Eric Toline Posted May 11, 2018 Report Share Posted May 11, 2018 4 minutes ago, Rick Reineke said: The soon-to-be-released F8n allegedly has mic/line switchable XLRs. Yes it does. Quote Link to comment Share on other sites More sharing options...
Sprotnik Posted May 11, 2018 Report Share Posted May 11, 2018 So... I have already checked it with a volt meter. And, yes. F8 stops feeding the microphone with the pantom power when you disable a track for recording. the only thing is that it takes a while to go from 48v (in fact it has 46v) to 0v. When you enable the track it starts to phantom power again. I think it has good reasons to do it. You can unplug the microphone safely and the power consumption of the batteries is optimized. Quote Link to comment Share on other sites More sharing options...
Johnny Karlsson Posted May 11, 2018 Report Share Posted May 11, 2018 I must be very un-safely, because I have plugged and unplugged my mics for over 30 years with p48 on. Quote Link to comment Share on other sites More sharing options...
IronFilm Posted May 13, 2018 Report Share Posted May 13, 2018 On 5/11/2018 at 11:52 PM, Sprotnik said: Hi. old topic but I have a doubt about the Zoom f8 that I can´t solve reading the manual or searching in the web (maybe I´m not searching the appropiate words...) the question is: when the phantom power in one track is activated, is it turned off automatically when you push the button of "disable for recording" of that track? when you disable for recording one track it goes mute, but i don´t know if it stops giving phantom power to the microphone. regards! Why would you want this feature? Edit: heh, saw the responses above now. Quote Link to comment Share on other sites More sharing options...
Glen Trew Posted May 13, 2018 Report Share Posted May 13, 2018 On 5/11/2018 at 10:08 AM, Sprotnik said: So... I have already checked it with a volt meter. And, yes. F8 stops feeding the microphone with the pantom power when you disable a track for recording. the only thing is that it takes a while to go from 48v (in fact it has 46v) to 0v. When you enable the track it starts to phantom power again. I think it has good reasons to do it. You can unplug the microphone safely and the power consumption of the batteries is optimized. I imagine that feature is to save on power consumption, the thought being that if the track is disabled, there is no need to have the 48V DC-DC converter on. Regarding the safety of plugging and unplugging a mic with phantom power turned on, there is no need for concern. Quote Link to comment Share on other sites More sharing options...
David Waelder Posted May 17, 2018 Report Share Posted May 17, 2018 On 5/13/2018 at 10:33 AM, Glen Trew said: Regarding the safety of plugging and unplugging a mic with phantom power turned on, there is no need for concern. Like others, I've connected and disconnected phantom microphones many times without any harm or concern. But there is an issue I think worth mentioning. With XLR connectors, there is no reason to be concerned. And, ordinarily there is no reason that a phantom microphone would be connected with anything else. However, when I was having a patch panel fabricated for my cart, I was advised to use XLR connections in that panel instead of the more usual phone connections. With the phone connections, it is possible to have a momentary short on the phantom power lines when inserting or removing the connector. That doesn't happen with XLR connectors with pins that keep the connections discrete. David Quote Link to comment Share on other sites More sharing options...
Constantin Posted May 17, 2018 Report Share Posted May 17, 2018 While microphones are fine being plugged and unplugged with phantom power on, other equipment may not be, such as wireless receivers. The SRa version of Lectro for example had that problem for a while, so it may be good practice to always turn phantom off when unplugging a mic Quote Link to comment Share on other sites More sharing options...
