Become a Site Supporter and Never see Ads again!

Author Topic: Naiant Littlebox questions???  (Read 7715 times)

0 Members and 1 Guest are viewing this topic.

Offline F.O.Bean

  • Team Schoeps Tapir that
  • Trade Count: (126)
  • Needs to get out more...
  • *****
  • Posts: 40716
  • Gender: Male
  • Taperus Maximus
    • MediaFire Recordings
Naiant Littlebox questions???
« on: January 17, 2011, 06:05:19 PM »
Ummm, I am a newbie when it comes to transformers. With the lilbox, it has the option to come w/ input and/or output transformers. I am def getting input tformers, because they clean the signal and add gain, correct ??? What do the output tformers do ???

And what does the 'accessory amplifier stage' do or mean ??? And what does Jpon mean by having a custom panel design ??? Just the way things are configured on the front panel ???

TIA,
Bean
Recording Gear:
Schoeps MK 4V & MK 41V ->
Schoeps 250/0 KCY's ->
Naiant +60v/Low Noise PFA's ->
DarkTrain Right Angle Stubby XLR's ->
Sound Devices MixPre-6 & MixPre-3 ->
SanDisk 128gb Extreme Pro & 64gb Ultra Plus SDXC-I

Portable Playback Gear:
Campfire Audio Dorado IEM's >
Linum G2 SuperBax & Bax {3.5mm} | 
FiiO LC 2.5c {2.5mm} >
Shanling Audio M5s | Sony NW-A35 DAP's

DAW:
Dell Inspiron 15 5570-5521 Laptop

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline rjp

  • Trade Count: (0)
  • Taperssection Member
  • ***
  • Posts: 432
  • Gender: Male
  • You are likely to be eaten by a grue.
Re: Naiant Littlebox questions???
« Reply #1 on: January 18, 2011, 12:44:56 AM »
Output transformers do a couple of things: they electrically isolate the preamp output from the next recording stage, and, when driven at a high enough level, they saturate magnetically and distort the signal (add "color" to the sound) in a way that some people find pleasing.

While input transformers could theoretically saturate, in practice they're driven at much lower levels in a microphone application, and are thus unlikely to add significant distortion.

The accessory amplifier stage could be set up as a headphone amp for monitoring, or as a gain stage for the input. Either usage means extra current drain, though, while input transformers don't require any extra current.

Custom panels are needed when you start adding extra toggle switches (such as transformer bypass) or unusual jack combinations (such as mini-XLR inputs on the front panel). IMO, if you're using input transformers, a bypass switch is nice to have, in case you happen to be at a very loud show and/or are running hot mics.

Note also that the input transformer has no effect on the unbalanced PIP input; it is only a factor on the balanced XLR inputs.
Mics: AKG Perception 170, Naiant X-X, Sound Professionals SP-TFB-2
Preamps: Naiant Littlebox
Recorders: Olympus LS-10
Interfaces: Focusrite Saffire Pro 14, Focusrite Scarlett 2i2

Offline jbell

  • TDS
  • Trade Count: (143)
  • Needs to get out more...
  • *****
  • Posts: 4167
  • Gender: Male
  • Spreadicated
Re: Naiant Littlebox questions???
« Reply #2 on: January 18, 2011, 06:44:28 AM »
 

Output transformers do a couple of things: they electrically isolate the preamp output from the next recording stage, and, when driven at a high enough level, they saturate magnetically and distort the signal (add "color" to the sound) in a way that some people find pleasing.

While input transformers could theoretically saturate, in practice they're driven at much lower levels in a microphone application, and are thus unlikely to add significant distortion.

The accessory amplifier stage could be set up as a headphone amp for monitoring, or as a gain stage for the input. Either usage means extra current drain, though, while input transformers don't require any extra current.

Custom panels are needed when you start adding extra toggle switches (such as transformer bypass) or unusual jack combinations (such as mini-XLR inputs on the front panel). IMO, if you're using input transformers, a bypass switch is nice to have, in case you happen to be at a very loud show and/or are running hot mics.

