Topic: JB3 hd noise = audible on recording? + preventing shutdown!

[bmr]

I bought a few refurbed JB3s a few months back, and sent one to a buddy in australia. He ran CSCs > SP bbox > JB3 for his first JB3 show last night, but had two major problems which are driving him nuts...and since I sold him the JB3, I feel I have a bit of a moral obligation to help him get to the bottom of this for him. Hopefully wiser heads here can help...

1) When familiarizing himself with it, and taping his stereo at home with his rig, he was able to cleanly hear the JB3's hard drive spin up on the resulting wav file upon playback. His mics were far enough away for it to where it wasn't being picked up by them; it had to be generated internally, he said. He then went 1/8" > 1/8" from the stereo's headphone out > JB3 line in, recorded for a while, and not once did he hear the sound. He sent me a sound clip from the show he recorded last night, where it's definitely audible, and is definitely the hard drive's noise.

Is it a common thing to be able to hear the hd spin on a recording? And why would it only do it with the mics > bbox and not the 1/8" line signal? I run optical into the JB3, so I haven't experienced this...but I also haven't heard my hard drive ON my recordings, either...any idea what's going on here? Anything he could do to lose the noise?

---

2) He was "1000% sure" that he button-locked the JB3 during his recording, yet it continually shut down on him while recording. He selected "continuous" on the "Record Settings" screen, though I told him I'm pretty sure that refers to the length of the wave file and doesn't have to do with power. He kept it in a large jacket pocket, which he said wasn't hot...and after the FIFTH time it shut down on him, he held it in his hand and hit the scroll wheel every minute or two to manually keep it active.

Is there anything he needs to be doing other than set the button lock? I button-lock my JB3, but I also (in Settings > Edit Profile) set "sleep timer" and "idle timer" to "off" since I'm not exactly sure where/when those take effect.

I'm just really worried I may have shipped him a lemon...when he returns home this evening, he's going to run his rig again and record, to see if he notices if it shuts off at a specific time or something like that.

Any ideas?

[hexyjones]

What kind of noise is it...? Can you describe...?

[bmr]

What kind of noise is it...? Can you describe...?

Turn on your JB3, and put your ear next to the bottom of the unit...that spinning up sound is what's on the recording.

[hexyjones]

What kind of noise is it...? Can you describe...?

Turn on your JB3, and put your ear next to the bottom of the unit...that spinning up sound is what's on the recording.

Hmm...I wonder if this problem is similar to "cable handling" thumping noise that can sometimes occur with unbalanced lines or shoddy connections...

[Sanjay]

the pocket may not be hot, but it still can shut down, i have had this happen one too many times for my liking.  As for the HD noise it either has to be his battery box picking up the noise from the HD (is that even possible?) or his mics are too close, because if it records through line-in correctly from the stereo with no noise it shouldnt be a nomad problem.

[Swampy]

Ya, I think in the past some people have talked about HD noise on analog ins on the JB3... I not sure why it happens, but Id be interested to find out too.

[hexyjones]

I might add...one of my JB3s is incredibly sensitive to heat...so not all units are the same...

I wonder if all jb3s ship with the same hard drive?...maybe some have shit drives in them?

[hhf32]

What you have is normal for a JB3.  I've written about this a few times.  You get some bleed into the analog circuits from the hard drive activity - as I recall it alternates at 5 sec/10sec intervals.  If your source signal is high enough, it is not audible.  If your source is low and you need to crank the volume or boost with software, it becomes audible.

This, along with the pre-amp self noise and quality, is why some people elect to use external pre/a>d boxes.

What are you plugging into the JB3 and what recording settings are you using (mic-in / line-in and gain settings)?

You reported "noisy recordings" - let's hear one.

This sounds kind of what your experiencing. I remember reading this awhile back, do an advanced search and there's alot on the subject.

