Topic: NJB3 as analog recorder: not very good! Diginoise on gain + hard drive noise

[poorlyconditioned]

I was curious about using the NJB3 as an analog recorder.  It seems like a good idea until I looked at the following picture:


I ran the NJB3 for three minutes, line input, 44.1k/16bit.  The first minute was at zero gain, the second at +6dB and the third minute at 12dB gain.  It appears to do gain *after* the ADC, as the noise gets larger.  Also, there appears to be some kind of high pitched hard drive noise every 20sec of so.

Is this in the FAQ? I remember dklein did some analysis, but I don't think I ever saw hard drive noise listed.  Anyway, if you can tolerate 60-70dB SNR the NJB3 might be fine, but I'm not very happy with this!  The NJB3 rules for digital recording though...

  Richard

[The Kilted Taper]

Hard drive noise has been talked about lots. When actually using it at a show, i't usually drowned out by the music, so it's not a huge issue. Some folks have it worse than others. I haven't had any issues using it as an analog recorder at all.

[dlandis]

My experience using the JB3 as an analog recorder has been excellent also. However, I have noticed the same picture posted above when working with the files in Sound Forge v6.0. My ears do not pick up the HDD noise, though. It could very well be there, I just don't notice it. One of the positives of having a lo-fi playback system and bad hearing, I guess. ;-)

Don

Equipment: SP-BMC-6 mics (AT803b) > SP-SPSB-1 battery box > Nomad JB 3.

[poorlyconditioned]

My experience using the JB3 as an analog recorder has been excellent also. However, I have noticed the same picture posted above when working with the files in Sound Forge v6.0. My ears do not pick up the HDD noise, though. It could very well be there, I just don't notice it. One of the positives of having a lo-fi playback system and bad hearing, I guess. ;-)

Don

Equipment: SP-BMC-6 mics (AT803b) > SP-SPSB-1 battery box > Nomad JB 3.

Yeah, I'm not trying to dis the NJB3.  This is a rare gem in the world of retail audio.  But it makes me consider going back to minidisc (HiMD with PCM recording) for analog stuff.  It is a shame since I'm really loving the fast firewire transfers and  3hr record time!

  Richard

[kgreener]

check out the info on yahoo groups regarding this subject:

http://groups.yahoo.com/group/njb3tapers/files/

[spyder9]

I had this experience.  I got a preamp (Denecke AD20) and my problem was solved.  Its not about analog, its about not having enough gain coming into the JB3.  The JB3's on-board gain doesn't cut it.  You could also use a Sound Devices MP2 or Shure FP24 ( re-badge MP2) and they will provide the necessary gain.  This eliminating that god awful 20 second HD noise.

The ADC converter on the JB3 is not the greatest either, but sufficient.  If your stealthing, Denecke AD20 or a Sanosax SX-M2 are fantastic as ADs and preamps.

[poorlyconditioned]

I'm not clear on the source that you're feeding the Line-in.  Was it from a mic/battbox or from a line signal source?  In either case, I've used mics (AT853 or ES943)>batt box>JB3 many times and never gotten a wav pattern that you show.  I'd look to the signal chain as a culprit for that noise or perhaps a deffective analog circuit in the JB3.  IMO, it's not something that is typical of analog recording as a rule so don't give up on it.  Good luck

This was with no input connected.  I guess I should have shorted the input (or put a resistor across it) instead.  Anyway, I'm making two points.  First, whatever noise was there, it seemed to double in voltage each time I doubled the gain (ie., 6dB).  Second, there is this periodic blip, probably due to hard drive seek noise, but I'm not sure.

I would love it if these things went away, but I don't think they will.  I'm not saying you will hear them for concert recordings, but for all our fussing about gear on this forum it would be a shame to rely on an analog input that is screwed up!

  Richard

[tms]

Were you running an external power supply at the time?  Or battery power?  It makes a _BIG_HUGE_  difference.

Try recording both ways.  For mine (and maybe they're all different) I get a lot of clicks, pops, and beeps when recording analog line-in with any external power supply attached.  The noise is worse at higher gain.  I would never record analog while feeding any external power into the +5V port.

These noises disappear when running battery power only. 

Can you try it again and report back?

Todd in Buffalo

I was curious about using the NJB3 as an analog recorder.  It seems like a good idea until I looked at the following picture:


I ran the NJB3 for three minutes, line input, 44.1k/16bit.  The first minute was at zero gain, the second at +6dB and the third minute at 12dB gain.  It appears to do gain *after* the ADC, as the noise gets larger.  Also, there appears to be some kind of high pitched hard drive noise every 20sec of so.

