Low self noise preamps for ambient recording?

[rkopald]

I'm trying to capture background ambient noise, birds, wind through the trees/bushes, city sounds, frogs, etc. I also record very quiet instruments. I was hoping that somebody would give me helpful feedback as to which preamps they've used that are well suited to these applications. My mics are very acceptable with self noise ratings of 12 an 20 dB, so I don't think they're the issue.
Thanks in advance for helpful replies!

[Audiop]

Hi!

I think 20dBA must be considered noisy for this kind of work, meaning that using such microphones I would expect audible noise from the mic.

Around 12dB and lower seems like a good start to me.


/Peter

[studer58]

Originally Posted by rkopald

I'm trying to capture background ambient noise, birds, wind through the trees/bushes, city sounds, frogs, etc. I also record very quiet instruments. I was hoping that somebody would give me helpful feedback as to which preamps they've used that are well suited to these applications. My mics are very acceptable with self noise ratings of 12 an 20 dB, so I don't think they're the issue.
Thanks in advance for helpful replies!

Yes as Audiop says, every part of the chain counts in your line of work.....fortunately we can do a little better than those figures for you (from an unlikely source, perhaps/even !)
RØDE Microphones - NT1-A

Apparently it's been verified by others too, so not just marketing-speak....hope it's of help to you ?
Ray

[rkopald]

Thanks folks! Atcually I did a field recording with the mics I listed, one with a noise floor of 20dB and the other with 12dB, and the 20dB one was unusable.
So that's real world evidence of your advice right there.
Any suggestions for preamps.????
Thanks again.

[NorseHorse]

Did you need to be portable? It's hard to offer suggestions when we don't really know what your needs are. Also, figuring out what your needs are will often reduce the need for questions. Can you use AC? Do you need battery power?

[rkopald]

Originally Posted by NorseHorse

Did you need to be portable? It's hard to offer suggestions when we don't really know what your needs are. Also, figuring out what your needs are will often reduce the need for questions. Can you use AC? Do you need battery power?

Oh right, sorry about that. for right now I won't be needing battery power. I've been fortunate to have AC access. When I get to the point of using a portable setup I think I'm just going to get a portable recorder, like a Zoom or a Tascam or something..

[rumleymusic]

AEA perhaps?

[rkopald]

Originally Posted by rumleymusic

AEA perhaps?

Those are nice!

[jaddie]

Look at preamp's Equivalent Input Noise spec. Good ones are at -127dB to -129dB or so, but due to thermal noise limitations it doesn't get more than a db or so better than that. You need the combination of a low noise preamp and a high output low self noise mic. For that you'll need a large diaphragm condenser with solid state electronics (tubes will be too noisy for you). The Rode NT-1A mentioned before is the most affordable lowest noise mic on the market. One caution, it has no low-cut filter, so it'll be difficult out doors, even with the required windscreen. Rode does make an LDC with a low cut and multi-pattern, the NT-2A with the same noise figure. It's a bit more expensive, and these are studio mics, not exactly rugged.

Jim

[MichaelPatrick]

DACS Micamp would probably work great in ambient applications because of low noise and magnificent clarity.

[Petrus]

Sennheiser MKH 30 and MKH 40 mics as a MS pair in dedicted Rycote blimp, Sound Devices or Nagra field recorder. Does not get any better than that for ambience/nature recording.

Those mics do not suffer from humidity and have the lowest noise figures of the kind. SD and Nagra recorders should be familiar already and their preamps are as good as any separate (at least battery operated) one.

SD and Nagra give about 19-20 bit real bit depth, pocket recorders you mentioned, while heavily advertized as 24/96 machines, are 15-16 bit machines, at most, in reality. Just check the specks, if any given.

[rkopald]

Originally Posted by Petrus

..DACS Micamp..
Sennheiser MKH 30 and MKH 40 mics as a MS pair in dedicted Rycote blimp, Sound Devices or Nagra field recorder. Does not get any better than that for ambience/nature recording.

