Topic: JB3 extra sample??

[fozzy]

i've been running two JB3's one via DIY optical 7pin on the sbm1 and the other via coaxmod output > ODL-276 and a few weeks ago for BHTM the hosa side had introduced 2 extra samples but once they were removed the two files compared were exactly the same(took 5 minute chunks from the same points in each file and ran em against md5).  I'm thinkin JB3 was what did this but i haven't seen this occur sense then.  the hosa JB3 is running off internals and the other one off external power.

any ideas?

[Brian Skalinder]

any ideas?

Fozzy - did the extra samples appear at the beginning of the recording?  Did you start the JB3 recording prior to feeding it the digi-signal?  Upon starting up a recording, the JB3 is a little fluky on the first ~30 samples.  Good policy to always start the JB3 a bit early so you can later trim the beginning of the recording.

[fozzy]

any ideas?

Fozzy - did the extra samples appear at the beginning of the recording?  Did you start the JB3 recording prior to feeding it the digi-signal?  Upon starting up a recording, the JB3 is a little fluky on the first ~30 samples.  Good policy to always start the JB3 a bit early so you can later trim the beginning of the recording.

this was in the middle of a 2hr set.  each recorder was rolling ~10 minutes before they came on stage. 

[Brian Skalinder]

this was in the middle of a 2hr set. each recorder was rolling ~10 minutes before they came on stage.

How did you find the two samples mid-recording - were they misplaced, i.e. outside the normal curve of the wavform?

[fozzy]

this was in the middle of a 2hr set. each recorder was rolling ~10 minutes before they came on stage.

How did you find the two samples mid-recording - were they misplaced, i.e. outside the normal curve of the wavform?

extra samples of silence while tracking i noticed the skip and upon zooming in w/ soundforge it was obvious.  When removed the curve was intact and apeared normal

[Brian Skalinder]

extra samples of silence while tracking i noticed the skip and upon zooming in w/ soundforge it was obvious. When removed the curve was intact and apeared normal

Weirdness.  Do you recall bumping the bag / cables / Hosa power supply or anything like that at the time that the artifact appears in the recording?

[fozzy]

extra samples of silence while tracking i noticed the skip and upon zooming in w/ soundforge it was obvious. When removed the curve was intact and apeared normal

Weirdness.  Do you recall bumping the bag / cables / Hosa power supply or anything like that at the time that the artifact appears in the recording?

not that i recall.  all the gear was on the FOH riser in my normal stack position. 

hosa jb3 (locked)
opti 7pin jb3 (locked)
sbm1
mp2 (vr box secured to the rear)
battery brick (4x 7.2v rc batts)

the sbm1, mp2 and batts are all taped together and look like a bomb.  The following night i had to tear into the stack cause the MP2 batteries were about to die and everything moved around but there were no issues. 

[Brian Skalinder]

Well, I'm at a complete loss.   

[fozzy]

Well, I'm at a complete loss.   

yea me too.  I'm thinking the cable must have shifted slightly or its a sign that the cable is going dead.  I can understand dropped sample or misplaced or static but the extra samples is the baffeling part.

[hexyjones]

Can you observe the extra samples in the version that is stored on JB3?

SparkE made an excellent post back in the CO2>JB3 thread about USB transfers and VIA/AMD chipsets...

Just wondering if it is a result of the transfer...

[fozzy]

Can you observe the extra samples in the version that is stored on JB3?

SparkE made an excellent post back in the CO2>JB3 thread about USB transfers and VIA/AMD chipsets...

Just wondering if it is a result of the transfer...

by the time i got around to tracking the show i had already wiped the JB3 

[hexyjones]

SparkE said:

I personally do not trust the USB interfaces on Athlon-based computers that use the VIA chipset that was common on Athlon-based machines about 4 years ago.  I've spent hundreds and hundreds of hours fighting with my Abit KT7A-RAID machine that has that chipset in it, specifically because I could not reliably get a good transfer into the machine.  The VIA southbridge chip on that design handles all USB, IDE and ISA traffic and when you put a continuous stream through any of those paths, it drops samples occasionally.  Lots of other computers using that same chipset had the same problem.  My dropped sample problems all went away when I built my new computer around a motherboard that used a 100% Intel chipset.  Until that time, I was questioning every other piece of equipment that I had.  Turns out that everything else worked fine.  It was the computer that was screwing up.

This disucussion was actually about dropped (rather than extra) samples...not added - but still of interest perhaps...

[fozzy]

fwiw this was over USB1 on a 2.4 celeron system w/ an asus board

[hexyjones]

fwiw this was over USB1 on a 2.4 celeron system w/ an asus board

You'll have to see if its an intel chipset - even though the CPU is intel - it may have VIA stuff on the board...

[SparkE!]

Yes, all my problems were actually dropped samples.  I would have to transfer a show 3 times, then compare 2 of them until they showed a difference and use the 3rd copy to figure out which of the other 2 was correct.  Then I'd correct the errant file and continue.  It was a painstaking process and a total PITA.  By the way, the missing samples usually came in groups of 30 to 100 samples.

[bhtoque]

I've had problems with the jb3 inserting samples, but they were 0db(or over) not silence. As you noted, once you zoom in and cut it out, everything is fine.

Drive cleanup got rid of the problem.

This was ua-5 optical>jb3

JAson