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Gear / Technical Help => Recording Gear => Topic started by: MattD on June 25, 2003, 01:18:06 PM
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Since I've never seen one of these, I'm only going on speculation here. Is the optical input a miniplug or TOSlink?
If it's a TOSlink, wouldn't it be relatively easy to replace that receiver with a coaxial input? I realize there are slightly different voltage requirements of the signal, but some chips are more forgiving than others when it comes to that.
If it's a miniplug, I have a 1/8" SPDIF (and a 1/8" to coax converter) which might also be swapped without much difficulty.
If anyone has opened their JB3, or is willing to to take some good pics of the digital input, I'd be interested in at least looking at the innards while trying to figure out if it could be modded.
That's my random techie rambling for today.
-Matt
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find a way to MOD it so it can accept 24 bit and then we would be talking......
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Haha, I wish - that'd be far more useful to me as well. However, that would require a complete rebuild of the digital stage as well as a software rebuild/hack.
*Praying for SD to strip all the features from its HD series and just release a recorder at some point*
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Matt, it's a miniplug as the optical in also acts as an analog in.
Here are some pictures of the guts. Hope you the best of luck, glad to see some JB3 interest!
http://tinyurl.com/f8v8
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go Matt go- go Matt go! :yahoo:
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Well, it LOOKS like the optical piece could be replaced by an RCA jack if you drilled out the case a little bit more.
What I need to find is the specs on the voltages and see if the optical outputs the same voltages to the pins as the SPDIF would. If not, then I'd have to build a buffer circuit. While that would work, it'd be too big to fit inside, which would defeat the purpose.
If I find that the voltages are the same, or that the circuit can fit in there somewhere, I'll try to find some way to test it out, or talk to someone who can.
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of course, if you hacked it to accept coax, you'd give up your analog input-unless you can move that to one of the line out jacks or something like that.
possibilities...
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of course, if you hacked it to accept coax, you'd give up your analog input-unless you can move that to one of the line out jacks or something like that.
possibilities...
small price to pay...imo...to get out of the optical realm.
most of us are not using the analog in at all???
am i right here?
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optical all the way 8)
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I used the analog in when I was stealthing; mp-2>1/8">jb3 analog in
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It would be nice if it was just a toslink and not a mini combo analog. those mini adapters break so easily it is sickning!
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interesting that this topic comes up, the other day there was a post on /. about hacking it for more memory... im considering working on mine for the coax mod
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Okay ... with a voltmeter, find out the voltage the optical receiver puts out while a signal is being passed. Take a SPDIF and pass signal through that and measure the output voltage as well. Use the SPECIFIC digital gear you'd be using in the field. If they are similar volatages, then you might be able to do a straight swap, keeping your signal and ground the same, and just not connecting the analog to anything.
If they do not output the same voltage, you would need to construct a buffer circuit similar to those in an external box, I'd assume. If you're good with soldering, it shouldn't hurt to try the swap anyway b/c you can always solder the original piece back on if it doesn't work with the coax.
*disclaimer* this is your gear - if you slip with soldering or feed a nonstandard voltage into the unit, damage can occur. Not to discourage, but just to let you know that bad can happen.
Let me know how it goes and if you need any help. If you can post a close-up of the jack, I might be able to tell you which is signal and ground if you can't. You can probably get an RCA jack at radioschwag.
-Matt
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I might try to hack mine after I pick up my 722...