Those mics do not suffer from humidity and have the lowest noise figures of the kind. SD and Nagra recorders should be familiar already and their preamps are as good as any separate (at least battery operated) one.

SD and Nagra give about 19-20 bit real bit depth, pocket recorders you mentioned, while heavily advertized as 24/96 machines, are 15-16 bit machines, at most, in reality. Just check the specks, if any given.

Thanks gents. I have a Sennheiser e609 I just picked up for recording guitar amps, and it hasn't blown me away with it's sound quality. then again, it was dirt cheap (like a hundred bucks), so that I get any decent results at all is a victory in my book. I'll look into the MKH mics. I've been wanting to acquire a figure 8 mic for MS recording anyway.
Haven't heard about the DACS stuff. I'll definitely check it out.
I'll also check out the Nagra field recorder.
15/16 bit seems like that'd be pushing it for really low volume stuff.. Thanks for the heads up on that.
Thanks everybody. Lots of great things for me to look into.

[MichaelPatrick]

Originally Posted by rkopald

Thanks gents. I have a Sennheiser e609 I just picked up for recording guitar amps, and it hasn't blown me away with it's sound quality. then again, it was dirt cheap (like a hundred bucks), so that I get any decent results at all is a victory in my book. I'll look into the MKH mics. I've been wanting to acquire a figure 8 mic for MS recording anyway.
Haven't heard about the DACS stuff. I'll definitely check it out.
I'll also check out the Nagra field recorder.
15/16 bit seems like that'd be pushing it for really low volume stuff.. Thanks for the heads up on that.
Thanks everybody. Lots of great things for me to look into.

fwiw, Sound Devices also make the 702, a fine 2ch recorder with the same electronics. The only difference is it doesn't do timecode and has no internal hard drive. Instead it can write simultaneously to a CF memory card and an external firewire drive.

Formats are WAV, mono or polyphonic; MP2/MP3 @ 64, 96, 128, 240, or 320 kb/s stereo; FLAC mono and poly.

Price is $1,875 US

P.S. I don't sell stuff. I'm just a Sound Devices fan.

[rkopald]

I was looking at that 702 recorder. Nice unit.

[adamboon]

Hi,

I'm beginning to feel like a broken record around here, but, Have a look at the Triton Audio D20 FET. 75dB of clean gain and holds it's own against pres 5x the price. also small and mobile.

Adam

[rkopald]

Originally Posted by adamboon

Hi,

I'm beginning to feel like a broken record around here, but, Have a look at the Triton Audio D20 FET. 75dB of clean gain and holds it's own against pres 5x the price. also small and mobile.

Adam

Those look really, really nice. I've been really leaning towards a DAV BG1, but this unit seems really solid. Now this and that paintpot preamp are grabbing my interest too.

[MichaelPatrick]

A quiet, fast and neutral preamp is a Gordon 5. Not cheap but, of all those I've heard, it is the best for low-noise highly accurate recordings.

I haven't heard Upstate Audio's Sonic Lens. It costs even more and is also a great option where money is no issue.

[Audiop]

Originally Posted by jaddie

Look at preamp's Equivalent Input Noise spec. Good ones are at -127dB to -129dB or so, but due to thermal noise limitations it doesn't get more than a db or so better than that.

EIN is stated as a "real" as opposed to "relative" value.. meaning something like dBu or dBV instead of dB.


/Peter

[didier.brest]

The preamp self-noise is not critical when the mic is a condenser in most cases. For instance, if the mic self-noise is 15 dBA, which is equivalent about to 28 dB SPL unweighted, and its sensitivity is 10 mV/Pa, then the mic noise level at the preamp input is 28 - 94 - 40 = - 106 dBV = - 104 dBu, which is much above the EIN from most preamps.

1 Pa = 94 dB SPL
10 mV/Pa = - 40 dB re. 1 V/Pa

[warhead]

Originally Posted by adamboon

Hi,

I'm beginning to feel like a broken record around here, but, Have a look at the Triton Audio D20 FET. 75dB of clean gain and holds it's own against pres 5x the price. also small and mobile.

