Le 31-03-2013 11:02, Len Ovens a écrit : That must be the problem then. The higher the volume, the higher the 'ground' noise. The one to which the computer stuff is connected. The house plug. Which is not a plug, but a box. That one does not have a ground wire as others do. The two-AC plastic socket unit has no ground wire. Thanks for the information ! Indeed the problem now is that the Pulsar has no power. I shoudl start there. I've been using it for a long time like that ! ;-)) (or should it be: :-(() Was having fun though making music, but the noise was annoying. Obviously I know nothing about those phantom power units. Which one would you recommend ? Will it simply be in the XLR path: mic -> power -> 1010LT ? Also, now the passive DI box can be put to some other use. Would it accept the 1/4" output of a small VOX guitar amplifier ? What would be the difference in sound characteristics between using a DI box to the 1010LT 2nd XLR input vs. not using one and connecting the same VOX output to a regular 10101LT input ?

Le 31-03-2013 16:25, Fons Adriaensen a écrit : Thanks to Ardour, I know I am not hallucinating. More than 100 musical sketches made. No phantom on the mic.

On Sun, Mar 31, 2013 at 09:59:11PM -0700, Len Ovens wrote: I wouldn't be so sure. Electret mics can in theory produce a tiny signal even without power, but I don't think that's the case. More probably the mic pics ups some signal from the amplifier/speaker by magnetic induction. Regarding using the city water (or central heating pipes, or whatever) as a security ground: DON'T DO THAT. It would be illegal in almost all places, and you could easily kill or injure yourself or others if anything goes wrong. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow)

