which I've found to really flatter the human voice for voice over. So I was hoping to make sure I could use these to preamp the signal going into the camera.

If I can trim the pres on the camera it's no problem. but if they're really "hot" then I run the risk of distorting to tape.
 
Re: using a microphone preamp with the dvx?

Hi Gossamer,

I asked this question on an audio forum, and what they said was the audio quality in the DVX is extremely good and doesn't really need a pre-amp. While the signal to noise ratio possibly could be improved if a really good pre-amp were used, it really isn't necessary.
 
Re: using a microphone preamp with the dvx?

Hi Gossamer,

The DVX100 can handle line level in as well as mic level at -50dB or -60dB. Line level, I believe is 0 dBu. So yes, feed her whatever you want.

I have recorded band and orchestra music with a pair of AT4033s in an ORTF configuration, and got excellent sound with the built in preamps. There's no doubt that a Great River preamp would make things sound pretty neat, or color it however you will.
 
Re: using a microphone preamp with the dvx?

Gossamer, as a sound guy how do you like AT mics like the new AT897 compared to the ME66 and the classic 4073a compared to the Sennheiser 415? 8)
 
Re: using a microphone preamp with the dvx?

[quote author=scottchapin link=board=Events;num=1076284883;start=0#4 date=02/09/04 at 18:22:28]I have recorded band and orchestra music with a pair of AT4033s in an ORTF configuration, and got excellent sound with the built in preamps. There's no doubt that a Great River preamp would make things sound pretty neat, or color it however you will.[/quote]

Hi Scott.

Thanks for the information. The DVX arrived today (great service from B&H) and I found just what you pointed out above. Line-level switch, which is exactly what i needed.

I LOVE the AT4033. Those are my VO mics of choice. They are also excellent on drum overheads, acoustic guitars, and can even handle close-micing a electric guitar cab if needed. That Great River is a sweet pre.

Elvis:

When it comes to condensors I am an AT devotee. AT has REALLY developed some great price:performance products in the last few years.

Regarding mic preamps: (you guys could get me talking about this all day)
In just some preliminary tests I've done today since delivery, I found that using an outboard preamp was an improvement over the on-board DVX pres. The DVXs weren't bad by any stretch, but outboards did help on a voice source. Most outboard pres can be expensive (ie. I spent over $2k USD on a pair of old Neve mic pres from an 80s console). However, the market is coming around and developing some really nice, mid-priced-but-pro-level pres. If you are looking at improving your audio side I recommend the FMR Audio RNP (it stands for "Really Nice Preamp") This is a stereo pair of very transparent and nice sounding preamps for around $500 MSRP

Link http://fmraudio.com/

The preamp is on about 8" 6" wide and 7" deep and 2" tall, so it's easily transportable. You'll need to get or solder up an XLR (DVXside) to 1/4" TRS (preamp side) adapter, but this is simple to make and even simpler to get at any decent audio store. This would make a really nice, roadworthy audio setup (and no, I don't work for AT, Sennheiser, FMR Audio OR any company that carries their stuff) and it's what I have assembled for audio in interviews, etc.)

Thanks again for all your help folks.
 
Re: using a microphone preamp with the dvx?

Hi Gossamer...

Being an audio engineer myself, I wondered the value of the onboard pres as well... but having used them for awhile, They're really not too bad (imho). Just for giggles I plugged a U87 up to it once, and it was really pretty sensitive without much (too much) coloration from the pres. Granted they're no Neve's or Avalons, but they work suprisingly well for a camcorder rig...
 
Re: using a microphone preamp with the dvx?

Gossamer, That FMR RNP looks really tight. I wonder how much cord there is between the unit and the wall wart. I would want to perhaps figure a way to tripod mount it, and couldn't have a wall wart dangling.

FMR stuff is really lauded, and I would like one.
 
Re: using a microphone preamp with the dvx?

Hi Scott:

The FMR power supply cable is about 6' long. You could use a longer mic cable to connect the preamp to the DVX, otherwise you'll be looking and a dangling wart.

Eeeeew! ;D
 
Re: using a microphone preamp with the dvx?

[quote author=gossamer link=board=Events;num=1076284883;start=0#9 date=02/11/04 at 17:19:04]Hi Scott:

The FMR power supply cable is about 6' long.  You could use a longer mic cable to connect the preamp to the DVX, otherwise you'll be looking and a dangling wart.

Eeeeew! ;D[/quote]

Right now I'm using a Mackie 1202 VLZ Pro. It's OK, but bulky. I was thinking of getting a Sound Designs 302, but don't know how it would measure up against a real studio preamp (with which I have no experience).
 
Re: using a microphone preamp with the dvx?

Question for you audio guys: I'm using an SM58 as a boom mic to record audio, is this a good or bad mic to use?

I like it because it's small, quick and easy to set up. I haven't heard sound recorded from other mics on this camera...in general though, is this getting me decent quality sound for dialogue?

And I apologize for sounding really stupid, I'm just not an audio guy, that's all!
Thanks.
 
Re: using a microphone preamp with the dvx?

In general, Shure makes great mic's. That particular one is a handheld, with not a very wide frequency response (but wide enough for speech).

While it is not the right tool for the job (as far as a boom mic goes), at least it is a good quality mic, so if you're getting satisfactory results with it, well... go ahead and use it!
 
Re: using a microphone preamp with the dvx?

Mike:

One thing to consider with your SM58 is this: The 58 was made to be primarily a live vocal mic. Therefore, it has pretty good off axis rejection (picks up sounds directly in front of it better than those off to the sides). Therefore, there is going to be less of the ambient sound picked up by the mic than the sound directly in front.

Also, holding it above the speaker is going to give the voice a more "nasal" quality. So, compensate for this by getting it as far in front of them as you can w/o getting in the frame. Where you aim the mic is what they'll sound like.
 
Re: using a microphone preamp with the dvx?

Scott:

The FMR preamp isn't going to mix like the VLZ, but the pres are a big improvement. I use a Mackie 1604 VLZ in the studio, but only for routing headphone/monitor mixes. The FMR is small, easy to use, and sounds really great.
 
Re: using a microphone preamp with the dvx?

[quote author=gossamer link=board=Events;num=1076284883;start=0#15 date=02/14/04 at 13:57:04]Scott:

The FMR preamp isn't going to mix like the VLZ, but the pres are a big improvement.  I use a Mackie 1604 VLZ in the studio, but only for routing headphone/monitor mixes.  The FMR is small, easy to use, and sounds really great.[/quote]

I found some comparison tracks, albeit MP3, at www.thelisteningsessions.com. Amazing difference.
 
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