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Post by jacobamerritt on Dec 8, 2023 0:08:13 GMT -6
So I am setting up for a session and it seems ALL my condenser mics are getting phantom power even when the button is not engaged on the preamps?? This is happening on every condenser mic and both preamps I’ve tried (Iron Age and Alice Console). I have everything going through a patchbay but how could that make this happen? Am am a missing something obvious??
It’s making me feel crazy and stressed.
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Post by enlav on Dec 8, 2023 0:36:36 GMT -6
If I weren't in bed getting ready for an early morning, I'd offer to walk through it with you.
Panic is understandable, but before doing anything, if your motu has meters for your inputs, check there to make sure you're seeing signal going in. Or create a brand new session to verify you're seeing signal on all those condensers.
These are just sanity checks.
If there is signal going through, and the inputs are all assigned correctly on your DAW, I'd start carefully monitoring the channels to see if it's noise or something.
Best of luck.
Edit.. also, I'm not an expert here.. is it possible that phantom, if engaged on one channel that was missed, could be shorting at the snake/patchbay and powering other mics?
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Post by jacobamerritt on Dec 8, 2023 0:54:04 GMT -6
If there is signal going through, and the inputs are all assigned correctly on your DAW, I'd start carefully monitoring the channels to see if it's noise or something. Best of luck. Edit.. also, I'm not an expert here.. is it possible that phantom, if engaged on one channel that was missed, could be shorting at the snake/patchbay and powering other mics? Ok... So if I turn off the phantom from everything no phantom gets passed! Then if I turn the Alice console power back ON, it works even on the mic that is only going through the Iron Age while phantom is turned OFF on that channel of the Iron Age. So maybe the patchbay configuration is sending phantom to everything via the Alice?? |
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Post by the other mark williams on Dec 8, 2023 0:58:06 GMT -6
If there is signal going through, and the inputs are all assigned correctly on your DAW, I'd start carefully monitoring the channels to see if it's noise or something. Best of luck. Edit.. also, I'm not an expert here.. is it possible that phantom, if engaged on one channel that was missed, could be shorting at the snake/patchbay and powering other mics? Ok... So if I turn off the phantom from everything no phantom gets passed! Then if I turn the Alice console power back ON, it works even on the mic that is only going through the Iron Age while phantom is turned OFF on that channel of the Iron Age. So maybe the patchbay configuration is sending phantom to everything via the Alice?? Are your mics plugged directly into their respective preamps, or are they plugged into the patchbay? Some weird things can happen if phantom is being sent through a patchbay… |
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Post by Blackdawg on Dec 8, 2023 1:07:24 GMT -6
How are you patch bays wired?
For mic's you want isolated grounds
Then I'd either do half normalled or even non normalled.
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Post by jacobamerritt on Dec 8, 2023 3:33:51 GMT -6
How are you patch bays wired? For mic's you want isolated grounds Then I'd either do half normalled or even non normalled. Im pretty sure half normalled. I need to check tomorrow. Thankfully I only have a couple ribbons up for the session, but just overnighted some Se Dynamites just in case. |
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Post by enlav on Dec 8, 2023 7:58:25 GMT -6
Yeah, depending on how your patchbay is wired, that would presumably be the culprit.
The most I would do in this scenario is just hook up everything up cold before engaging phantom power. Only after ensuring I have no gear that could be sensitive to 48v on the patchbay.
Further measures of precaution would come based on how much or how little you trust the wiring and/or solder job in the patchbay or if there are half/fully normaled patches that have the Alice's mic inputs connected to other preamp or sensitive gear (which usually won't be the case).
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Post by svart on Dec 8, 2023 8:04:36 GMT -6
Doubt it would be passing phantom to all channels via the patchbay. If it passes phantom, then it would also probably pass audio and you'd have a lot of crosstalk.
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Post by svart on Dec 8, 2023 8:07:36 GMT -6
It could be that there's a common ground for all the channels through the patchbay, and that one channel is wired wrong that would "power" everything connected to ground. You could use a DMM from the mic shells to an outlet ground and see if it's floating to 48V.
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Post by enlav on Dec 8, 2023 8:22:11 GMT -6
Rereading the thread now that I'm not on a phone --- if I'm jumping to conclusions, I apologize, but is the Alice providing phantom without it engaged? And does the Alice provide phantom to all channels via one global switch, or is it channel by channel?
It could be that there's a common ground for all the channels through the patchbay, and that one channel is wired wrong that would "power" everything connected to ground. You could use a DMM from the mic shells to an outlet ground and see if it's floating to 48V. In layman's terms, only one channel needs a short to the common ground for this to happen - is that correct?
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ericn
Temp
Balance Engineer
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Post by ericn on Dec 8, 2023 8:33:14 GMT -6
Take a mic , bypass the bay if it isn’t seeing phantom without it engaged it’s the bay wiring . What kind of bay is it.
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Post by jeremygillespie on Dec 8, 2023 10:06:35 GMT -6
Plug everything in except the mics. Then patch a cable into the bay and use a meter to check the other end for phantom. Turn console on and off and repeat.
Some consoles just have a global switch to turn it on/off. It won’t hurt anything to be on even with mics that don’t need it, but don’t plug or unplug patch cables while it’s on.