On Monday 01 April 2013 08:08:15 Len Ovens did opine: I doubt if it is 'floating', and we've had something resembling the NEC codebook for more than half a century now. What I would be concerned with in a house with wiring old enough to not have the 3rd, round pin in its duplexes, would some folks, and I have found this before in my travels, that the wider of the two slots in the duplex, which was supposed to be connected to the white wire which in post knob & ball wiring days, was always assumed to be the neutral side of the wiring. The black wire was supposed to be connected to the narrower slot, and was assumed to be the hot side of the line. By electricians... I can drive to what was a greasy spoon about a mile from here, in an old frame building, where every appliance in the kitchen was hot enough to buzz the help, the whole damned building is wired backwards! She finally moved her business about 2 years ago, into a much more modern building. THE IMPORTANT PART of this msg: At the lumberyards, like Lowes or Home Depot, in the electrical aisle, they have shirt pocket sized electrical 'Sniffers" not much bigger than a pen or pencil. Often their power switch is the pocket clip, you grab the end and squeeze the clip shut, then the other end has a plastic coated blade, and it will trill like a canary & blink an LED you can see when that blade is within 1 to 2 inches of a live wire. They sell for something in the ten dollar range, very cheap for something that can save your life by finding hot stuff that isn't supposed to be, like your refrigerator, often installed within reach of the usually well grounded stuff of the kitchen sink? So please get one ASAP. If not sooner. /THE IMPORTANT PART. The rest is optional but hopefully educational. I have 2, and they have saved me from many a potentially lethal shock over the last 25 years from stuff that was wired by folks who claimed to have known what they were doing. If you find a reverse wired duplex, where the wider slot is the hot side, it was probably wired bass-ackwards and has been since a roll of wire came on the premises 65 years ago. Yes, its been that long since I wired my parents house for electricity as it was being built in 1947. I was then 13 yo. Not knowing the white was ground by convention in the electrical trade, and already used to a grounded wire in a radio being black since I was already doing radio service for smoking money back then, I did it backwards & had to go back and fix it a month later when we were wiring the crawl space dugout for a water pump, the pump was a people buzzer when turned off. One of the steps in the education of Gene, who has now chased electrons to make therm do useful work all his life since, the last 50 in broadcasting. Oh, and I haven't had a cigarette now for 25 years. quit cold turkey, sick of being half sick with a cold that seemed to have hung on for more than its allotted 2 weeks. Maybe. One of my boyhood best friends followed in his fathers footsteps and got his Journeyman's card by the time he was 20. I had a problem & called him in on it (somehow life had put us back in the same town) when he was about 45, because I was at the time up to my butt in alligators as I had just become the CE at a tv station & the wiring to the studio lights was being a smoking problem child. Electrical stuff letting out the smoke usually means keeping fire extinguishers handy... He came in, we made all sorts of measurements & did a lot of head scratching for a couple hours one afternoon, then sat on the back stoop & had a beer, still playing what if games but reached no consensus as to why were were measuring many times the expected current in the neutral wires of one electrical box but not the other, the source of all the smoke & sparks. He was stumped as was I ATT. So I went home to dinner, still thinking about it, and the lights came on while I was scarfing up a hamburger steak. I went in about 5AM Sunday morning & verified the error. One of those 2 boxes was miss wired. Hard to fix as there wasn't a big breaker to kill the whole box that was miss wired, so I had to work on it hot. NBD to me. The problem was related to it being a 3 phase system. There was about 50 kw worth of lights in the studio in those days so there was 2 boxes full of 15 amp breakers. One box was a Federal, one box was a Square-D. I forget now which was which, but one box ran one phase A down the column of breakers on the left, and phase B down the 2nd column of breakers on the right, and one boxes bus was formed like a pair of combs teeth facing each other positioned between the teeth of the other phase, so that the top row was fed by phase one, the next row by phase 2, the 3rd row back on phase 1 etc to the bottom of the box. The electricians? who wired it weren't cognizant of the differences that would make and blindly wired both boxes so that the lamps, 1500 watt halogens, were wired up with a pair of 12 gauge wires to the hot side, and a single 14 gauge wire bringing the neutral back for BOTH lamps. So one box had 29 amps coming back up the flea weight 14 gauge neutral because both lamps were on the same phase, where the other box only had about 3.5 amps on this same neural wire because thats about what you get when you do the vector math for 2 legs of a 3 phase system. So the solution was to remove the right hand top wire, move it to the left hand side at row 2, take that wire back to the top right breaker, and basically do a step & repeat till I got to the bottom of the box. The breakers themselves could have been moved, easier, except that would have tangled up the wires even worse & the connections needed tightening anyway. Just good practice IMO. Problem solved for the life of the facility. Wrong boxes in the first place, should have been 3 phase boxes, but it was built by idiots working on the cheap & they would probably have had to special order the correct 3 phase boxes. A good electrician should have grokked that little detail instantly. But the vector math for a 3 phase system was not in his knowledge banks at all even if he was working days at one of the coal fired power station facilities being expanded that light up Los Angeles at the time, time being the late 1970's, place being Farmington NM. I never had the heart to tell him that his education was incomplete. Life leads folks down an infinite multitude of paths, always according the the Peter Principle I think. Or is that Parker? Never could (shrug) keep those 2 guys straight. [...] Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! My views <http://www.armchairpatriot.com/What%20Has%20America%20Become.shtml> "Plaese porrf raed." -- Prof. Michael O'Longhlin, S.U.N.Y. Purchase I was taught to respect my elders, but its getting harder and harder to find any...

Le 01-04-2013 09:58, Gene Heskett a écrit : The reply was an entertaining read ! Now if I understood the above correctly, a hot device would be one from which someone would get a shock by touching it, is it ?

On Mon, 2013-04-01 at 20:32 -0400, Gene Heskett wrote: There must be a difference for the potential to get shocked. German repair shops must use isolating transformer, to safeguard galvanic isolation! Btw. galvanic isolation also is the reason, that even cheap measuring bridges with a laboratory power supply, still need a battery. Direct current voltage <= 60 V and alternating voltage <= 25 V are values that in Germany are considered as riskless, for medicine there are anyway other values. The advantage of microphones with metal cases that are hot is, that nobody will sing or speak to close to the microphone ;p. Ok, some times a proximity effect is wanted, but usually it's a PITA that so many idiots touch the mics with their lips. Regards, Ralf