Note also that the input transformer has no effect on the unbalanced PIP input; it is only a factor on the balanced XLR inputs.
« Last Edit: January 18, 2011, 02:31:37 PM by jmbell »
Microtech Gefell M20's> Nbob KCY> Naiant PFA(60v) > Sound Devices Mixpre-6 @24/48

-22        -12         -6        TDS     
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][}   
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][} 
__________________________
|Record|  Runtime: 4:19.99  {|||] 75%

Offline page

  • Trade Count: (25)
  • Needs to get out more...
  • *****
  • Posts: 8392
  • Gender: Male
  • #TeamRetired
Re: Naiant Littlebox questions???
« Reply #3 on: January 18, 2011, 09:59:57 AM »
With the input transformers you have a 0-32 gain range so I don't really see the point in having a switch to turn them off.  I never had any problems with overloading even at loud shows. 

Am I remembering correctly that the input transformers that Jon uses add 10db of "free" gain? If I'm thinking of the right conversation, then if you have mics that are under 20mv/pa, I agree. Over that, I'd want a switch depending on what recorder I'm using (and it's max input signal allowance).
"This is a common practice we have on the bus; debating facts that we could easily find through printed material. It's like, how far is it today? I think it's four hours, and someone else comes in at 11 hours, and well, then we'll... just... talk about it..." - Jeb Puryear

"Nostalgia ain't what it used to be." - Jim Williams

Offline jbell

  • TDS
  • Trade Count: (143)
  • Needs to get out more...
  • *****
  • Posts: 4167
  • Gender: Male
  • Spreadicated
Re: Naiant Littlebox questions???
« Reply #4 on: January 18, 2011, 10:11:36 AM »
They add 12db, but I was under the impression that the gain still started a zero.  Maybe I'm in the wrong.  I never even came close to having a problem with to much gain overloading the pre. 

With the input transformers you have a 0-32 gain range so I don't really see the point in having a switch to turn them off.  I never had any problems with overloading even at loud shows. 

Am I remembering correctly that the input transformers that Jon uses add 10db of "free" gain? If I'm thinking of the right conversation, then if you have mics that are under 20mv/pa, I agree. Over that, I'd want a switch depending on what recorder I'm using (and it's max input signal allowance).
« Last Edit: January 18, 2011, 10:15:07 AM by jmbell »
Microtech Gefell M20's> Nbob KCY> Naiant PFA(60v) > Sound Devices Mixpre-6 @24/48

-22        -12         -6        TDS     
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][}   
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][} 
__________________________
|Record|  Runtime: 4:19.99  {|||] 75%

Offline Todd R

  • Over/Under on next gear purchase: 2 months
  • Trade Count: (29)
  • Needs to get out more...
  • *****
  • Posts: 4889
  • Gender: Male
Re: Naiant Littlebox questions???
« Reply #5 on: January 18, 2011, 11:38:39 AM »
You might want to check with Jon on all of this.  On the input transformers, I think they add 12db of gain, and thus change the overall gain range from 0-32 to 12-44 (no way of not having the gain of the transformers, though he might change the gain of the following op amp gain stage to "correct" for the gain boost of the tranfo's, but I doubt it).

On the input and output transfomers, Jon has some posts here (be sure to also look down a few posts for further discussion):
http://taperssection.com/index.php?topic=122871.msg1656947#msg1656947

Overall, I think you're better off with output transformers for concert recording.  The input tranfos will lead to some level of bass rolloff.  At the same time, the presumably preferable coloration that transformers provide will be limited, as that results from transformer saturation, and saturation will be much lower with input tranfos since a mic signal is much lower than the line level signal coming after the preamp gain stage.  So if you're looking for additional gain and lower noise performance (neither of which really apply for concert PA recording, more like nature recording), you'd want input transformers.  If you want the euphonic transformer sound/coloration, you'd want output transformers.