Glen Trew Posted May 25, 2018 Report Share Posted May 25, 2018 On 5/16/2018 at 8:23 PM, David Waelder said: Like others, I've connected and disconnected phantom microphones many times without any harm or concern. But there is an issue I think worth mentioning. With XLR connectors, there is no reason to be concerned. And, ordinarily there is no reason that a phantom microphone would be connected with anything else. However, when I was having a patch panel fabricated for my cart, I was advised to use XLR connections in that panel instead of the more usual phone connections. With the phone connections, it is possible to have a momentary short on the phantom power lines when inserting or removing the connector. That doesn't happen with XLR connectors with pins that keep the connections discrete. David Hi David, Proper TT phone plug patch panels (TT is the smaller than the original 1/4-inch plugs, standing for "Tiny Telephone") may cause a short of the phantom supply voltage, but this is of no concern because the phantom voltage always has two 6.8k in-line current limiting resistors that keep the maximum current of a 48V supply at or below 10mA. I have actual TT patch panels in carts I made in the late 80s, early 90s, and I've been hot patching 48V phantom with them for 30 years now with no problem. Of the 3000 recording studios in Nashville, the more sophisticated ones have TT patch panels that route 48V phantom to microphones. This brings up a topic that deserves it's own thread about patch panels. Referring to XLR connector panels as "patch panels" is incorrect, as they are merely extension panels. "Patch Panel" refers to the ability to route through, interupt, not interupt, or connect. XLR panels can only connect, so, convenient as they are, they are not patch panels. That said, there are numerous advantages of patch panels, which will hopefully be realized again someday. Quote Link to comment Share on other sites More sharing options...
Philip Perkins Posted May 25, 2018 Report Share Posted May 25, 2018 Yes--big cheers for normalling.... Quote Link to comment Share on other sites More sharing options...
mono Posted May 25, 2018 Report Share Posted May 25, 2018 On 5/16/2018 at 7:23 PM, David Waelder said: Like others, I've connected and disconnected phantom microphones many times without any harm or concern. But there is an issue I think worth mentioning. With XLR connectors, there is no reason to be concerned. And, ordinarily there is no reason that a phantom microphone would be connected with anything else. However, when I was having a patch panel fabricated for my cart, I was advised to use XLR connections in that panel instead of the more usual phone connections. With the phone connections, it is possible to have a momentary short on the phantom power lines when inserting or removing the connector. That doesn't happen with XLR connectors with pins that keep the connections discrete. David 2 hours ago, Glen Trew said: Hi David, Proper TT phone plug patch panels (TT is the smaller than the original 1/4-inch plugs, standing for "Tiny Telephone") may cause a short of the phantom supply voltage, but this is of no concern because the phantom voltage always has two 6.8k in-line current limiting resistors that keep the maximum current of a 48V supply at or below 10mA. I have actual TT patch panels in carts I made in the late 80s, early 90s, and I've been hot patching 48V phantom with them for 30 years now with no problem. Of the 3000 recording studios in Nashville, the more sophisticated ones have TT patch panels that route 48V phantom to microphones. This brings up a topic that deserves it's own thread about patch panels. Referring to XLR connector panels as "patch panels" is incorrect, as they are merely extension panels. "Patch Panel" refers to the ability to route through, interupt, not interupt, or connect. XLR panels can only connect, so, convenient as they are, they are not patch panels. That said, there are numerous advantages of patch panels, which will hopefully be realized again someday. Also see: https://www.lectrosonics.com/Support/component/com_fsf/Itemid,714/tag,Wireless, 48, phantom power, damage, receiver/view,faq/# https://secure.aes.org/forum/pubs/journal/?ID=18 http://www.thatcorp.com/datashts/AES7909_48V_Phantom_Menace_Returns.pdf Quote Link to comment Share on other sites More sharing options...
Constantin Posted May 25, 2018 Report Share Posted May 25, 2018 37 minutes ago, mono said: Also see: https://www.lectrosonics.com/Support/component/com_fsf/Itemid,714/tag,Wireless, 48, phantom power, damage, receiver/view,faq/# Just to elaborate on my previous post then, regarding the phantom power and Lectro units: I had two units, one damaged by myself and one damaged by a colleague, and we both had left phantom power engaged in hectic situations. And in both cases the output stage got damaged in that it became very very quiet. I sent both to the Lectro distributor in Germany, Ambient recording, and they confirmed the issue and the *likely* cause and they repaired and definitely invoiced something. ... Quote Link to comment Share on other sites More sharing options...
