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Gear / Technical Help => Recording Gear => Topic started by: thesameage on July 11, 2005, 11:22:08 AM

Title: JB3 Patch off of a V3 question.
Post by: thesameage on July 11, 2005, 11:22:08 AM
I have a question that I haven't been able to answer from seaching the site. I'm going to patch off of someone's V3 rig on tuesday night. He runs the digital out from the V3 to his DAT recorder. He said that if I want to patch out, I'll need two XLR->RCA cables and then use a 1/8 adapter to go into my JB3. I'm pretty sure that I don't want to go out to the JB3 input directly, or would I? It looks like the xlr outs he's going to be giving me are analog:
http://www.gracedesign.com/products/V3/V3frame.htm

I have a Denecke AD20. Would it make sense to go XLR-XLR into the AD20, do the AD conversion there and then digital out to my JB3?

Thanks for any advice.
Title: Re: JB3 Patch off of a V3 question.
Post by: bhadella on July 11, 2005, 11:25:29 AM
Go AD20 > optical into JB3. The AD20 will sound better than the a/d in the JB3.
Title: Re: JB3 Patch off of a V3 question.
Post by: keepongoin on July 11, 2005, 11:43:14 AM
Go AD20 > optical into JB3. The AD20 will sound better than the a/d in the JB3.

except for the fact that the AD-20 adds 17 or 18 dB - so if he is running the V3 hot (like most people do), it will be clipping all over the place... unless you have some in-line attenuators.
Title: Re: JB3 Patch off of a V3 question.
Post by: thesameage on July 11, 2005, 11:49:09 AM
That is good to know. Would it still raise the volume that much if I had the AD20 totally turned down? Are attenuators something I could pick up at a place like Sam Ash (I'm in NYC and it's a block from where I work-- they seem to have a lot of this kind of stuff. Also, this isn't going to be the only time I'll patch off of this guy, so it would be worth it to figure out a long term solution.
Title: Re: JB3 Patch off of a V3 question.
Post by: keepongoin on July 11, 2005, 12:09:44 PM
the best / other solution is to get a hosa 312 (AES>optical) converter, and an AES>AES cable. 

or to get a HOSA ODL 276 to patch off of his coxial signal coming out of his DAT...


The V3 will put out line level - whatever his gain is set at... throw on a minumum of 17 dB extra - and that is with the AD-20 at zero... the recording will sound like crap... 

you should be able to some Shure (-15 db) attenuators at Sam Ash if you want to do go that route... I don't think they are all that expensive...

but the AES signal converter would be the way to get the V3 sound right out of his V3 onto your jukebox.
Title: Re: JB3 Patch off of a V3 question.
Post by: thesameage on July 11, 2005, 12:17:25 PM
Well, I think he's using the optical signal off of his V3 for his DAT. Maybe the way to go is to come straight off of the DAT digitally.

I'm going to look into the attenuators too. I think it might be a siutation where he's pretty busy and the XLR's out are the easiest thing for him to offer, so that's my best option to make his life easy.
Title: Re: JB3 Patch off of a V3 question.
Post by: keepongoin on July 11, 2005, 12:27:16 PM
optical > DAT?

that would be weird to me... as far as i know, coaxial and 7-pin inputs are what DAT recorders usually have.

it could be that he doesn't have optical output on his V3  - most of them do not if they were produced before last year... maybe serial number 400 or 450 or some where in there. 
Title: Re: JB3 Patch off of a V3 question.
Post by: thesameage on July 11, 2005, 12:53:00 PM
Sorry, I meant coaxial coming off of his V3 into his DAT.
Title: Re: JB3 Patch off of a V3 question.
Post by: Brian Skalinder on July 11, 2005, 01:07:02 PM
hosa 312 (AES>optical) converter, and an AES>AES cable.

or to get a HOSA ODL 276 to patch off of his coxial signal coming out of his DAT

Agreed, these are your best options.  Hosa ODL-276 is probably your best bet if you plan on continuing to patch with your JB3, since most taper ADCs / decks will output coax S/PDIF to patchers.  Check the JB3 FAQ in the Knowledge Base | Archive | Recording Gear forum for a touch more detail on patching with the JB3.
Title: Re: JB3 Patch off of a V3 question.
Post by: wbrisette on July 11, 2005, 02:12:05 PM
the best / other solution is to get a hosa 312 (AES>optical) converter, and an AES>AES cable. 

Will the JB3 handle the AES signal that has been converted? I know that folks that have tried their D7 and D8's out of the DEVA can't get a digital signal because they don't like the AES signal (and even in a chain with a DA-P1, downstream devices still have to contend with the AES signal).

Wayne
Title: Re: JB3 Patch off of a V3 question.
Post by: Brian Skalinder on July 11, 2005, 02:17:04 PM
Will the JB3 handle the AES signal that has been converted?