I'd recommend output transformers that are switchable, so you can choose to use them or not (which is what I have on my littlebox).
Mics: Microtech Gefell m20/m21 (nbob/pfa actives), Line Audio CM3, Church CA-11 cards
Preamp:  none <sniff>
Recorders:  Sound Devices MixPre-6, Sony PCM-M10, Zoom H4nPro

Offline Todd R

  • Over/Under on next gear purchase: 2 months
  • Trade Count: (29)
  • Needs to get out more...
  • *****
  • Posts: 4889
  • Gender: Male
Re: Naiant Littlebox questions???
« Reply #6 on: January 18, 2011, 11:44:07 AM »
One more thought:

Input transformers do not "clean" the signal. The input signal is what it is.  They do provide cleaner gain (gain with less noise) than comparable gain from op amps or instrumentation amps.  But for concert PA recording, (1) you do not need that additional gain, and (2) noise performance really isn't an issue as the concert environment itself will have so much noise it will totally swamp any additional noise from the op amp gain stage inside your preamp.
Mics: Microtech Gefell m20/m21 (nbob/pfa actives), Line Audio CM3, Church CA-11 cards
Preamp:  none <sniff>
Recorders:  Sound Devices MixPre-6, Sony PCM-M10, Zoom H4nPro

Offline jbell

  • TDS
  • Trade Count: (143)
  • Needs to get out more...
  • *****
  • Posts: 4167
  • Gender: Male
  • Spreadicated
Re: Naiant Littlebox questions???
« Reply #7 on: January 18, 2011, 11:46:28 AM »



You might want to check with Jon on all of this.  On the input transformers, I think they add 12db of gain, and thus change the overall gain range from 0-32 to 12-44 (no way of not having the gain of the transformers, though he might change the gain of the following op amp gain stage to "correct" for the gain boost of the tranfo's, but I doubt it).

On the input and output transfomers, Jon has some posts here (be sure to also look down a few posts for further discussion):
http://taperssection.com/index.php?topic=122871.msg1656947#msg1656947

Overall, I think you're better off with output transformers for concert recording.  The input tranfos will lead to some level of bass rolloff.  At the same time, the presumably preferable coloration that transformers provide will be limited, as that results from transformer saturation, and saturation will be much lower with input tranfos since a mic signal is much lower than the line level signal coming after the preamp gain stage.  So if you're looking for additional gain and lower noise performance (neither of which really apply for concert PA recording, more like nature recording), you'd want input transformers.  If you want the euphonic transformer sound/coloration, you'd want output transformers.

I'd recommend output transformers that are switchable, so you can choose to use them or not (which is what I have on my littlebox).
« Last Edit: January 18, 2011, 02:32:20 PM by jmbell »
Microtech Gefell M20's> Nbob KCY> Naiant PFA(60v) > Sound Devices Mixpre-6 @24/48

-22        -12         -6        TDS     
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][}   
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][} 
__________________________
|Record|  Runtime: 4:19.99  {|||] 75%

Offline Todd R

  • Over/Under on next gear purchase: 2 months
  • Trade Count: (29)
  • Needs to get out more...
  • *****
  • Posts: 4889
  • Gender: Male
Re: Naiant Littlebox questions???
« Reply #8 on: January 18, 2011, 12:01:08 PM »
I could've sworn the standard gain was 32db, so I checked the Naiant website:  it is 32db, but it also starts at 6db gain, not 0.  So the standard gain range is 6-32db, with the optional input transformers, that would be an 18-44db gain range.  Again though, check with Jon, maybe he reduces the gain from the op amp gain stage to adjust for the 12db gain from the tranfos.

Also, I don't really think the issue is overloading the input, from Naiant's published specs, even a hot mic fed into a input-tranfo littlebox at deafening concert levels will not overload. The downside from what I see is Jon's own testing that shows that "professional" mics with a 400 ohm impedance will have a 10db rolloff of 20hz bass frequencies when using input transformers.  As Jon notes, this will be somewhat less for more typical 250 ohm impedance mics, but still the downside of input transformers is a loss of bass.  And if you want the "transformer sound", you'd get that more from output transformers.