LarryF Posted May 25, 2018 Report Share Posted May 25, 2018 On 5/16/2018 at 8:30 PM, Constantin said: While microphones are fine being plugged and unplugged with phantom power on, other equipment may not be, such as wireless receivers. The SRa version of Lectro for example had that problem for a while, so it may be good practice to always turn phantom off when unplugging a mic The original SR used (new to us) 0402 size surface mount resistors in the output circuits. They were rated at 1/20 of a Watt and should have been fine. Then we started getting damaged units from the field (nothing like reality) and we (I) were flummoxed as to why the output resistors were failing. All fault condition scenarios were accounted for and the resistors should not have failed. Further, this was an output stage topology that we had used for years. Once the resistors blew open, the rest of the output circuitry blew also. After some more units came in with the same failures, I decided reality owes us no explanations; it just is. The units were modified with 1/8 Watt 0805 parts and the problems ceased. I still don't understand what was happening. But resistors are very cheap and the problem went away. Incidentally, this was (is) an extended warranty repair. It should have been done at no charge. Best Regards, Larry Fisher p.s. It's still good practice to turn phantom power off when connecting to non mic audio circuits. protection Quote Link to comment Share on other sites More sharing options...
David Waelder Posted May 26, 2018 Report Share Posted May 26, 2018 Thank you all (Glen, Mono, Constantine, Larry F) for the education. It would seem that the issue is a bit more complex than I had realized. My take away from all of this is that: 1. Damage to a microphone (as distinct from damage to other components) from connection to phantom power is most unlikely because there is protection built into the circuit. 2. Notwithstanding this precaution, the real world sometimes presents unwelcome surprises. 3. The use of XLR connectors may reduce the likelihood of a momentary short but it is not an absolute protection. Momentary shorts can happen even with XLR connections. Is this a fair summary? David Quote Link to comment Share on other sites More sharing options...
Philip Perkins Posted May 26, 2018 Report Share Posted May 26, 2018 Re p48 and non-mic circuits: it used to be that gear like mixers etc could be damaged by being connected to old school betacam style camera audio inputs if the p48 was on. This didn't happen to me with robustly xformer protected gear like Shure FP mixers, more with electronically balanced gear (mixers, signal processing). Whose outputs I quickly learned to protect with trafos..... Quote Link to comment Share on other sites More sharing options...
Vincent R. Posted May 27, 2018 Report Share Posted May 27, 2018 17 hours ago, Philip Perkins said: Re p48 and non-mic circuits: it used to be that gear like mixers etc could be damaged by being connected to old school betacam style camera audio inputs if the p48 was on. This didn't happen to me with robustly xformer protected gear like Shure FP mixers, more with electronically balanced gear (mixers, signal processing). Whose outputs I quickly learned to protect with trafos..... Yes and to get the topic back to the Zoom's, the F4 and I believe F8 too, are known for that, in protected XLR outputs. I believe there is an official warning for that on Zoom's website. Quote Link to comment Share on other sites More sharing options...
Tambongo Posted May 27, 2018 Report Share Posted May 27, 2018 The F8 failed when it got cold. I dont remember how cold it was, but maybe around -5c? I would not turn on again before it was warm enough. Quote Link to comment Share on other sites More sharing options...
IronFilm Posted December 17, 2018 Report Share Posted December 17, 2018 Zoom F8 being used extensively on "Mission Impossible": https://magazine.local695.com/magazine/fall-2018/mission-impossible-fallout Quote Link to comment Share on other sites More sharing options...
Vincent R. Posted December 17, 2018 Report Share Posted December 17, 2018 On 5/27/2018 at 12:37 PM, Tambongo said: The F8 failed when it got cold. I dont remember how cold it was, but maybe around -5c? I would not turn on again before it was warm enough. You sure it was the recorder and not the battery? I used the f8 a couple of years ago without problems in worse conditions. Quote Link to comment Share on other sites More sharing options...
