Taperssection.com
Gear / Technical Help => Ask The Tapers => Topic started by: Brian Skalinder on December 12, 2003, 01:03:15 PM
-
Alright, so I'm gearing up to do some stability and bit-accuracy testing with my new Hosa ODL-312 digital format converter (AES/EBU coax <-> S/PDIF optical). After a brief 1 hour test last night and this morning, no visible or audible glitches. So far so good, though I obviously have a long way to go.
I'm running mics > V3 (16/44) and the following simultaneous digital outputs:
[1] Radio Shack coax > RCA barrel > Hosa coax > EgoSys Waveterminal 2496 > CEP2.0
[2] AES/EBU > Hosa ODL-312 > Hosa optical toslink w. toslink/mini adapter > JB3
I transferred the JB3 WAV over an Adaptec Fireconnect 4300 using Notmad Explorer. V3 is powered by a 6v SLA and the ODL-312 is powered by a 9.6v RC battery. FWIW, I wired up the AES/EBU cable per the V3 pinouts:
Pin 1: shield
Pin 2: (+) hot
Pin 3: (-) ground
In the process of trying to trim the WAVs to the same starting/finishing sample so I could do a WAV comparison, I noticed something odd: one of the two sources is flipped L/R relative to the other: source [1]'s left channel = source [2]'s right channel (or vice versa). WTF!!
I haven't checked yet which source is flipped as I had to get into work this morning. But regardless of which is flipped, I'm at a loss here. How can the L/R channels be swapped during a digital transfer of data?!?!? Maybe the Hosa ODL-312 flips channels in the course of converting AES/EBU > optical? But that seems awfully odd to me. Anyone?!?
-
unless the inputs are backwards. that could be. i had an old stereo that was backwards. i'd plug somthing in the left channel, and it played out of the right speaker, kinda weird. thats the only explanation i can give ya, is that, kinda weird. +t for your troubles..
matt
-
unless the inputs are backwards. that could be. i had an old stereo that was backwards. i'd plug somthing in the left channel, and it played out of the right speaker, kinda weird. thats the only explanation i can give ya, is that, kinda weird. +t for your troubles..
matt
If the inputs are backwards, it would be consistent for both digital sources, since the inputs go to the V3 and both digital sources are derived from the V3 simultaneously.
The only inputs that could be backwards and have this effect are the digital outputs. And the digital outputs each have a single cable, so...nothing to get backwards. Which is why I'm confused!
-
oh... well i thought maybe the input to like the jb3 for instance when it decode the digital signal, it decodes them backwards.. i don't know.. it is pretty confusing.
-
oh... well i thought maybe the input to like the jb3 for instance when it decode the digital signal, it decodes them backwards.. i don't know.. it is pretty confusing.
Yeah, I don't get it. I figure I must've screwed something up in my haste to get some tests going. I'll have to check tonight when I have more time.
-
I remember running into this before - it's likely in the digital realm. I'm sure a quick little test will tell you which device it is. You can also run headphones into the monitor of the v3, JB3 and PC to see what's going on. Don't be surprised if it monitors correctly and plays back reversed!
I think when I experienced this, it was with a Nightingale soundcard and it wasn't consistent. Even weirder.
-
I remember running into this before - it's likely in the digital realm. I'm sure a quick little test will tell you which device it is. You can also run headphones into the monitor of the v3, JB3 and PC to see what's going on. Don't be surprised if it monitors correctly and plays back reversed!
I think when I experienced this, it was with a Nightingale soundcard and it wasn't consistent. Even weirder.
No doubt I'll figure out what's happening fairly quickly when I get home. Only question will be *why* it's happening. This oughta be interesting!
-
mayeb it's the v3 ;D, j/p
-
Alright, after some additional testing, everything seems fine. WTF. I must've screwed something up. Thread closed.
-
I was wondering how this would play out. Good luck figgerin' it out!
-
did ya swap em in wavelab??? ???
brian, cant wait to hear the converter results......can you see if bits are being dropped in wavelab or anything???
-
Hey Brian,
I just ran into this same problem. Channels on my JB3 have reversed. First time was last fri the 11 of Feb at the STS9 show at the HOB in CHicago. And the same thing happened tonight while recording some drums in my basement. I've never had this problem before, been running the JB3 for about 9 months. Yet the first time it happened was the first time I used a AD 500E with my rig. I just used it tonight for the second time and it happened again. Maybe the AD500E and the JB3 do not mix? Before I was running a AD20 behind it with no problems. BTW both times it happend while I was recording, pushed pause, and then resumed. Before the pause, levels were correct, after the pause, swapped. Any advise would be helpful.
Thanx for the great site
-Charlie Barlow
-
a stumper!
marc
-
my V3 has always been like this. i've just ignored it and dealt with it by pugging my right microphone into channel 1 and my left microphone into channel 2. kind of weird but i think the circuitry in the AD section could be switched at some point in some V3 models.
-
Ok - other users have reported that the JB3 will swap channels if you use the pause button.
I had this happen last week...I accidentally hit pause, and then unpaused...that set, the channels are reversed. All the other sets from that evening are fine...
Ya know...this is something that we really need to pay attention to - just imagine how many recordings out there are completely horked because the channels are swapped...
I think this needs to be raised to "hair on fire" level for the JB3 users...seems like a huge flaw in this recorder...not that big of a deal if you keep it in mind...who uses pause anyway?!!!
