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Author
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Topic: AES/EBU to spdif cable question
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stein r
EX5Tech Veteran
Member # 480
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posted August 13, 2003 02:56 PM
    
I made one of these AES/EBU to spdif cables and it works great, going into my friends MOTU 2408 interface. I would not recommend it to anyone with little experience soldering cables, though. That's a very tight squeeze, getting those components inside the XLR wihout touching each other.Better to make a small breakout box with the components, then you can use regular XLR mic cables and an RCA to RCA cable to make connections.
By the way, is there some substance that can be squirted in between the wires inside the XLR plug, to isolate them better from one another? Superglue? Rubber cement? Also, - what would happen if someone took my special cable and tried to connect, say a microphone to a gadget with RCA in? (I am reposting this as a new thread, as I'm curious about my questions)
Posts: 187 | From: Fredrikstad, Norway | Registered: Nov 2001 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted August 13, 2003 04:13 PM
I also would like the hear the answer. I just got the digital out board, so I plan on making one of these shortly. My electroncs experience is about zero (does metal shop count?), so I'm beginning to wonder if I could even make a decent one myself. I will try. If I fail, is there someone in the states able to make these well and quickly, who would be willing to make some and sell them to those of us who aren't electronics-savvy? ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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Greg
EX5Tech Veteran
Member # 1612
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posted August 13, 2003 10:05 PM
As far as what to use to insulate and firm up cableing solder connections, you can use RTV purchased from a hardwre store. This will assist as a strain relief too.Don't know much about SPDIF yet, still have a lot to learn, but if someone can give me a drawing and some Radio Shack part numbers, I can make a few cables and ship via postal. I was an electronics tech and engineer for a while. Now doing data center management and EX learning. Let me know if I can help. ____________________ Greg http://www.lauriastudios.com EX FOREVER!
Posts: 136 | From: Plainfield, IL, USA | Registered: Nov 2002 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted August 14, 2003 04:54 PM
Click here to get to a relevant thread.Click here for a link to a webpage that provides the instruction to making your own "AES to spdif adapting cable" ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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Jim
EX5Tech Team
Member # 494
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posted August 16, 2003 05:26 AM
Room Temperature Vulcanising compound.Sets rubbery and insulates, at room temperature. ____________________ Jim
Microsoft browsers are a bit better but still rubbish and leaky, don't tolerate them. Get Firefox now! Run, don't walk! http://www.mozilla.org/products/firefox/
Posts: 2546 | From: Stourbridge, West Midlands UK | Registered: Dec 2001 | IP: Logged
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Greg
EX5Tech Veteran
Member # 1612
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posted August 18, 2003 07:11 AM
quote:
Back to the sealant: Is this the same RTV sealant you buy in a car part store for making gaskets?[ August 18, 2003: Message edited by: stein r ][/QB]
Same thing, just different properties. The stuff used for gaskets can withstand much higher temps and presures without breaking down. It's also more expensive. We could always get the 91 ohm resisters from Digikey http://www.digikey.com/ in bulk if there was enough interest. ____________________ Greg http://www.lauriastudios.com EX FOREVER!
Posts: 136 | From: Plainfield, IL, USA | Registered: Nov 2002 | IP: Logged
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Jim
EX5Tech Team
Member # 494
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posted August 18, 2003 04:10 PM
Erm, chaps, a 92 ohm resistor is a standard range part readily available.For the miniscule error it theoretically introduces, it does not matter one iota and you can at least get them. Cable tolerances will have more effect than than this small difference. I'm using a 92 ohm resistor and it works just fine. HTH ____________________ Jim
Microsoft browsers are a bit better but still rubbish and leaky, don't tolerate them. Get Firefox now! Run, don't walk! http://www.mozilla.org/products/firefox/
Posts: 2546 | From: Stourbridge, West Midlands UK | Registered: Dec 2001 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted August 18, 2003 04:26 PM
quote:
I am an electronic tech and would be happy to make cables, free of course.
