Tube Microphones info for the clueless - me.

EdgarHF

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I finally jumped into the home recording club yesterday by buying a focusriter scarlet 18i8 and a Warm Audio 251 large condenser tube microphone. I plugged it into the 18i8 I set it to cardioid on the transformer box. when I first plugged into XRL input one set at the default the microphone was so sensitive I could be heard walking on the other side of the room. I then that input to an inst setting. That seems much better. I have heard condenser mikes use phantom power but is this the case with a Tube Microphone that has a power transformer box? I am afraid to test it by pressing the 48v button. I have tried consulting the manual but I am guessing they are not taking the clueless like myself into account.
 

tubegeek

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I finally jumped into the home recording club yesterday by buying a focusriter scarlet 18i8 and a Warm Audio 251 large condenser tube microphone. I plugged it into the 18i8 I set it to cardioid on the transformer box. when I first plugged into XRL input one set at the default the microphone was so sensitive I could be heard walking on the other side of the room. I then that input to an inst setting. That seems much better. I have heard condenser mikes use phantom power but is this the case with a Tube Microphone that has a power transformer box? I am afraid to test it by pressing the 48v button. I have tried consulting the manual but I am guessing they are not taking the clueless like myself into account.

If it works with the phantom off, then it doesn't need the phantom on.

Does that Focusrite unit have a gain adjustment on the mic input? Turn it down. Does the condenser mic have its own integral preamp? Then yes, use the instrument (line level) input.
 

beyer160

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The mic’s power supply provides power, you don’t need To apply phantom on the interface. Switching it on shouldn’t hurt anything, though.

Also, the output from a tube mic power supply box will be at line level, so you shouldn’t need any preamp gain on the interface.
 

EdgarHF

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Does the condenser mic have its own integral preamp?

That is what I was trying to verify in the manual. I am guessing the transformer unit acts as a preamp. I am just trying to verify. I openly admitting I'm clueless.
 

tubegeek

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That is what I was trying to verify in the manual. I am guessing the transformer unit acts as a preamp. I am just trying to verify. I openly admitting I'm clueless.

Neither Warmaudio's web site nor the review on Sound On Sound at

https://www.soundonsound.com/reviews/warm-audio-wa-251

mention a preamp. But the 12AY7 tube acts as an impedance converter for sure and possibly does add some gain.

Output impedance 200 ohms, required input impedance is >2Kohms. An instrument input will work OK but a properly adjusted mic input may give you better signal/noise performance. An instrument input's much higher impedance (20K at least, probably even higher) is (technically) a potentially noisier input. It depends on how the Focusrite is designed but usually, your best bet is a purpose-designed mic input adjusted correctly.

Generally speaking, one of the fastest routes from noob to practical knowledge is to read Sound On Sound. Tape Op also highly recommended.

Nice choice of gear - good luck with your recordings!
 

Lawdawg

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Generally speaking, one of the fastest routes from noob to practical knowledge is to read Sound On Sound. Tape Op also highly recommended.

Nice choice of gear - good luck with your recordings!

100% on Sound on Sound -- it's really fantastic. Also check out the Gearslutz forum board. There are a ton of super knowledgeable folks on that forum (along with the usual idiots like me!) and if you search the threads you can find an answer to almost any recording question over there.

As to your specific question you will not need phantom power but I do believe you will still need a preamp -- just turn the gain down if the signal is too strong. Some mic preamps and mics themselves also allow you to pad the input for particularly loud sources like drums. Typically the only mics you can really damage by mistakenly turning on the phantom power are ribbon mics, but it's always good to check of course.
 

EdgarHF

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Neither Warmaudio's web site nor the review on Sound On Sound at

https://www.soundonsound.com/reviews/warm-audio-wa-251

mention a preamp. But the 12AY7 tube acts as an impedance converter for sure and possibly does add some gain.

Output impedance 200 ohms, required input impedance is >2Kohms. An instrument input will work OK but a properly adjusted mic input may give you better signal/noise performance. An instrument input's much higher impedance (20K at least, probably even higher) is (technically) a potentially noisier input. It depends on how the Focusrite is designed but usually, your best bet is a purpose-designed mic input adjusted correctly.

Generally speaking, one of the fastest routes from noob to practical knowledge is to read Sound On Sound. Tape Op also highly recommended.

Nice choice of gear - good luck with your recordings!

Thank you for link. Looks, like I need to figuratively go to school. Btw, the problem was too much gain. I bought, this mic and audio interface just to record a guitar and vocal. The cripple version of Pro Tools I received with the Scarlet does everything I need it to do for that purpose. But, now that I have a taste of recording I may end up going down a money pit. lol.
 

beyer160

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Typically the only mics you can really damage by mistakenly turning on the phantom power are ribbon mics

This is an urban legend.

Back before +48v phantom power was introduced in 1966, some older ribbon mics had center tapped transformers that would put DC power across the ribbon element if you applied phantom to them, which turned the ribbon element into the world's weakest fuse which would fail immediately.

