Topic: JB3 Patch off of a V3 question.

[thesameage]

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.

[johnw]

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?

[wbrisette]

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

[Brian Skalinder]

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:

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.