Users may set the V3 AES1 to output "consumer format data" instead of "professional format data" , per the V3 manual.  I know V3 AES1 (consumer format) > ODL-312 > JB3 works since I ran it for quite a while.  Never tried AES1 (professional format data) or AES2 (not selectable, it's always pro format data).  Not sure what precisely they mean by consumer v. pro format data, though. 
Title: Re: JB3 Patch off of a V3 question.
Post by: wbrisette on July 11, 2005, 02:28:04 PM
Not sure what precisely they mean by consumer v. pro format data, though. 

My guess would be SPDIF run at 110 ohms (the AES standard). Thus consumer "AES", whereas the Pro AES is probably the real AES signal. I have a couple of the converters that change the 110 ohms back to 75 ohms. However, I still haven't had any luck outside a DA-P1 of feeding anybody a digital signal.

Which brings up another interesting question. Obviously the V3 has two versions of the AES it can produce. What does the 722/744T offer? With more and more of these showing up in the field, it seems that the AES format may be an issue for digital feeds very soon (if devices don't support the pro version of the AES format).

Wayne
Title: Re: JB3 Patch off of a V3 question.
Post by: johnw on July 11, 2005, 03:15:45 PM
I've wondered whether the MiniMe has consumer or pro AES, but it definitely works with a 312>JB3 too.
Title: Re: JB3 Patch off of a V3 question.
Post by: F.O.Bean on July 11, 2005, 08:00:55 PM
v3>312>jb3 works w/ both pro and consumer AES signals
Title: Re: JB3 Patch off of a V3 question.
Post by: Tim on July 12, 2005, 01:56:11 AM
I've wondered whether the MiniMe has consumer or pro AES, but it definitely works with a 312>JB3 too.

the minime is pro, you cannot run anything but a pro deck off of it's aes feed
Title: Re: JB3 Patch off of a V3 question.
Post by: thesameage on July 12, 2005, 11:06:23 AM
Thanks for the info guys. Looks like my option from the taper is xlr's so I'm going to go the attenuator route. I found some 20db ones for $13 a piece at Sam Ash yesterday and I'll go get them at lunch. I also rustled up two xlr cables from around the house, so I should be set.
Title: Re: JB3 Patch off of a V3 question.
Post by: johnw on July 12, 2005, 11:56:39 AM
I've wondered whether the MiniMe has consumer or pro AES, but it definitely works with a 312>JB3 too.

the minime is pro, you cannot run anything but a pro deck off of it's aes feed

Does the step down from 110>75 in the 312 allow the JB3 to record the pro signal then? I wouldn't think the JB3 would record a pro signal that a consumer DAT deck couldn't. If you used an impedence transformer to go 110>75 from the MiniMe AES does this work for consumer DAT decks?
Title: Re: JB3 Patch off of a V3 question.
Post by: wbrisette on July 12, 2005, 12:19:48 PM
Does the step down from 110>75 in the 312 allow the JB3 to record the pro signal then? I wouldn't think the JB3 would record a pro signal that a consumer DAT deck couldn't. If you used an impedence transformer to go 110>75 from the MiniMe AES does this work for consumer DAT decks?

If the signal is a true AES signal, then the step-down only produces an AES signal at 75 ohms. No changes are made to the data format, which is why consumer decks have issues with it. It looks like Grace did a really nice thing by allowing the AES signal to simply be AES 110 ohm impedence with the SPDIF format (this could be wrong, but if consumer devices work with it, then this is what I'm guessing they are doing).

From this thread it seems that the JB3, whether by chance or design, is able to take a real AES signal that has been step-downed. D7 and D8 devices choke on AES signals and give the Copy Prohibit error when they encounter AES signals.

Wayne
Title: Re: JB3 Patch off of a V3 question.
Post by: Brian Skalinder on July 12, 2005, 12:56:01 PM
It looks like Grace did a really nice thing by allowing the AES signal to simply be AES 110 ohm impedence with the SPDIF format (this could be wrong, but if consumer devices work with it, then this is what I'm guessing they are doing).

Just confirmed this via the manual:  the V3 AES1 and coax outputs run off the same transmitter which may be configured to output consumer (i.e. S/PDIF) or professional (AES3) data formats.

If the signal is a true AES signal, then the step-down only produces an AES signal at 75 ohms. No changes are made to the data format, which is why consumer decks have issues with it.
[snip]
From this thread it seems that the JB3, whether by chance or design, is able to take a real AES signal that has been step-downed. D7 and D8 devices choke on AES signals and give the Copy Prohibit error when they encounter AES signals.

Found this snippet here (http://www.epanorama.net/documents/audio/spdif.html):

Quote
The S/PDIF interface (IEC-958) is a 'consumer' version of the AES/EBU-interface. The two formats are quite compatible with each other, differing only in the subcode information and connector.

Digging a bit deeper into that page, it looks like the reason the consumer DATs choke on the AES signal is because they interpret the presence of AES subcode info as an indication of SCMS protection, even if the data in those bits is not related to SCMS.  Seems the JB3 doesn't care about SCMS and so doesn't care if data exists in the subcode bits.