Le 01-04-2013 00:59, Len Ovens a écrit : Fortunately, no. It is only an extra wall the previous owner has made in the basement. The setup is now connected via a 3-prong extension to an outlet that is grounded. No More Ground Noise. This is so nice. I've gotten the specs from: http://www.m-audio.com/images/global/manuals/060817_PULSAR_UG_EN01.pdf This is the mic I have. It says Pulsar on it. Not Pulsar 2. Bought it in 2006 or so. Looks same as in the specs. Same accessories, same everything. The specs specifies a 48V phantom power. But from your comment and Fons', it seems that the phantom is actually the music recorded by it ! And this is not from a guitar amplifier. I record acoustic guitar and bass. Can have a magnet effect of some sort in there. So now this mystery remains. I was by the music shop today but they were closed. With the phantom and all, I'm not sure I'd get a phantom power supply on April Fools anyways. But the Pulsar mic works. Just recorded again some other things earlier today. Is it possible to probe the microphone's pins and by the impedance or something find out if it is made for having a phantom power supply ? I have a meter that I can put to good use.

On Mon, 2013-04-01 at 23:06 +0000, Fons Adriaensen wrote: 2013-04-02, so no April Fools' joke. ^^ I used cheap headphones as microphones for toying. Indeed a cheap dynamic microphone is the same, as a cheap Walkman's [1] headphone. Regarding to this perhaps neither those cheap mics, nor those cheap headphones are usable for serious recording. I wouldn't connect a microphone, that is better than a supermarket microphone to a headphone output! Measurements inside a circuit are only useful for some tests. However, pin 2 to pin 3 for a pseudo-Shure has got around 53 Ohm here and you don't need to be close with an ear to hear a loud crackling. The result is infinite between other pins, ergo no crackling. _But_ for a GRUNDIG GDM 12, a dynamic consumer mic that is really from the Stone Age, there's around 3K between all pins, crackling between all pins only when measuring with to low settings for the multimeter. To find out, if your mic is a dynamic mic or if it does need power, I wouldn't use a multimeter, but Google. Usually no ground = no noise and ground = possible noise. I only read less replies and I'm scary to recommend tricks regarding to ground issues, if the original poster is that clueless as for this thread, since it's to dangerous to play with ground. However, it's more likely that you get rid of noise, if you use a ground lift. At home I can do this by completely switching of the ground connection of a device but I don't need to do this, for the Brauner microphones we used capacitors, I guess it's forbidden to totally cut ground and I don't remember if just the shielding for the audio cables was lifted or also the ground cable between wall sockets and device. http://en.wikipedia.org/wiki/Ground_lift FWIW, if you're living in an old house, you even can get potential differences between devices, connected to different wall sockets, so even if everything should be grounded, there could be a potential difference. Don't ask me why there could be potential on ground, but it can happen, that you can get a shock, if you touch two metal cases hat are grounded. I guess house fires are often caused by bad electrical things. I even don't trust earth leakage circuit breakers in old houses. I'm living in an old house, while I don't get issues for audio, I'm anyway scary about the house electric, but I don't have the gear to check it. Because the original poster already has simple questions about the usage of a multimeter and a microphone, I recommend not to do handicrafts for the house electric. Regards, Ralf [1] In the Stone Age portable tape cassette players of all vendors were called "Walkman", the name originally belongs to the Sony's player.

On Tue, 2013-04-02 at 10:44 +0000, Fons Adriaensen wrote: Perhaps I'm overcareful, when an audio signal accidentally was that loud that the sound was played distorted by my headphones, I always feared that the relatively expensive headphones get damaged, but now they are 30 years old and still ok. Perhaps a microphone and maybe especially a more expensive one, could take it, but I wouldn't risk it. The MD 21 quasi is professional Telefunken quality of the 60s, capacity to withstand stresses and operational life span might be different to nowadays mics. I'm less overcareful with short circuits, but I anyway don't like the idea a kill-switch does work, http://www.google.de/imgres?q=killswitch+buckethead&hl=en&sa=X&… So as long as I'm not very rich, I try to avoid to do things that the gear is unprovided for, even if there is (nearly) no risk.