[hexyjones]

What you have is normal for a JB3.  I've written about this a few times.  You get some bleed into the analog circuits from the hard drive activity - as I recall it alternates at 5 sec/10sec intervals.  If your source signal is high enough, it is not audible.  If your source is low and you need to crank the volume or boost with software, it becomes audible.

This, along with the pre-amp self noise and quality, is why some people elect to use external pre/a>d boxes.

What are you plugging into the JB3 and what recording settings are you using (mic-in / line-in and gain settings)?

You reported "noisy recordings" - let's hear one.

This sounds kind of what your experiencing. I remember reading this awhile back, do an advanced search and there's alot on the subject.

I follow that...but I've never heard it...I just stealthed a show in a theatre. Used a stereo mic...line in..used all 12db of gain. The recording only came out at like 10%...I had to add like 20 something db of gain. On the final boosted version, between songs I can hear the line in noise...almost like analog tape...just a bit higher freqency. But I havent heard anyting that sounds like drive movement.

Thats why I wondered if these things all had the same drives....? Maybe some arent as well sheilded?

[Humbug]

Apologies if anyones read similar from me before...I've made somwehere around 100 stealth recordings now with two different Nomads. Always kept in jacket pocket, sometimes taken out while recording to give them some air.

Nomad #1 (new April '03) has been reliable 95% of the time, shutting down only under extreme conditions (lots of heat, people bumping into me). One time I was almost knocked over by a bouncer pulling out someone who had fainted, and that was the exact same moment it shut down. Running 1.20.06. Seems to run hotter than #2.

Nomad #2 (refurb) arrived a month ago and has been used around 10 times, but not under extreme conditions. 100% reliable so far. Running 1.40.06.

The testing continues, and I'm not changing this little box for anything right now...neither am I taking them both apart to see what hard drive is in there, I'd never get it back together!

[The Kilted Taper]

I will agree with some of the others on the shutdown issue, that is is probably heat created. The pocket may not be hot, but these units generate a good amount of heat and need to be able to "breath".  If at all possible, attach a belt clip to the back so it can be worn and get air. I have one of those pleather cases that has a clip on the back that I attach to my belt while stealthing. I'll cover it up with my unzipped hoody and just lift up the hoody occasionaly to let it breath. No problems yet (knock on wood  )

[hexyjones]

I will agree with some of the others on the shutdown issue, that is is probably heat created. The pocket may not be hot, but these units generate a good amount of heat and need to be able to "breath".  If at all possible, attach a belt clip to the back so it can be worn and get air. I have one of those pleather cases that has a clip on the back that I attach to my belt while stealthing. I'll cover it up with my unzipped hoody and just lift up the hoody occasionaly to let it breath. No problems yet (knock on wood  )

Well with mine it's a "Start Up" Issue...if it's a warm day and I let the deck get even a tiny bit warm before I turn it on...it wont start...I really have never had it shut down...once it locked up. Once the power blew at a show and it took a few minutes before it would start up...but as long as it's cool...no problem. Glad fall/winter is here...well not so glad since I got second nomad that seems to work a little better...

[Karl]

I can address the issue of the noise that you are hearing--yes, it is noise created by the hard drive spinning.  I ran into lots of problems with it at first, because I had to tape for about a year with just mics>bb>jb3.  I taped a lot of classical type material, with a wide range of dynamics, so in the quiet sections you would hear that nasty hum from the HD spinning.  It's nothing that a good preamp and/or external a/d could take care of.

What I noticed was that about every 18 seconds (recording at 44.1k) you would hear the HD hum.  The reason you hear it is this--there are multiple clocks etc running on the jb3, and they all create what's called RF interference--basically radio waves.  When the hard drive spins, it creates a frequency that mixes with other frequencies to equal frequencies that are in our audible hearing range.  Because the innards of the jb3 are not that well shielded, they easily pick up those frequencies, and it gets recorded as audio.