Adam

I have to say, I've been using the tube / FET combo version (lower gain, more character) and I am now hoping to get the FET only version in (higher gain, less character it would seem) as this unit is really quite nice. The small size is also a plus for portable work.

On the microphone front, if you picked up a CAD e100s you would be amazed at how low noise / high detail that mic is. Really stellar stuff, and not priced bad either.

Another option to consider is grabbing the PHANTOM FETHEAD (another Triton product) which brings about +18dB of clean boost for condenser mics using your preamp's onboard phantom power. A cheap and clean solution for low $$$.

War

[rkopald]

Originally Posted by warhead

Another option to consider is grabbing the PHANTOM FETHEAD (another Triton product) which brings about +18dB of clean boost for condenser mics using your preamp's onboard phantom power. A cheap and clean solution for low $$$.

War

From what I can ascertain on the Triton website, this is super clean.
So the Triton pres work out to about $560 (US) per channel.
The BG1 works out to $600 for the unit, so twice as inexpensive...
Any thoughts? I have no problem shelling out 600 for one preamp, I was just curious if there is anybody around here that's used both??
And to the poster that pointed the RODE NT1A, that mic does indeed have quiet specs! I have an NTK, and it's a very quiet mic.. (I'm about to swap out the stock chinese tube for a JJ, made in the Slovak republic to hear what kind of difference I get, but that's an entirely different issue)
How does Rode keep their mic prices so low?

[A3rd.Zero]

What Petrus said.

I second the SD702. I have not heard quieter preamps in a portable recorder. I will also say that after using all manner of portable recorders, Edirol, Zoom, Sony, Tascam, etc, etc I have not found one that is more full featured or easy to navigate and set up. I have not used the Nagra recorders, the Sansonax recorders, or the Zaxcom recorders however.

Few features of the SD recorders that I love and can't usually find in other recorders:
Low/Normal gain range: Instant 10db pad on inputs
Ch1+2 stereo linking: Instant linking for stereo of ch 1+2 making the 1 fader a level fader and the 2 fader a balance fader
Ch1+2 MS stereo linking: MS decoding on ch1+2 built in
Ch1+2 MS headphone monitoring: Monitor MS decoding of 1+2 but only recorde them non MS so you can encode later at what you want.
Filename editing: you can format the recorder to record each file in any naming scheme you want. Most recorders surprisingly don't do this.
Clipping: Ive found that it takes a whole lot to clip preamps in a way that produces unappealing distortion. In fact I rarely use the limiters anymore letting the SD clip slightly so that the limiter doesn't effect the bottom end. These recordings turn out stunningly, almost like running a limiter with no adverse effects, you just loose the transient spikes to a clip (which I can't hear almost always).
Super Preamps: I've recorded everything from a kleenex falling on a patch of sod on a quiet foley stage to the tailpipe exhaust of an F1 car. These preamps will do anything, and do it well.

I also don't sell or rep SD products, I've just found for what I do, for the whole range of material I work with the SD is the best thing out there. It's smaller than the others (except for sansonax) and it can do anything. I actually use all of it's features all the time, which you might not do, but I also thought that I wouldn't need all of them and have bought three different non SD recorders and been dissapointed with all of them in comparison to the SD.

I use a RSM 191 (MS shotgun single point mic) with it, which is super quiet and very nice but not cheap.

I have also used an NT1-A with it which is good but not as good as the 191 due to the fact that it's gain is significantly lower. So while it may have lower self noise you have to gain up the recording to match it and then you have noise again.

Doug Oade recommended this to me and while I haven't tried it, the specs look good.

AKG 480B
Equivalent noise level 13db
Sensitivity 40mv/pa
Signal/noise ratio 81db

[rumleymusic]

How does Rode keep their mic prices so low?

Thank China

[rkopald]

Originally Posted by rumleymusic

Thank China

Yeah, except I'm pretty sure Rode does all their manufacturing in Australia now...There must be Chinese parts in there, but I don't know...