Is this in the FAQ? I remember dklein did some analysis, but I don't think I ever saw hard drive noise listed.  Anyway, if you can tolerate 60-70dB SNR the NJB3 might be fine, but I'm not very happy with this!  The NJB3 rules for digital recording though...

  Richard

[Karl]

Recording analog in isn't really a problem for those who tape bands and stuff, but it is a problem for people who tape acoustic stuff.  Like orchestra, or anything that's not amplified, or has lots of loud/quiet sections.

To compensate for a few bad recordings I made before I got a preamp, is I used wave plug-ins to get rid of that high-pitched hard drive noise.

Another thing that is not really mentioned in other threads about this problem--if you are running analog in on the jb3, and the backlight is on, it adds ANOTHER high pitched noise to the recording.

[aberg]

Recording analog in isn't really a problem for those who tape bands and stuff, but it is a problem for people who tape acoustic stuff.  Like orchestra, or anything that's not amplified, or has lots of loud/quiet sections.

To compensate for a few bad recordings I made before I got a preamp, is I used wave plug-ins to get rid of that high-pitched hard drive noise.

Another thing that is not really mentioned in other threads about this problem--if you are running analog in on the jb3, and the backlight is on, it adds ANOTHER high pitched noise to the recording.

What plugin did you use to eliminate this noise?

[Karl]

Waves Q10 (or Q4) paragraphic EQ.  Settings:

Use bell shape eq.
Start at -6 dB
Freq: 8415 Hz
Q: 100 (narrow as possible)

If this is the route your going to go, check to make sure that your freq is right for where your noise is coming from.  To do that, select part of the music where you can hear the HD noise. Start with the settings above--but pull the dB up to +18.  Then use the mouse to slowly move the freq to the left then right--when you hear the noise the loudest then you know you've nailed the freq.  Then pull the gain back down to -6dB.  You may want to go to -9 or even -12 dB to get rid of the noise--but keep in mind, the more you go the more wanted frequencies you take out of the music.

[mmmatt]

Were you running an external power supply at the time?  Or battery power?  It makes a _BIG_HUGE_  difference.

Try recording both ways.  For mine (and maybe they're all different) I get a lot of clicks, pops, and beeps when recording analog line-in with any external power supply attached.  The noise is worse at higher gain.  I would never record analog while feeding any external power into the +5V port.

These noises disappear when running battery power only. 

Can you try it again and report back?

Todd in Buffalo

I was curious about using the NJB3 as an analog recorder.  It seems like a good idea until I looked at the following picture:


I ran the NJB3 for three minutes, line input, 44.1k/16bit.  The first minute was at zero gain, the second at +6dB and the third minute at 12dB gain.  It appears to do gain *after* the ADC, as the noise gets larger.  Also, there appears to be some kind of high pitched hard drive noise every 20sec of so.

Is this in the FAQ? I remember dklein did some analysis, but I don't think I ever saw hard drive noise listed.  Anyway, if you can tolerate 60-70dB SNR the NJB3 might be fine, but I'm not very happy with this!  The NJB3 rules for digital recording though...

  Richard

I've noticed this as well.  When using my hacked car charger going v2>jb3 I get some noise and the pops described, but when using the internal battery I get nothing.  Since my current jb3 only has 1 internal, I have since taken to charging the battery with my car charger between sets instead of actually running off the charger.  I have not ever noticed this however when running off of regular ac power... just the car charger.  I thought it was the hacked charger but maybe I should listen closely for noise on wall power as well.

Matt

[aberg]

Wow, that's good to know. I was definitely using external power when I noticed the issue.

[jkoch]

Wow, that's good to know. I was definitely using external power when I noticed the issue.

same deal. i pick up clicks/pops when using external power. nada with internal batts

[tms]

I've noticed this as well.  When using my hacked car charger going v2>jb3 I get some noise and the pops described, but when using the internal battery I get nothing.  Since my current jb3 only has 1 internal, I have since taken to charging the battery with my car charger between sets instead of actually running off the charger.  I have not ever noticed this however when running off of regular ac power... just the car charger.  I thought it was the hacked charger but maybe I should listen closely for noise on wall power as well.

Matt

Actually I never tried it with the Creative AC charger.  Just a DC cig adapter at 4.5V and a LM7805 homemade power supply.  I too have to charge between sets.  Fortunately that thing charges like a motha-focka!  Just a few minutes of charging really goes a long way.

So I guess there are 3 tests to try, AC charger, battery, and cig adapter.