What I ended up doing to save those recordings was to identify the frequency of the hum (I think it was just above 8kHz) and deleted just that frequency.  Though, that should prob only be done with wave editors that work in 32 bit (float) format, and even there you may notice some artifacts.

If you primarily tape music that is loud (and constantly loud) then you can get away with using mics>bb>jb3, because the music will cover up that humming noise.

[Karl]

jk, check your pm's

[Brian Skalinder]

jk, check your pm's

Am curious to see the response to JKL's question posted publicly, if you're willing.

[dklein]

The noise corresponds to hard drive writes.  To the best of my memory, it occurs every 9 seconds, alternating between single and double high pitched 'beeps' that become audible during quiet portions if some post gain is applied (or if your source was very quiet). 

The JB3 buffers data and then writes, quite frequently when your recording wave and much less on mp3.  The write seems to cause noise in the analog...my guess is thru the power supply.  Running an ammeter on the JB3 shows each write is a big power sucker (which is also how I correlated the noise to the write event).

This all goes away with optical connections.

[Humbug]

I dunno if this helps, but 95% of the stuff I record is loud rock music.

However the remaining 5% is acoustic, minimally ampified.

I've never heard any artefacts whatsoever in my recordings, either on the acoustic stuff or between tracks at the rock gigs.

Cheers

Humbug

[dklein]

well if you want to hear it, just record line-in without anything attached to the JB3.
Turn up the volume on playback (of course it's louder if you set the JB3 to +12dB when recording)

Once you've heard it you'll know when you hear it again...

[spyder9]

Dudes,

The HD drive problem is simple:  Get a Preamp!  I had the same problem with the HD noise ( mini mics > battery box > JB3).  Once I got a Denecke AD-20, problem solved.  The preamp will bring the recording up to line level.   

[Brian Skalinder]

The HD drive problem is simple:  Get a Preamp!  I had the same problem with the HD noise ( mini mics > battery box > JB3).  Once I got a Denecke AD-20, problem solved.  The preamp will bring the recording up to line level.   

Well, in your case you got a preamp *and* ADC.  A preamp alone *should* get levels up to the point (line-level) where the noise is inaudible, but my understanding from David Klein's testing is that the noise is still there - just inaudible.

[spyder9]

Well, in your case you got a preamp *and* ADC.  A preamp alone *should* get levels up to the point (line-level) where the noise is inaudible, but my understanding from David Klein's testing is that the noise is still there - just inaudible.

Inaudible.  Enough said.   

[Brian Skalinder]

Inaudible.  Enough said.   

Not enough said. 

I haven't done the testing, so I don't know for certain if it'd be inaudible on my system with my ears.  I'm nitpicky that way - won't believe it as 100% fact unless I've done it myself.  But on this one, I'm not gonna put the time in to test so I trust David's tests. 

That said, inaudible to some is not inaudible to others.  I've hosted enough blind comparisons here to know that different people hear different things from the same sources.  Not saying David's not correct - for his recording / playback / ears - just that every situation is different.

And even if it's inaudible now, it may become audible after processing.  For example, compressing my recording to reduce dynamic range and then raising levels to get my peaks back up.  Doing so would, of course, raise the relative noise level.

[spyder9]

I actually listen to all my shows through canalphones while taping.  Haven't heard a peep.  Even during the quietest moments between songs.  And I squint to listen for anamolies.  I think anymore time put in beyond adding a preamp would be neurotic.  That's just my opinion.

[dklein]

I'll add that 'inaudible' really depends on what you're listening to.  You might not hear it during the music, but you could between songs if the crowd is quiet.  The hard drive noise peaks at -70 dB or so when the JB3 is set to line-in, 0 dB.

As far as using mics go, the attached sample is the noise you get at the +12 dB setting with 20 dB of gain in post (that's a total of 32 dB).  That's probably typical for a real low sensitivity mic.  Whether or not your music drowns it out depends on what you're recording.

