Nagra LB or Sound Designs 722 or what?

[DrFrankencopter]

I need a recorder to capture the sound of aircraft interior noise. I'm using a Josephson 617 Set mic to capture the audio, and SPLs are quite high. Here's my requirements:

• Battery powered (must recharge while connected to AC)
• Records to solid state media
• 44.1 kHz wav
• High input headroom on mic ins
• +48V phantom
• Simple interface
• better than 3 hour battery life
• Good converters/preamp (at low gain)

I've tried using a Korg MR-1000 in this app, and it can't handle the SPL's, and the vibrations are murder on the hard disk. So far the best results I've had are with an Apogee mini-me connected via SPDIF to a M-Audio Micro track, but this arrangement is clunky (sometimes it doesn't sync to the SPDIF right, and it's too many different boxes to worry about).

I was thinking about either the Nagra LB, or the Sound Designs 722. Does anyone know how well these devices do with high signals on the mic ins? Or, maybe there's something else I should consider. Price should be <$4K.

Thanks

Kris

[David Spearritt]

Hi Kris,

I see from the specs of the 617 that the sensitivity is 66mV/Pa. So if the aircraft interior is 125dB linear say, then you are trying to feed a mic pre with 2.3V. No recorder preamp is going to cope with that. Its a line level signal.

You need a pad or a mic with less sensitivity, or try plugging it directly into the line level input on the recorder (with a separate 48V supply of course, perhaps battery supply).

[Gaston69]

I recorded last Thursday night a rock band with the Nagra LB and DPA4060 and thought that the signal was to hot as I couldn't lower the mic gain as it was at its lowest point. Signal was red all the time and thought the recording is f....d however when I came home everything sounded perfect!!!!

Try the Nagra, I do own also the Korg MR-1000 but I know exactly what you mean.

The Nagra rocks

There are many threads about Nagra LB which I posted including sound samples.

[Roland]

Originally Posted by Gaston69

I recorded last Thursday night a rock band with the Nagra LB and DPA4060 and thought that the signal was to hot as I couldn't lower the mic gain as it was at its lowest point. Signal was red all the time and thought the recording is f....d however when I came home everything sounded perfect!!!!

Try the Nagra, I do own also the Korg MR-1000 but I know exactly what you mean.

The Nagra rocks

There are many threads about Nagra LB which I posted including sound samples.

Isn't their a pad on the Nagra? I am just a little surprised that the gain range is that limited, I've recorded 4006's as drum OH's and not had any problem with too much level.

Regards


Roland

[DrFrankencopter]

Probably my best bet is to start by getting an in-line pad for the Josephson 617. I wonder if I can use the B&K pads there (the capsule is compatible with the B&K measurement mics, so I figure the pads should work too). I'm not keen on padding the output since I'd need a separate +48V supply.

Does the Nagra LB have input transformers like the Nagra VI? That could come in handy since I often connect one channel to the aircraft intercom, and having transforms could let me float that input (aicraft ground is NASTY).

Thanks for your help

Kris

[Baithak]

Originally Posted by DrFrankencopter

Probably my best bet is to start by getting an in-line pad for the Josephson 617. I wonder if I can use the B&K pads there (the capsule is compatible with the B&K measurement mics, so I figure the pads should work too). I'm not keen on padding the output since I'd need a separate +48V supply.

Does the Nagra LB have input transformers like the Nagra VI? That could come in handy since I often connect one channel to the aircraft intercom, and having transforms could let me float that input (aicraft ground is NASTY).

Thanks for your help

Kris

Dear Kris : Since you had difficulty with hard drives and vibrations perhaps a flash based solution would work? How about the 702 from SoundDevices?

Also, on my 744 I know I can leave the phantom power on even in line-in mode and once or twice I remember that I could easily get a hot signal from a Schoeps mic at the line level more easily than at the mic level. Perhaps the 702 would do the same? SD folks are always helpful with special requirements and I would suggest a call to ensure this is true.

Good luck,
Baithak

[Don S]

Originally Posted by Baithak

Dear Kris : Since you had difficulty with hard drives and vibrations perhaps a flash based solution would work? How about the 702 from SoundDevices?

Also, on my 744 I know I can leave the phantom power on even in line-in mode and once or twice I remember that I could easily get a hot signal from a Schoeps mic at the line level more easily than at the mic level. Perhaps the 702 would do the same? SD folks are always helpful with special requirements and I would suggest a call to ensure this is true.

Good luck,
Baithak

Yes, the newest update allows the phantom on for line level on the 702. FWIW, I believe you can set any of the SD recorders to record to CF only, bypassing the HD.
And the support from Sound Devices is amazing. Just one of the reasons I bought a 702.

[bove]

Originally Posted by Don S

Yes, the newest update allows the phantom on for line level on the 702. FWIW, I believe you can set any of the SD recorders to record to CF only, bypassing the HD.
And the support from Sound Devices is amazing. Just one of the reasons I bought a 702.

Sound Devices ships solid state hard drives on the 788 as an option, but you could install your own in any model if you wanted to. This way you'd still have the CF slot as backup, and remove vibration as an issue.

[MichaelPatrick]

I use c617s with a 744T and it works great.

The 702 costs less and uses CF, but it can write simultaneously to an external firewire drive if you need HD recording.

Powering is flexible. You can buy larger batteries since it uses standard Sony L- and M-Mount camcorder batteries. I bought a battery that has about twice the capacity of the stock battery. You can also connect the AC adapter or a 10v-18v external DC power source (like a sealed lead-acid battery) and that charges the camcorder battery just like AC does. Switching between the LiOn battery and external power is transparent. I've never lost a recording due to power. The thing is just bulletproof and reliable as a brick.

The input level controls are also flexible. Here's a quote from the 702 manual:

The microphone inputs operate in four gain ranges, NORMAL, NORMAL FADES TO OFF, LOW, and LOW FADES TO OFF. The NORMAL range controls input gain from 24.3 dB to 67.4 dB of gain. The LOW range controls input gain from 9.3 dB to 52.4 dB. The LOW ranges are useful for high SPL recording environments. The fade to off options allow for fader-like control of your gain. NORMAL FADES TO OFF provides a gain range of off or 0 to 67.4 dB and LOW FADES TO OFF provides a gain range of off or 0 to 52.4 dB.

[Don S]

Originally Posted by MichaelPatrick

I use c617s with a 744T and it works great.

The 702 costs less and uses CF, but it can write simultaneously to an external firewire drive if you need HD recording.

Powering is flexible. You can buy larger batteries since it uses standard Sony L- and M-Mount camcorder batteries. I bought a battery that has about twice the capacity of the stock battery. You can also connect the AC adapter or a 10v-18v external DC power source (like a sealed lead-acid battery) and that charges the camcorder battery just like AC does. Switching between the LiOn battery and external power is transparent. I've never lost a recording due to power. The thing is just bulletproof and reliable as a brick.
.[/I]

The 702 has one caviat. It cannot power a drive while on battery. If you're using an external drive, you have either plug in the drive or plug in the 702. I was a little bummed, but I use a Microtrack II as a backup.

[MichaelPatrick]

Originally Posted by Don S

The 702 has one caviat. It cannot power a drive while on battery. If you're using an external drive, you have either plug in the drive or plug in the 702. I was a little bummed, but I use a Microtrack II as a backup.

Good clarification. I wouldn't run an external drive on the camcorder battery anyway though others might want to.

Since the Microtrack II has a built-in battery that makes the entire system portable. I have one of these but with a 744T I don't need the extra backup. Do you write to your Microtrack II via SPDIF?