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

[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!