If you can drive proper line level signals with a preamp and leave the JB3 at 0 dB, then this sound is down 70 dB which I think we can probably call inaudible, but as Brian says - prove it for yourself.

[dklein]

Here's part of another sample I just posted to the NJB3 tapers group.  This is using CSB>JB3, line-in +12 dB with post gain of 23 dB.
2 parts - the silence b/w songs and then the beginning of a song where it is audible over the music.

[spyder9]

I'll add that 'inaudible' really depends on what you're listening to.  You might not hear it during the music, but you could between songs if the crowd is quiet.  The hard drive noise peaks at -70 dB or so when the JB3 is set to line-in, 0 dB.

As far as using mics go, the attached sample is the noise you get at the +12 dB setting with 20 dB of gain in post (that's a total of 32 dB).  That's probably typical for a real low sensitivity mic.  Whether or not your music drowns it out depends on what you're recording.

If you can drive proper line level signals with a preamp and leave the JB3 at 0 dB, then this sound is down 70 dB which I think we can probably call inaudible, but as Brian says - prove it for yourself.

Thank you for all your efforts.  You gave me advice back in June regarding this "noise."  I went w/ the AD20 and have not heard the "noise" again.  Could you post the same sample but with the AD20 wedged in there.  I think that will be a fair comparison.  If you can't, I will after the holiday.

[Brian Skalinder]

I went w/ the AD20 and have not heard the "noise" again.  Could you post the same sample but with the AD20 wedged in there.

No test needed if you're concerned about JB3 gain stage and ADC noise, since the AD20 provides gain and A>D outside of the JB3.  The noise is only an issue when the gain and ADC are performed inside the JB3.  The only noise you should hear with the AD20 in the chain is the noise from your mics - self-noise, noise in the surrounding environment, etc.  But none from the JB3.  Make sense?

[spyder9]

Precisely. I think I said that above, but not in those words. 

Battery box people, just get a preamp.  UA5, Denecke AD20, etc.  It will eliminate the HD noise from your recordings.

Happy Thanksgiving Brian.

[Brian Skalinder]

Precisely. I think I said that above, but not in those words.

No no no.  Forgive me for continuing to harp, but it's important to get this right.  I believe we're saying the same thing.  However...

Battery box people, just get a preamp.  UA5, Denecke AD20, etc.  It will eliminate the HD noise from your recordings.

The UA5 and AD-20 both contain a gain stage (preamp) and an ADC.  A preamp alone will not remove the sound.  It may minimize the noise by making it quieter relative to the stronger musical signal, so much so that the recordings are good enough for an individual's taste, but it won't *remove* the noise.  Only an external ADC will remove the noise outright.

So, there are really two statements we can make here, expanding on your quote above:

[1]  Battery box people, just get an outboard preamp to minimize* the HD noise for most recordings.
[2]  Battery box people, just get an outboard preamp *and* ADC to remove the noise completely.

*  Render inaudible?  Depends, I suppose, I haven't done the testing myself

My whole point, and maybe I'm just getting caught up in semantics (wouldn't be the first time!):  to suggest that an outboard preamp alone removes the noise is incorrect.  To remove it entirely requires an outboard ADC.

And backatcha:  Happy Thanksgiving!!

[spyder9]

T+, Brian is correct!

[hexyjones]

Inaudible.  Enough said.   

Not enough said. 

I haven't done the testing, so I don't know for certain if it'd be inaudible on my system with my ears.  I'm nitpicky that way - won't believe it as 100% fact unless I've done it myself.  But on this one, I'm not gonna put the time in to test so I trust David's tests. 

That said, inaudible to some is not inaudible to others.  I've hosted enough blind comparisons here to know that different people hear different things from the same sources.  Not saying David's not correct - for his recording / playback / ears - just that every situation is different.

And even if it's inaudible now, it may become audible after processing.  For example, compressing my recording to reduce dynamic range and then raising levels to get my peaks back up.  Doing so would, of course, raise the relative noise level.