Personally, I would want to at least pay for the parts and shipping. If you want to donate your time, talent and labor for free, that's very generous, but I would still want to give you something for your trouble. If you want to offer it completely free-of-charge and cover all the costs, that's overly generous IMO, but your prerogative. ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted August 19, 2003 06:30 PM
Yes, the female XLR is needed to plug into the EX digital out. That's an interesting picture, because I was assuming more of a cable with the fem XLR on one end and a male RCA on the other, because of the 70ohm cable requirements. I pictured a 70ohm, shielded coax cable of varying length, a female XLR soldered to one end (which would have the components discretely soldered inside), and a male RCA on the other. But something like what that picture is showing would work, but it would need to end in a female RCA, since the spdif cables we would then plug into it have male RCA's on both ends. Then we would use whatever lenght spdif cable we needed. To be honest, the cable idea sounds better to me, since it's flexible, and cables can be taped to the ground. The adapter model is a rigid piece of metal plugged into my EX Dig board, protruding out a couple more inches...just one more thing to worry about me or someone else clipping as they walk by and breaking something. Either way though, I'd be glad to beta-test it for you!
Here's a link
[ August 19, 2003: Message edited by: E ] ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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stein r
EX5Tech Veteran
Member # 480
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posted August 19, 2003 06:48 PM
For my cable, I bought an expensive 6' RCA to RCA cable with gold connectors, and cut off one of the ends. Then I soldered a female XLR plug to that end, with the 91 and 330 ohm resistors inside the plug. I used my multitester to double check the ohmage, and it matched the values on the schematic.I used the "AES/EBU to S/PDIF signal level converter" schematic that's halfway down this page:http://www.epanorama.net/documents/audio/spdif.html The adapter looks like a good idea, though. You don't have to have it sticking out of the keyboard, just use a female to male XLR cable, then put the adapter at the other end. Leaves you free to experiment with different lengths and qualities of either XLR/XLR or RCA/RCA cable. Besides, you wouldn't be likely to use the digital out at a live gig, anyway. Just leave the adapter home (unless you are running through a digital mixer ? ?) [ August 19, 2003: Message edited by: stein r ]
Posts: 187 | From: Fredrikstad, Norway | Registered: Nov 2001 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted August 20, 2003 11:32 AM
You can get by with a less than 75ohm cable, but theoretically you could run into problems if you don't. You definately want shielded cable. Wouldn't it be just as easy to get a mic cable, cut off the male end and solder a gold-plated rca jack, and modify the female xlr end with the components? If you want to use canabalize rca cables, email me, give me your address, and I'll send you some hi-def rca cables you can experiment with. If you make an adapter, I think it should terminate in a female RCA. Because, every spdif cable I've seen has male rca jacks on both ends. If you make a cable, it should treminate with a male rca. [ August 20, 2003: Message edited by: E ] ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted September 04, 2003 02:23 PM
I got it yesterday, everything looks fine, haven't had a chance to use it yet, may be a little while before I do...mom in town for two weeks...immediately followin, wife and I take a week vacation, then fiscal year end at work....AAHHHHHH!Perhaps someone else could bench test it sooner? ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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E
EX5Tech Veteran
Member # 5
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posted April 28, 2004 12:32 PM
UPDATE: I finally installed the Digital Output upgrade. I used the cable "Ismellelephant" made to connect it to the spdif input on my OASYS card, and it worked like a charm. I was able to effect the EX voice with OASYS effects. Even without OASYS effects, the voice sounded better through the OASYS digitally than it did on the EX mains (yes, using the same monitors!) Granted, I didn't run anything like a oscilloscope to compare and analyze things, but it sounded good to my ear. FYI, the cable Ismellelephant used was a single strand from a Hi-Def Component Video cable my work sells, which uses 75ohm coaxial RG59. The EX manual states "Use a cable with impedance characteristics, 110 ohm" (p. 287). According to the manual, is this 75 ohm cable within specs? ____________________ E!
Posts: 1766 | From: California, USA | Registered: Jun 2001 | IP: Logged
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Jim
EX5Tech Team
Member # 494
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posted April 28, 2004 07:50 PM
Hi E!The manual assumes that you will run a cable from the AES/EBU output to a similar input on another AES/EBU device which also expects 110 ohm impedance, hence the advisory on the cable. With the converter circuit, the EX5 output sees a higher impedance than 110 ohm which is OK since although theoretically mismatched at about 400 ohm it won't load the output circuit and the S/P-DIF standard is 75 ohms which the cable will match nicely. The 92 ohm resistor in parallel with the 330 ohm and the EX5 output impedance in series is close enough to 75 ohm anyway so no problem there. In short, no problem - certainly mine works a treat! Jim ____________________ Jim
Microsoft browsers are a bit better but still rubbish and leaky, don't tolerate them. Get Firefox now! Run, don't walk! http://www.mozilla.org/products/firefox/
Posts: 2546 | From: Stourbridge, West Midlands UK | Registered: Dec 2001 | IP: Logged
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