Topic: Troubleshooting JB3

[Karl]

If you have a JB3, you can help me out, especially if you are recording analog line-in.  I'm getting noisy recordings, and I'm not sure if I have a defective unit or all JB3's are this way.  Listen to this link:

http://www.public.asu.edu/~karldrum/jb3hum.wav

That recording was recorded with the line-in setting, gain at 0, with absolutely nothing attached to the recorder (mics, headphones, or powersupply).  It was recorded far away from anything that would cause a lot of external RF interference, ie my PC.  Listen especially for the harddrive whir at about :18 and :35.

Make sure you listen to it in an environment where you can really hear the recording.

Is anyone else having this problem???

[Kindguy]

I've tested my JB3 running line in at the house with no prob.

What firmware are you using?

Another prob I've heard is the line in plug not fitting in the JB3 all the way. Thus a bad connection. Search around & you'll find some threads about moding the imput area so the plug fits all the way in.

My at853's fit fine. fwiw

[Karl]

I'm using the 1.32.02 version, but I had the 1.40.06 (newest) installed, and had the same results.

For this testing purpose, I have nothing even plugged into the line-in jack.  Even when I have hooked up mics, I'm sure that the connection was good (it fit tight though).

Thanks.

I need some more feedback, please

[Ed.]

well i do hear it, however, i had to put on headphones and turn the computer audio all the way up to hear it.  my work speakers are crap tho, so that might explain it.  When i get home i'll try this out with my mics and see what happens.  I usually record loud concerts and that little noise would never show up, but i'll see what happens when its quiet.

[dklein]

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.

[dklein]

Hey  - just read your other post.  So your gear is:

AT853>batt box>Sharp DR-7 or JB3

You also reported you've "become rather unhappy with the noise that ATRAC compression introduces"

Now I'm really curious to hear a sample.  Is it possible that your mics may be funky or your battery box needs a fresh battery.

Maybe it's just the choice of words, but ATRAC shouldn't introducing any noise...

[Karl]

Thanks Ed and dklein, that's the response I was looking for.  Now I know it's a real problem and not a fluke.  This board rocks.

So yeah, dklein, that's basically my problem then, is I don't have a preamp (and can't get one right away) so I am stuck with either recording on MD or a jb3 with analog in that's probably a worse situation than recording with MD.  I might be able to get a DAT like was suggested on my other thread, but I'm really hesitant about DAT--the constant need to shell out cash for new tapes and batteries, the fact that DAT is slowly disappearing altogether, etc.  One way or the other, I don't see myself using DAT in the long run, so I don't want to invest in it right now.

As far as ATRAC goes--here's a basic rundown of what I do with my MD recordings.  I will transfer them to my computer via iMic (which offers a quite nice transfer, even though it's analog>USB).  I usually do some moderate editing in my computer, mostly eq and compression.  I will then burn the audio to CD and take it to my car, where I really have my best playback abilities--I have an Alpine deck, PPI amp, JL Audio component speakers.  Those tweeters are really honest (and brutal) about the quality of my recordings.  The "lossy compression" that people talk about with ATRAC becomes painfully obvious at that point.  You hear it in the high frequencies--especially cymbals.  It's not a gross ugly noise, it's kind of hard to describe, but it's there and not natural.  The cymbals shimmer more than they are supposed to.  The sound has a slightly grainy quality to it, if that makes sense.  And I am tired of hearing it in my recordings.  If I get the chance to post some recordings, I will.  Also, don't assume that's it's my audio software on my PC that's introducing the noise--the editing is all done with internal 32 bit precision.  And, even if I don't do any editing at all, I will still hear the same  noise by the time it gets to my car stereo.

[dklein]

Also, don't assume that's it's my audio software on my PC that's introducing the noise--the editing is all done with internal 32 bit precision.  And, even if I don't do any editing at all, I will still hear the same  noise by the time it gets to my car stereo.

Nope...but I might guess that your iMic conversion ain't doing it any good.  

You've got a lot of steps in your processing.  I'd start listening early in the chain and see where it appears:

• Do you hear it when you listen to the master on your md? (thru headphones, stereo or by plugging md into your car stereo).
• Do you hear it after the transfer (but before the processing) - plug headphones into your computer
• Same for post processing, still in 32 bit
• Same for post dithering (now in 16 bit and this could definitely be an issue)

pm me and I'll give you an ftp login if you want to upload a sample to me.  

And if you want to mail me a minidisc, I'd be happy to do a digital transfer and put it up on ftp for you.  It'd be one way of evaluating your current transfer method.

But back to your original post, you shouldn't be experiencing the same kind of problem with the JB3.
 What input and gain settings are you using on the JB3?

[Karl]

Ok, input and gain settings on the jb3:  I haven't made any "real" recordings yet with this, just ambient noise in my house.  But, recordings that I might make with my setup would require me to use the line input, and boost the gain 8-12 dB.  As for the recording in the above post, the gain is at 0, with the line input, with nothing attached to the line-in jack.

Another thing I realized--a lot of people on this forum probably record mainly jam bands, etc, which means you have a pretty loud sound that your recording continuously.  I record a lot of choir concerts, band concerts, etc etc where a lot of real quiet sounds are recorded--thus making the jb3 line-in with no pre-amp a very poor option.

As far as ATRAC goes--I'm not going to rule out that the iMic transfer might be introducing some problems.  But, I do hear the problems I'm describing when I listen to the recording with my computer speakers.  They are Boston Acoustics computer speakers, which have internal amps, and I'm driving it on the MD headphone jack.

Let's not worry about  the FTP just yet, I still have more webspace that I can put some stuff up.  But I might take you up on the offer to mail you an MD.

[Karl]

One thing I wanted to ask also--you seem confident that ATRAC isn't audible to the ears (and I hope your right, because that means I'm doing something wrong and I might be able to get some better recordings post-production).  Then, why the big deal about ATRAC being a lossy compression scheme?  If we can't hear it, then who cares?  (I'm asking in a sincere way--I hope that is not coming across as sarcastic, argumentative or overly rhetorical).

[Brian Skalinder]

One thing I wanted to ask also--you seem confident that ATRAC isn't audible to the ears (and I hope your right, because that means I'm doing something wrong and I might be able to get some better recordings post-production).  Then, why the big deal about ATRAC being a lossy compression scheme?  If we can't hear it, then who cares?  (I'm asking in a sincere way--I hope that is not coming across as sarcastic, argumentative or overly rhetorical).

It isn't that ATRAC compression isn't audible.  I believe what David is saying is it doesn't introduce noticable noise into the recording, like the noise you're experiencing.  ATRAC compression is definitely audible, just not noisy.

[teamakg]

pick up an optical convertor.  been recording since june with optical in on the jb3 and haven't had a single problem.

[Karl]

Thanks gsisak, where could I find a decent one for a good price?  That's sounds like a good option for the jb3.

Ok, thanks Brian for pointing that out--I am confusing everybody by using obscure terminology.  To clarify--what I am hearing is NOT noise with MD's ATRAC, in the means of static noise, hiss etc.  I am actually getting a very clean transfer through my iMic.  But I hear something due to the ATRAC compression scheme (artifacts?)

[dklein]

It isn't that ATRAC compression isn't audible.  I believe what David is saying is it doesn't introduce noticable noise into the recording, like the noise you're experiencing.  ATRAC compression is definitely audible, just not noisy.

yeah, that's it.  So do some recording and post some samples!  

[Karl]

Sorry that they have to be mp3's, but here are some, AT853>batt box>Sharp DR-7:

www.drumlineparkinglot.net/dci/Karl's%2003%20files/03SCVbook3.mp3