[panatrope]

Originally Posted by rumleymusic

Thank China

Maybe for setting low market prices but Rode are actually made in Sydney, Australia!

Back OT, by and large, as far as noise is concerned, preamp noise only becomes an issue using dynamic mics. For condensors, the amplifier in the mic tends to be the dominant noise source. LDCs will usually have the lowest noise due to the bigger acoustic aperture, SDC will be noisier (best of breed is around 11dBA self noise).

As an example, on the 'condensor' setting (10mV/Pa) for the preamps in the Nagra V, I measure about -123dBVA Ein at maximum gain, when terminated with a 150 ohm resistor. For my standard mic, which has a rated sensitivity of 12mV/Pa (-39 dBV) and a self noise of 14dBA, this gives its self noise output voltage of -119dBVA. The noise from the mic is 4 dB higher than the preamp, and combined they represent an effective noise floor of about 16dBA.

But if I set the gain to normal 'string quartet' levels (10mV=-40dBV= -15dBfs) which requires a gain about 20dB less than the maximum, then I find that the preamp Ein has risen to about -115dBVA. This means that the preamp noise is now 4 db higher than the self noise of the mic, and the combined effective noise floor of the combination is now about 20dBA.

In summary, for this combination, if you are recording very quiet sounds then it is the mic that sets the noise floor; if you are recording in a concert, then the preamp noise dominates. For me in either case noise has never been a problem, in the latter case, the NR of the venue is usually far higher than this. (Our new Recital Hall comes close, however.)

Mics like newer LDCs with single-digit self-noise ratings, will make the preamps more critical. High output mics (like some DPAs or Sennheiser MKHs) make the preamps less critical. Dynamic mics, which have 15-20dB lower output will test anything. Choose your mic first, do the calculations and then get a preamp to match.

As an aside, the preamps in my venerable 1202 VLZ read about -128dBVA.

[panatrope]

Originally Posted by A3rd.Zero

AKG 480B
Equivalent noise level 13db
Sensitivity 40mv/pa
Signal/noise ratio 81db

Actually if you choose the 'standard' setting of 20mV/Pa, the self noise level is 11dBA and sig/noise is 83dB. But then, what's 2dB between friends ....

[Rocket Ronnie]

Originally Posted by Petrus

Sennheiser MKH 30 and MKH 40 mics as a MS pair in dedicted Rycote blimp, Sound Devices or Nagra field recorder. Does not get any better than that for ambience/nature recording.

Those mics do not suffer from humidity and have the lowest noise figures of the kind. SD and Nagra recorders should be familiar already and their preamps are as good as any separate (at least battery operated) one.

SD and Nagra give about 19-20 bit real bit depth, pocket recorders you mentioned, while heavily advertized as 24/96 machines, are 15-16 bit machines, at most, in reality. Just check the specks, if any given.

This

[rumleymusic]

Yeah, except I'm pretty sure Rode does all their manufacturing in Australia now...There must be Chinese parts in there, but I don't know...

Yeah. Rode assembles and QC all their mics in australia, but the parts are made in China. In all fairness, most companies have at least some Chinese made parts.

[panatrope]

Originally Posted by rumleymusic

Yeah. Rode assembles and QC all their mics in australia, but the parts are made in China. In all fairness, most companies have at least some Chinese made parts.

Depends what you mean by parts? Components? Like resistors and capacitors? Who else makes them these days? AFAIK, capsules are made, boards assembled and and tested, cases machined in Oz. Maybe some of the lower lines or accessories are OEM'd from China.

Even so, if there is some sub-assembly in China, final assembly and test in Oz (not to mention design) is where it really counts. Some of the lower-level Nagra products are made in China (to Nagra specs), shipped to CH in semi-knocked down (SKD) form, QCd assembled and tested. Still goes out under the Nagra quality name.

Now, as we were saying about preamp noise ... ?

[rkopald]

Originally Posted by panatrope

...Now, as we were saying about preamp noise ... ?

Preamp noise bad.