Dont assume this condition is present in EVERY jb3...we need to do a survey about what kind of harddrives are in these things...I think we may find a certain combo that induces noise...

[Brian Skalinder]

Dont assume this condition is present in EVERY jb3...we need to do a survey about what kind of harddrives are in these things...I think we may find a certain combo that induces noise...

True enough, it wouldn't surprise me in the least of Creative dropped different HDs in different units over the years.  I'm reluctant to crack my case, though - too paranoid about breaking something in the process (I'm mostly thumbs).

[Karl]

Precisely. I think I said that above, but not in those words. 

Battery box people, just get a preamp.  UA5, Denecke AD20, etc.  It will eliminate the HD noise from your recordings.

Happy Thanksgiving Brian.

That's good and all, but what about the people who are on a budget who can't quite yet afford to upgrade to a preamp and/or ADC?

[dklein]

Dont assume this condition is present in EVERY jb3...we need to do a survey about what kind of harddrives are in these things...I think we may find a certain combo that induces noise...

All you gotta do is record a minute of line-in without hooking up any mics or anything.  Pop the wave file into an editor and run the analysis on it.  It will tell you how loud the noise is.  The noise follows an 18 second cycle in my machine.  Peaks are around:
-70 dB with line-in at 0dB
-55 dB with line-in at +12 dB

edit to fix up my sloppy quoting

[hexyjones]

Dont assume this condition is present in EVERY jb3...we need to do a survey about what kind of harddrives are in these things...I think we may find a certain combo that induces noise...

All you gotta do is record a minute of line-in without hooking up any mics or anything.  Pop the wave file into an editor and run the analysis on it.  It will tell you how loud the noise is.  The noise follows an 18 second cycle in my machine.  Peaks are around:
-70 dB with line-in at 0dB
-55 dB with line-in at +12 dB

And what version of the firmware are you using...?

[Brian Skalinder]

That's good and all, but what about the people who are on a budget who can't quite yet afford to upgrade to a preamp and/or ADC?

Decide by actual usage (i.e. don't take someone else's word for it) whether or not the noise is sufficient enough to *your ears* to consider other alternatives.  And if the noise is a problem to your ears, pursue alternative recorders, at this stage DAT or Hi-MD.

[dklein]

And what version of the firmware are you using...?

Good point - 1.32.02

[FINCHY]

Sorry I got here VERY late! First of all: THANK YOU SOOOO MUCH to everyone who has posted here with your knowledge/experience/expertise/opinions etc.

I am the dude in Brisbane (Australia) that bmr referred to in the first post, I am new to the JB3 world (had mine 8 days), but I've been taping for 2 years previously on MD. My current rig is: Coresound Cardioids > SP 9V Battery Module (w/ Bass Rolloff disabled) > NJ3 Line-In. Anyway...

I taped Xavier Rudd last Sunday as my first show on the JB3, as bmr said it was continuously shutting down on me, & I was getting the hard drive noise every 8-10 secs but only in patches here & there, but its definitely enough to spoil the recording.

I taped another show (Carus & Joseph Parsons) on Wed night at a much smaller venue & the NJ3 only powered down 3 times (the NJ3 this time was in my new cd-player bag with shoulder strap just hanging in front of my belly). After the first 2 times it shut down I took it out & sat it on the table where I was sitting so that it could have some open breathing air (as I had suspected that it was heat related probs). I got another 25-30mins recorded & the unit STILL shut down again!! & it was not a hot atmosphere... so I'm a little stumped on that one. But I do have a feeling that the issue is heat related & just cutting out. Obviously very disappointed about it, but I need to resolve the issue, & although taping might be much more open & acceptable in the States, here in Oz in most venues & situations (even if the band is taper friendly) the recording needs to be conducted in a very stealth manor!!! - Which means that I can't always just have my NJ3 out in the open (in fact VERY rarely could that happen).