From now on jiggle your car keys in front of the left mic before each set...make sure that jiggle is on the left when you get home...
-
FYI, as reported in my full ODL-312 testing thread, I nailed down this problem to my EgoSys Waveterminal 2496, NOT the JB3.
Ok - other users have reported that the JB3 will swap channels if you use the pause button.
I've encountered no such problems. Anecdotal evidence, no different than the CO2. :P
I think this needs to be raised to "hair on fire" level for the JB3 users...seems like a huge flaw in this recorder...not that big of a deal if you keep it in mind...who uses pause anyway?!!!
Eh, L/R swap isn't that big a deal, and it's easy to confirm and/or work around (per your key jingle comment). At least the bits are still there, unlike the CO2.
-
So I guess do not use the pause/record function. And for me I always used that, I guess a hold over from my dat days; pause/record is a much faster way to start recording, none of that waiting for the jb3 to load a file and start. Oh well, I guess worse things could happen. Thanx again guys for the input.
-CHarlie Barlow
-
brian,
i have the same problem with my wavterminal 2496. go figure!
-
I/O conflict being caused by CEP and your CPU. It's a known problem.
It also exists with audio cards independently from software, and vice versa.
-
interesting little thing... i am playing with my new mics ;D and when i am monitoring the sound in the room, the level meters on the jb3 are switched from left to right, but when i press record, the levels correspond to the correct channel (red / right).... i guess this is only true if i am reading the meters correctly. the first column would be left and second right.
thinking about this more makes me wonder if i am even orientating myself correctly. i assume that if you are facing the music, the right side is the right channel to be recorded by the right mic. eh... too tired to do anymore tonight - just happy to play with the new toys... :D
-
i found out that it was happening to me at the spdif input of the ap2496 - the card would switch the channels during the transfer. i remember reading about this on the avs forums years ago, when i first bought the card. but i forgot about it when s started transferring DATs. there is reg setting to swap channels on the card (rather than having to do it via DSP), but i forget what it is. now i have to retransfer everything from the past several years (ACK!)...
-
I can attest to the fact that the WT2496 does indeed swap channels via the coax digi-in. It monitors normally, but when I play back the .wav off the HDD the channels are indeed swapped. FWIW, I'm running win2K and the card does this everytime without fail.
-
i found out that it was happening to me at the spdif input of the ap2496 - the card would switch the channels during the transfer. i remember reading about this on the avs forums years ago, when i first bought the card. but i forgot about it when s started transferring DATs. there is reg setting to swap channels on the card (rather than having to do it via DSP), but i forget what it is. now i have to retransfer everything from the past several years (ACK!)...
just do channel swaps in wavelab or something :) that will save you many months :)
-
i found out that it was happening to me at the spdif input of the ap2496 - the card would switch the channels during the transfer. i remember reading about this on the avs forums years ago, when i first bought the card. but i forgot about it when s started transferring DATs. there is reg setting to swap channels on the card (rather than having to do it via DSP), but i forget what it is. now i have to retransfer everything from the past several years (ACK!)...
just do channel swaps in wavelab or something :) that will save you many months :)
yeah, but that puts a dsp step in there that i do not want...
-
could you REALLY hear the DAW doing a chennel swap ??? i know i prolly couldnt
i trust wavelab/soundforge doing any DSP work, thats whatthey were made to do
i dunno, i should try it myself and see, but i doubt HIGHLY you could hear artifacts or something strange in a channel swap in wavelab, YMMV
-
could you REALLY hear the DAW doing a chennel swap ??? i know i prolly couldnt
i trust wavelab/soundforge doing any DSP work, thats whatthey were made to do
i dunno, i should try it myself and see, but i doubt HIGHLY you could hear artifacts or something strange in a channel swap in wavelab, YMMV
it is more of a theoretical thing with me. who knows what i hear, or think i hear..? and who knows what i will hear on the next system i build..?
i am certainly not trying to insinuate that i have golden ears; i simply want to do my transfers right.
-
could you REALLY hear the DAW doing a chennel swap ??? i know i prolly couldnt
i trust wavelab/soundforge doing any DSP work, thats whatthey were made to do
i dunno, i should try it myself and see, but i doubt HIGHLY you could hear artifacts or something strange in a channel swap in wavelab, YMMV
it is more of a theoretical thing with me. who knows what i hear, or think i hear..? and who knows what i will hear on the next system i build..?
i am certainly not trying to insinuate that i have golden ears; i simply want to do my transfers right.
thats fair, i feel ya there, i used to be the saem way, but after lots of listening sessions on my current playback system, i cant hear stuff like that, especially when i do it in wavelab, it seems more rock solid IMO when it comes to DSP work
-
You know, I don't have Wavelab, but it seems to me that there should be some way for you to test whether the channel swapped version had bit literal copies of the original tracks, just with the channels swapped. I can't imagine that your DSP routine that swaps channels would actually do anything but take the left channel samples and put them into the right channel and vice versa. Do you have a short track that you could post both original and channel swapped versions? I'd be happy to take a look to see if there are any differences except for swapping the channels.
I just hate to see tapers spend their time re-doing things if it can be done with less effort in less time another way. We have too much to do as it is. Heck, I probably have 3 dozen shows that are still sitting on the original tapes (and I'm not a heavy taper). I'd hate to think that I had to completely re-do every other show I've ever recorded before I could start working on the shows I've never even transferred, especially if all that was wrong was that the channels were swapped.