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Post by jacobamerritt on Dec 8, 2023 11:30:56 GMT -6
This is all helpful, I think maybe it’s that the first 8 channels of my patchbay inputs are wired to the Alice, but can be bypassed by patching to other preamps on those channels.
It’s half normalled.
Today I’ll see if power is actually going to the Alice channels when the Alice has no Phantom engaged but other preamps do!
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Post by Deleted on Dec 8, 2023 11:55:04 GMT -6
This is all helpful, I think maybe it’s that the first 8 channels of my patchbay inputs are wired to the Alice, but can be bypassed by patching to other preamps on those channels. It’s half normalled. Today I’ll see if power is actually going to the Alice channels when the Alice has no Phantom engaged but other preamps do! Alice 828 enables phantom power for every input and pre when you hit the phantom button. Just don’t use ribbon mics. It’s an old broadcast design from after ribbons were popular. If you want to anyway, have your ribbon mics on the mixer pres and your condensers on external pres with phantom or use an external phantom power supply if you want to use the Alice pres. No big deal. |
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Post by jacobamerritt on Dec 8, 2023 13:19:20 GMT -6
This is all helpful, I think maybe it’s that the first 8 channels of my patchbay inputs are wired to the Alice, but can be bypassed by patching to other preamps on those channels. It’s half normalled. Today I’ll see if power is actually going to the Alice channels when the Alice has no Phantom engaged but other preamps do! Alice 828 enables phantom power for every input and pre when you hit the phantom button. Just don’t use ribbon mics. It’s an old broadcast design from after ribbons were popular. If you want to anyway, have your ribbon mics on the mixer pres and your condensers on external pres with phantom or use an external phantom power supply if you want to use the Alice pres. No big deal. Yes I know. I had it custom built new by Alice/Ted Fletcher. And there's only one button on the whole console for phantom, so it would be hard to miss  . I do the opposite, and never use my ribbons on the Alice console channels. It's most likely a patchbay setup situation. Today Im figuring out if the Iron Age phantom is migrating to the Alice channels. Got some sE Dynamites and FETheads for my ribbons as a fail safe option regardless. |
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Post by notneeson on Dec 8, 2023 20:36:01 GMT -6
Alice 828 enables phantom power for every input and pre when you hit the phantom button. Just don’t use ribbon mics. It’s an old broadcast design from after ribbons were popular. If you want to anyway, have your ribbon mics on the mixer pres and your condensers on external pres with phantom or use an external phantom power supply if you want to use the Alice pres. No big deal. Yes I know. I had it custom built new by Alice/Ted Fletcher. And there's only one button on the whole console for phantom, so it would be hard to miss . I do the opposite, and never use my ribbons on the Alice console channels. It's most likely a patchbay setup situation. Today Im figuring out if the Iron Age phantom is migrating to the Alice channels. Got some sE Dynamites and FETheads for my ribbons as a fail safe option regardless. Active ribbons are so nice for this reason. |
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Post by Pueblo Audio on Dec 8, 2023 21:39:21 GMT -6
Yes I know. I had it custom built new by Alice/Ted Fletcher. And there's only one button on the whole console for phantom, so it would be hard to miss . I do the opposite, and never use my ribbons on the Alice console channels. It's most likely a patchbay setup situation. Today Im figuring out if the Iron Age phantom is migrating to the Alice channels. Got some sE Dynamites and FETheads for my ribbons as a fail safe option regardless. Active ribbons are so nice for this reason. Pardon my exception, but this is not nice from sonic achievement goal. When you want to “fly” when touring on your bike, one can’t catch the spirit when training wheels are still attached and dragging you down. Trading band-aids for protection from easily controlled exposures is a step backwards. This is engineering 101. Just Be aware. It costs nothing but rewards with fidelity. |
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Post by notneeson on Dec 8, 2023 22:01:00 GMT -6
Active ribbons are so nice for this reason. Pardon my exception, but this is not nice from sonic achievement goal. When you want to “fly” when touring on your bike, one can’t catch the spirit when training wheels are still attached and dragging you down. Trading band-aids for protection from easily controlled exposures is a step backwards. This is engineering 101. Just Be aware. It costs nothing but rewards with fidelity. I like the active Royers, they’re great mics. The 122v in particular is super cool. The fact that 48v is a non issue is a bonus. That said, have never had an issue with ribbons and 48v anyway. I guess I’m just a sonic underachiever. 😕 |
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Post by Blackdawg on Dec 9, 2023 1:00:33 GMT -6
It could be that there's a common ground for all the channels through the patchbay, and that one channel is wired wrong that would "power" everything connected to ground. You could use a DMM from the mic shells to an outlet ground and see if it's floating to 48V. this is why i asked about the grounding. Good patch bays let you select this. And isloated grounds would be the way to go. |
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Post by matt@IAA on Dec 9, 2023 15:43:39 GMT -6
If you run into an issue please give me a shout.
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Post by jacobamerritt on Dec 9, 2023 16:46:28 GMT -6
If you run into an issue please give me a shout. It’s definitely not an issue with the Iron Age QPP, just the way we have the studio patchbay configured. |
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