Cacophony Forums
Unofficial Mackie User Forums => DL1608/DL806/DL32R/ProDX Mixers => Topic started by: Fluddman on May 02, 2015, 03:12:09 AM
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Anybody else have this happen.
When phantom power is on channel 8 makes noise even without any thing connected. Its quite a strong signal, and makes that channel unusable.
It works fine with phantom power off - so it sounds like somethings up with the preamp.
Any suggestions on how to fix it.
Cheers
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Sounds like a problem with your mixer. I've never experienced it. I bought a small mixer with phantom power to deal with that need. I hate global phantom power. (But have used it from time to time. Just trying to move away from it.) Not aware of any easy fixes. Could be a flakey connection on that input. If the mixer is out of warranty, you might either look at it or have someone look at it. the connection issue should be an easy fix. Anything else is unlikely to be an easy fix. (My take anyway.)
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Does this happen regardless of the channel that has the phantom power supplied?
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Sounds like a problem with your mixer. I've never experienced it. I bought a small mixer with phantom power to deal with that need. I hate global phantom power. (But have used it from time to time. Just trying to move away from it.) Not aware of any easy fixes. Could be a flakey connection on that input. If the mixer is out of warranty, you might either look at it or have someone look at it. the connection issue should be an easy fix. Anything else is unlikely to be an easy fix. (My take anyway.)
Yeah I hate global phantom power as well!
My DL is out of warranty by now so I'll probably look at it myself.
CHeers
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Does this happen regardless of the channel that has the phantom power supplied?
Not quite following your question.
Phantom power is global on the DL - so when it's on, it's on for all channels.
Only channel 8 has the noise problem (at the moment).
Cheers
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Take lots of photos while taking it apart. There are already some on this website somewhere. And make sure you have access to a backup mixer just in case things don't go well.
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Phantom power is global on the DL - so when it's on, it's on for all channels.
Not on my DL32R. It's set through Master Fader for each channel individually. So, when you say DL, can you be more specific?
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That is a serious reason to consider the DL32r over the DL1608 if you don't need all that many channels. I'm betting that can't be done with the 1608 without some kind of redesign. I would have preferred that phantom power only be available on 1/4 to 1/2 of the channels.
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Phantom power is global on the DL - so when it's on, it's on for all channels.
Not on my DL32R. It's set through Master Fader for each channel individually. So, when you say DL, can you be more specific?
Sorry Michael, mine is a 1608. Wish i had the 32R though.
CHeers
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Most likely the DC blocking cap leaking which means replacement. Check the 48V on pin 2 and 3 just in case, pin 1 is ground. Unlikely that the resistors failed but just in case. I don't know if you are a DIY guy so all this may be for someone else. I don't know of anywhere that the analog section of the DL has been photoed so if you take it apart snap some pics please.
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Anybody else have this happen.
When phantom power is on channel 8 makes noise even without any thing connected. Its quite a strong signal, and makes that channel unusable.
It works fine with phantom power off - so it sounds like somethings up with the preamp.
Any suggestions on how to fix it.
Cheers
Just been checking the noise issue you’re experiencing with phantom power on channel 8. No noise for me, but this is the first time that I’ve seen the channel meters spike (all of them) 1/4 of the way up the scales when I turn the phantom power on or off. This occurs with all channels muted or un-muted inc’ Main and all volume controls at the bottom or turned up .
Didn’t notice this with MF 3.0.2, but seeing it with 3.1. I’m putting it down to a power spike through the circuit when the phantom switch is turned on and a drain of power when turned off. This reflects in the channel meters. No pops or click sound through the headphone output or the main outs. Maybe it was always there but really just noticed it. Doesn’t seem to affect the overall workings of the mixer at all. Weird.
It's a DL1608.
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Most likely the DC blocking cap leaking which means replacement. Check the 48V on pin 2 and 3 just in case, pin 1 is ground. Unlikely that the resistors failed but just in case. I don't know if you are a DIY guy so all this may be for someone else. I don't know of anywhere that the analog section of the DL has been photoed so if you take it apart snap some pics please.
Thanks WK. I'll definitely being having a go at it my self and will post pics. Its working perfectly except for the phantom power issue so I am going to wait for the next free weekend.
Cheers
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Anybody else have this happen.
When phantom power is on channel 8 makes noise even without any thing connected. Its quite a strong signal, and makes that channel unusable.
It works fine with phantom power off - so it sounds like somethings up with the preamp.
Any suggestions on how to fix it.
Cheers
Just been checking the noise issue you’re experiencing with phantom power on channel 8. No noise for me, but this is the first time that I’ve seen the channel meters spike (all of them) 1/4 of the way up the scales when I turn the phantom power on or off. This occurs with all channels muted or un-muted inc’ Main and all volume controls at the bottom or turned up .
Didn’t notice this with MF 3.0.2, but seeing it with 3.1. I’m putting it down to a power spike through the circuit when the phantom switch is turned on and a drain of power when turned off. This reflects in the channel meters. No pops or click sound through the headphone output or the main outs. Maybe it was always there but really just noticed it. Doesn’t seem to affect the overall workings of the mixer at all. Weird.
It's a DL1608.
I think it would be normal to see the spike when you power phantom on or off (as you can hear if you are not muted). My channel 8 is almost a full scale signal!
Cheers
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Hey, Fluddman
Thanks for your reply. Yeah, I agree that the spikes I am seeing are normal. Makes sense and there's no pop sound on any outputs which is good.
My fingers are crossed for you that your issue is a simple one to fix. :)
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Thanks KM. Hopefully just a new cap!
Cheers
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Just to explain the logic a bit. You stated that the channel works fine without phantom ie. a dynamic mic. There is no DC to block so it should work. This is only on Channel 8 so the 48 V supply is out of the picture otherwise all channels would act the same. Too bad Mackie got cheap on the Phantom power circuit it doesn't have to spike. All high end gear has a soft start circuit for the 48 V. P. S. label all the screws and put them into baggies it will save you frustration in the end. The DL was not designed for service just another shortcoming. Leave plenty of time, you may have trouble finding the caps. I don't know type or value, most likely surface mount.
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Thanks WK. I'll certainly wait until I have plenty of down time. I can get away without it most of the time and I might even just pickup a couple of external phantom power units.
Cheers