IronFilm Posted February 20, 2019 Report Share Posted February 20, 2019 On 5/26/2018 at 11:54 AM, LarryF said: The original SR used (new to us) 0402 size surface mount resistors in the output circuits. They were rated at 1/20 of a Watt and should have been fine. Then we started getting damaged units from the field (nothing like reality) and we (I) were flummoxed as to why the output resistors were failing. All fault condition scenarios were accounted for and the resistors should not have failed. Further, this was an output stage topology that we had used for years. Once the resistors blew open, the rest of the output circuitry blew also. After some more units came in with the same failures, I decided reality owes us no explanations; it just is. The units were modified with 1/8 Watt 0805 parts and the problems ceased. I still don't understand what was happening. But resistors are very cheap and the problem went away. Incidentally, this was (is) an extended warranty repair. It should have been done at no charge. Best Regards, Larry Fisher p.s. It's still good practice to turn phantom power off when connecting to non mic audio circuits. protection So did later model original SR receivers get the 1/8 Watt 0805 parts before they even left the factory once you realized the problem, at what point in the serial numbers did they see this change? Quote Link to comment Share on other sites More sharing options...
LarryF Posted February 20, 2019 Report Share Posted February 20, 2019 13 hours ago, IronFilm said: So did later model original SR receivers get the 1/8 Watt 0805 parts before they even left the factory once you realized the problem, at what point in the serial numbers did they see this change? Once we (I) realized the problem, everything was changed, even units on the shelf, theory be Damned. Units that come in for repair are also updated. This is a mandatory, no charge, no time limit update. I will have to get Wes Herron, VP of production to get us the serial numbers and/or dates. Best Regards, Larry Fisher Quote Link to comment Share on other sites More sharing options...
Constantin Posted February 20, 2019 Report Share Posted February 20, 2019 It wasn’t just the original SR, though, in my case it was an SRa. I never had an SR and I seem to remember they were never sold in Europe? Ambient were well familiar with the issue and turned it around really quickly. Quote Link to comment Share on other sites More sharing options...
WesH Posted February 21, 2019 Report Share Posted February 21, 2019 Hi all, The higher-rated 1/8W 0805 parts were incorporated into the circuit boards in March of 2011 effective with the following start serial numbers: SRA: 101404 SRA5P: 61306 SRA/E01: 476 SRA5P/E01: 50320 Best regards, Wes Herron Lectrosonics Quote Link to comment Share on other sites More sharing options...
Constantin Posted February 22, 2019 Report Share Posted February 22, 2019 Interesting. I do indeed have lower serials than those listed. Anyway, that’s long ago and those receivers have been flawless since then. Still in use all the time after an SRB upgrade Quote Link to comment Share on other sites More sharing options...
LarryF Posted February 22, 2019 Report Share Posted February 22, 2019 3 hours ago, Constantin said: Interesting. I do indeed have lower serials than those listed. Anyway, that’s long ago and those receivers have been flawless since then. Still in use all the time after an SRB upgrade Hi Constantin, Anytime they get into the tentacles of mothership; upgrade, repair, accidentally sent them to the wrong address; the larger resistors would have been installed. Best Regards, Larry Fisher Quote Link to comment Share on other sites More sharing options...
Constantin Posted February 22, 2019 Report Share Posted February 22, 2019 7 hours ago, LarryF said: Hi Constantin, Anytime they get into the tentacles of mothership; upgrade, repair, accidentally sent them to the wrong address; the larger resistors would have been installed. Best Regards, Larry Fisher Oh great. Mine have had the larger resisitors eversince I plugged them into an active phantom power supply The others were damaged by a friend who I had loaned them to, of course... Quote Link to comment Share on other sites More sharing options...
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