I'm really just parroting back what Jon has said if you dig through his posts, but the summary seems to be:  if you want high gain, low noise amplification (like for nature recording or foley effects gathering), get input transformers; if you want that transformer sound, get output transformers.
Mics: Microtech Gefell m20/m21 (nbob/pfa actives), Line Audio CM3, Church CA-11 cards
Preamp:  none <sniff>
Recorders:  Sound Devices MixPre-6, Sony PCM-M10, Zoom H4nPro

Offline jbell

  • TDS
  • Trade Count: (143)
  • Needs to get out more...
  • *****
  • Posts: 4167
  • Gender: Male
  • Spreadicated
Re: Naiant Littlebox questions???
« Reply #9 on: January 18, 2011, 01:22:33 PM »
I stand corrected!  Thanks for the info. Jon
Microtech Gefell M20's> Nbob KCY> Naiant PFA(60v) > Sound Devices Mixpre-6 @24/48

-22        -12         -6        TDS     
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][}   
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]][} 
__________________________
|Record|  Runtime: 4:19.99  {|||] 75%

Offline F.O.Bean

  • Team Schoeps Tapir that
  • Trade Count: (126)
  • Needs to get out more...
  • *****
  • Posts: 40716
  • Gender: Male
  • Taperus Maximus
    • MediaFire Recordings
Re: Naiant Littlebox questions???
« Reply #10 on: January 18, 2011, 04:25:28 PM »
Todd is correct with respect to gain, it is 18dB - 44dB with input transformers in the circuit.  Also, the bass rolloff is dependent upon the source impedance of the microphone.

The input transformer cannot "clean" noise, but it can reduce interference because it has better common-mode rejection than the amplifier itself (70dB vs. 50dB).  Still, if you need more than 50dB of common-mode rejection, you are probably in a very bad situation to begin with; unfortunately the transformers are subject to picking up low-frequency EMI even though they are shielded.  So don't use them next to a power transformer . . .

The input transformers do reduce "equivalent input noise", which is a fancy way of saying that they give you mostly noise-free gain, such that the input signal gets louder before it gets mixed with the amplifier's noise.

I generally would not recommend input transformers for loud concert recording: -40dBV/Pa +(114dBSSPL - 94dBSPL) + 18dB gain = -2dBV, that's an average level though, peaks in program material could be 15dB or even 20dB higher.  That's still within littlebox's headroom, but you would have to check your recorder's spec.

John, so what would you suggest in me doing for loud concert recordings ??? I would like BOTH input and output tformers, but if you think I should just get output tformers then I'll take your word for it.

All I want out of this preamp is a nice clean sound but WITH color so I have a diff flavor then just MBHO>722. I am mainly using it at indoor venues, because most indoor venues have too much high-end/trebble, and I want to eliminate some of that high-end and come out w/ a somewhat more balanced sound :)
Recording Gear:
Schoeps MK 4V & MK 41V ->
Schoeps 250/0 KCY's ->
Naiant +60v/Low Noise PFA's ->
DarkTrain Right Angle Stubby XLR's ->
Sound Devices MixPre-6 & MixPre-3 ->
SanDisk 128gb Extreme Pro & 64gb Ultra Plus SDXC-I

Portable Playback Gear:
Campfire Audio Dorado IEM's >
Linum G2 SuperBax & Bax {3.5mm} | 
FiiO LC 2.5c {2.5mm} >
Shanling Audio M5s | Sony NW-A35 DAP's

DAW:
Dell Inspiron 15 5570-5521 Laptop

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline OOK

  • Trade Count: (17)
  • Needs to get out more...
  • *****
  • Posts: 2728
  • Gender: Male
  • formerly OtherOneK
Re: Naiant Littlebox questions???
« Reply #11 on: January 18, 2011, 05:55:22 PM »
unfortunately transformers are subject to picking up low-frequency EMI even though they are shielded.  So don't use them next to a power transformer . . .


