Very Inexperienced & Working on Audio Book

[flynwill]

In general that manual is silent about the voltage of the "mic power" (the label on the button). However the block diagram schematic on page 11 shows pins 2 & 3 of the XLR mic connectors connected to 48V through a pair of resistors (or what I assume are resisters) of undefined value. So from that I would conclude it is 48V phantom power. If you have a multi-meter of any sort available you could check the voltage between pin 2 and pin 1 and the voltage between pin 3 and pin 1 with the mic power turned on and if it is the listed 48V. If you have a mic cable that where you can open up the male connector, you could also check the voltage with your microphone connected, it should be more than 20 volts in that case.

[macmex]

Okay. Thank you, I'll see what I can do.

George

[kozikowski]

OK. That works for me. You should be able to run the Lifter by selecting MIC-POWER on the mixer. You will not need the external Phantom Generator. Cable the Lifter straight into the mixer.

This should boost the sound enough to get an occasional mixer yellow flash and perform without shouting.

Should we get that far, then it's connect the computer time.

Koz

[kozikowski]

If you're handy with a voltmeter, it can be 48-ish volts open circuit. They just have to get close. All modern microphones have a range of acceptable voltages, and this system has to be able to run over long cables. 12 is not close.

Yes, they're resistors, usually precision balanced units so as not to upset the balance of the sound signal.

By the way, do not change the MIC-POWER button while the mixer is connected to anything you care about. Some mixers make a loud thump or pop. If you happen to be connected to a stage sound system when you do that, you could launch one of the performers.

Koz

[macmex]

Just an update. I am a little rusty on the voltmeter. Used to use one about 20 years ago and could probably manage. But I brought the mixer in to work, where a friend of mine works on medical equipment. He said he'd check the voltage on the mic power. But, looks like it will be tonight or tomorrow before I find out, now that I asked.

George

[kozikowski]

It's not critical now. The presence of 48 volts on the schematic diagram is good for me. I know how the basic electronic design works.

A measurement is taken between pin 1 and pin 2 and then a second measurement between pin 1 and pin 3 in the XLR. Both should read about 48 volts. If you have a strong flashlight, the pins should be labeled on the XLR plastic.

That's how Phantom Power works. The microphone signal is entirely between pins 2 and 3 and hardly involving pin 1 at all. Phantom Power involves pin 1 and the combination of 2 and 3. Done properly, the two systems are invisible to each other. Each is a "phantom."

Amaze your friends.

Let us know. You know what to look for. With Mic Power switched on, it should be possible to get occasional yellow lights without shouting into the microphone.

Koz

[macmex]

Wish I could "amaze them." But he kept it. Will return it in the morning.

George

[kozikowski]

And from basic electronics, if you measure between pins 2 and 3, you should get nothing. Both pins are at 48 volts, but the difference between them is zip.

Koz

[macmex]

Alright. Ready to move forward. The voltage is 46.7.

George

[macmex]

I just spent some time recording. I connected the SM7A mic to the Cloudlifter and then to the Folio Notepad. I used the mic power from the Folio Notepad. I did two recordings, one with the volume set at 9 and the other set at 5 (on the bottom left knob of the mixer). I used our Sony headphones each time. What I don't understand, is that I could hear myself speaking into the mic during the first recording but while doing the second, the headphones were silent. They worked fine for playback in both cases.

I did do one recording without the Cloudlifter. The noise level was greater. I didn't keep a copy of that file.

Here are the two files I saved.

Test4_28_2015_SM7A_FolioNotepadSpirit_CloudlifterCL-1_built_in_phantom_mic_power_Vol9.wav

(1.84 MiB) Downloaded 25 times

Test4_28_2015_SM7A_FolioNotepadSpirit_CloudlifterCL-1_built_in_phantom_mic_power_Vol9.wav

(1.84 MiB) Downloaded 25 times

George