Anyway I would love some feedback on an idea I had about using some sort cold/gel-pack thing. You know those thin soft blue gel pack, if I enclosed the NJ3 in 1 of those along with something like paper towelling to stop or absorb any possible moisture. Surely that would help to keep the unit cooler & hopefully help to stop it powering down.

Other idea I had was to dismantle the NJ3 & find some appropriate places in the plastic casing to drill some very small holes to allow more ventilation. If heat is an issue for these units then it seems crazy not to have any air-hole ventilation!

& I know that having 2 batteries in the NJ3 is gonna make things worse (coz the batteries sit right against the hard drive almost), but sadly most of the time I'm gonna need the full power of both, I've only managed to get so far a full 5 hours from 2 batteries for recording (sometimes less) so 1 battery isn't gonna be enough for the marjority of shows I do. I would love to know any feedback or statistics of what other NJ3 users general use: 1 or 2 batteries??


So anyway: any further help/ideas/suggestions/feedback with solving the power-down issue would be sooo gratefully appreciated - I really need to fix this prob! I have a huge 6 day festival (Woodford Folk Festival) to tape in less than 4 weeks & I really have to get this shit sorted otherwise it might be back to the rotten MD again 

I wish I had of known of the inherent problems with using a BBox with NJ3 coz I just bought a brand new SP BBox for over US$70, & after buying the NJ3 & 2nd battery ontop (Plus international shipping etc) I really can't afford to get more expensive items: pre-amp & adc etc. I would like to go that way thou, & I would love to hear as many best recomendations as possible please! ??

As I said: stealthiness is a must for me so I can't really carry around big bulky units with additional power supplies etc etc. & from what Brian said how just getting a pre-amp will only effectively reduce the hard drive intereference noise & not remove it > then I really wanna go for an ADC to completely eliminate the noise all together!! I'm picky & cannot stand interference!. An ADC thats small, simple, & has its own internal power supply (if such a thing even exists!?). & I wanna stick with my CSC mics for now (coz I love em for what they do).

Anyway please everyone help me out further with any info, advice, & recommendations etc... I can't afford much but if there is a suitable ADC or other solution around then I will go that way & chop off a toe if I have to - to get it! I have looked arounda few sites mostly just the SP site, & I haven't found anything thats self powered, or reasonable size/price etc.

I really need to solve the 2 issues: power-down, & HD noise... in time for Woodford coz I wanna tape at least 20-25 shows over 6 days!

Thanks again for everything all you lovely people!!
Much love - Finchy

[Karl]

I think there's as much info as there is going to be about the HD noise problem in this thread--

But I think I may have some more light to shed on your power-down problem.  If you are experiencing heat-related problems, then your unit is faulty, and I wonder if you could get an exchange for it.  I live in Arizona, and haven't yet had a heat-related problem.  Like I said in a different thread, Creative's Q/A department sucks, so it would be no wonder the the wide variances in auto-shut off due to heat.

If you can't exchange the unit, and if you are good at taking things apart etc, then you might want to do some experimentation.  There is likely a thermistor somewhere in the innards of the JB3.  I suspect that you could find out where that is, and just replace it with a fixed-value resistor (thermistors change resistance with temperature change).  Or you could put a resistor in parallel or in series with the thermistor to extend the temperature range.  In parallel or series would depend on how the circuitry is set up in the first place.

Good luck!!!!

[John R]

i had mine shut down di=ue to heat a couple of times, but then just made sure it was not in the 'direct' sunlight, and everything was ok.  i'll be curious to see if the drilling makes a difference.  be sure to take and post plenty of photos

[Humbug]

This is a little harsh (but I hope fair) on the guy who sent you the jb3, but in my opinion, the JB3 is faulty.

Yes, JB3s can shut down under extreme conditions (eg stealthing in a pocket jacket, with pleatherette case fitted at a packed, hot and humid venue).

I'd say your unit definitely falls outside the acceptable limits for a JB3 though!