Well you answered one question for me (gain)... 

next

Is the above true of both input and output transformers ........?

Thanks OOK
DPA/HEB 4060's > R09HR
MBHO648/KA100Lk/KA200/KA300/KA500 > SD702

Offline F.O.Bean

  • Team Schoeps Tapir that
  • Trade Count: (126)
  • Needs to get out more...
  • *****
  • Posts: 40716
  • Gender: Male
  • Taperus Maximus
    • MediaFire Recordings
Re: Naiant Littlebox questions???
« Reply #12 on: January 18, 2011, 07:09:16 PM »
unfortunately transformers are subject to picking up low-frequency EMI even though they are shielded.  So don't use them next to a power transformer . . .


Well you answered one question for me (gain)... 

next

Is the above true of both input and output transformers ........?

Thanks OOK

So what does that mean to you ???
Recording Gear:
Schoeps MK 4V & MK 41V ->
Schoeps 250/0 KCY's ->
Naiant +60v/Low Noise PFA's ->
DarkTrain Right Angle Stubby XLR's ->
Sound Devices MixPre-6 & MixPre-3 ->
SanDisk 128gb Extreme Pro & 64gb Ultra Plus SDXC-I

Portable Playback Gear:
Campfire Audio Dorado IEM's >
Linum G2 SuperBax & Bax {3.5mm} | 
FiiO LC 2.5c {2.5mm} >
Shanling Audio M5s | Sony NW-A35 DAP's

DAW:
Dell Inspiron 15 5570-5521 Laptop

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

Offline goodcooker

  • Trade Count: (36)
  • Needs to get out more...
  • *****
  • Posts: 3287
  • Gender: Male
  • goes to 11
Re: Naiant Littlebox questions???
« Reply #13 on: January 19, 2011, 02:40:48 AM »
I want to eliminate some of that high-end

MBHOs are pretty bright sounding mics...putting a transformer based preamp behind them is not going to change that.
Joly Mod Oktava MK012 C,H,O > Tascam DR701d


http://www.archive.org/bookmarks/goodcooker

"Are you the Zman?" - fan at Panic 10-08-10 Kansas City

"I don't know who left this perfectly good inflatable wook doll here, but if I'm blowing her up, I'm keeping her." -  hoppedup

Offline F.O.Bean

  • Team Schoeps Tapir that
  • Trade Count: (126)
  • Needs to get out more...
  • *****
  • Posts: 40716
  • Gender: Male
  • Taperus Maximus
    • MediaFire Recordings
Re: Naiant Littlebox questions???
« Reply #14 on: January 19, 2011, 10:43:12 PM »
I want to eliminate some of that high-end

MBHOs are pretty bright sounding mics...putting a transformer based preamp behind them is not going to change that.

Why not ??? Isnt that what tformers do ??? They add distortion to the low-end, correct? Which would in turn add a little lowend and take away some of the high-end emphasis
Recording Gear:
Schoeps MK 4V & MK 41V ->
Schoeps 250/0 KCY's ->
Naiant +60v/Low Noise PFA's ->
DarkTrain Right Angle Stubby XLR's ->
Sound Devices MixPre-6 & MixPre-3 ->
SanDisk 128gb Extreme Pro & 64gb Ultra Plus SDXC-I

Portable Playback Gear:
Campfire Audio Dorado IEM's >
Linum G2 SuperBax & Bax {3.5mm} | 
FiiO LC 2.5c {2.5mm} >
Shanling Audio M5s | Sony NW-A35 DAP's

DAW:
Dell Inspiron 15 5570-5521 Laptop

http://www.archive.org/bookmarks/diskobean
http://www.archive.org/bookmarks/Bean420
http://bt.etree.org/mytorrents.php
http://www.mediafire.com/folder/j9eu80jpuaubz/Recordings

 

RSS | Mobile
Page created in 0.149 seconds with 56 queries.
© 2002-2020 Taperssection.com
Powered by SMF