Once phantom power became a thing in studios, mic manufacturers stopped center-tapping their transformers and the problem went away. Any ribbon mic made in the last 50 years will have no problem with phantom power, assuming you're not doing hot patching in a TT patch bay (which will short the phantom to the ribbon when you insert the cable) and your mic cables are in proper working order. Most older ribbons have been modified to resolve this issue, too. I used to use a Beyer 160 ribbon with a Daking channel strip with phantom permanently applied, and never had a problem.
 

Ed Driscoll

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As others have mentioned, since the mic has its own power supply, you won't need phantom power. Given that it's a modern reproduction of the Telefunken ELA M 251, if the phantom power is on when you plug the cable in, it shouldn't be the end of the world, but why take chances?

Condenser mics are much more sensitive to room noise and room tone than dynamic mics like the ubiquitous Shure SM58, so if your room isn't acoustically treated, you might want to start looking into that sooner rather than later. Depending upon the size of the room, even hanging duvets or moving blankets on all the walls should make it usable for vocals and acoustic guitar. (There maybe instruments such as percussion where a little room tone can be a good thing, and you can experiment with putting another mic in the corner to catch some of it on another track.)

According to Warm Audio's Webpage for the WA-251, it has multiple polar patterns, for cardioid, omni and figure-8. You can use those patterns to determine how much room tone and spill you want in the recording. Cardioid will give you the least, omni the most, and figure-8 is useful for recording duets, and for isolating noise using its null spot. Here's a pretty good primer on microphone polar patterns.
 
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Ed Driscoll

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Once phantom power became a thing in studios, mic manufacturers stopped center-tapping their transformers and the problem went away. Any ribbon mic made in the last 50 years will have no problem with phantom power, assuming you're not doing hot patching in a TT patch bay (which will short the phantom to the ribbon when you insert the cable) and your mic cables are in proper working order. Most older ribbons have been modified to resolve this issue, too. I used to use a Beyer 160 ribbon with a
Daking channel strip with phantom permanently applied, and never had a problem.

I bought my Shure KSM313 ribbon mic because they make a big point about how rugged the ribbons are. I figured if anybody is going to blowup a ribbon mic, it's going to be me! :lol:
 

Ed Driscoll

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Generally speaking, one of the fastest routes from noob to practical knowledge is to read Sound On Sound. Tape Op also highly recommended.

Their Websites contain a wealth of knowledge, and are well worth exploring. Sound on Sound's Studio SOS Book is an excellent primer for all facets of home recording, and frequent contributor Mike Senior's Mixing Secrets for the Small Studio is a very readable and practical guide for mixing on a home DAW. Both are available in the Kindle format if you want to have them on your computer as reference guides while you're working/experimenting.
 
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Ed Driscoll

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Thank you for link. Looks, like I need to figuratively go to school. Btw, the problem was too much gain. I bought, this mic and audio interface just to record a guitar and vocal. The cripple version of Pro Tools I received with the Scarlet does everything I need it to do for that purpose. But, now that I have a taste of recording I may end up going down a money pit. lol.

"May." :lol:

Seriously though, try to buy the best gear you can afford, so that you're not buying the same type of gear twice (or more).
 

EdgarHF

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Say goodbye to life as you know it.
Yes, life as I know it has already changed. I have since added the full standard version of pro tools and an AKAI MKP 225. My life is now trying to get the simplest things in Pro Tools to works only to immediately run into the next snag. Currently, I can not get a sound from the controller. Today will be another day of fruitless Google searches for fixes. I am desperately trying to keep at least a neutral attitude today:twisted:
 

Martin R

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Yes, life as I know it has already changed. I have since added the full standard version of pro tools and an AKAI MKP 225. My life is now trying to get the simplest things in Pro Tools to works only to immediately run into the next snag. Currently, I can not get a sound from the controller. Today will be another day of fruitless Google searches for fixes. I am desperately trying to keep at least a neutral attitude today:twisted:
Next, you'll read a review of the latest YoYoDine 3000 and think, "Hey, I could really use that".
 

GreatDaneRock

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I finally jumped into the home recording club yesterday by buying a focusriter scarlet 18i8 and a Warm Audio 251 large condenser tube microphone. I plugged it into the 18i8 I set it to cardioid on the transformer box. when I first plugged into XRL input one set at the default the microphone was so sensitive I could be heard walking on the other side of the room. I then that input to an inst setting. That seems much better. I have heard condenser mikes use phantom power but is this the case with a Tube Microphone that has a power transformer box? I am afraid to test it by pressing the 48v button. I have tried consulting the manual but I am guessing they are not taking the clueless like myself into account.
No phantom power! the power supply box will provide it, normally tube microphones have unique phantom power requirements that not always equals 48 volts DC. Also i do not recommend lowering the input gain by pressing instrument or line, instead use the pad switch, that's what it's there for.

Tube microphones are sensitive and the issue that you're in the wrong environment for such a microphone. you need a properly isolated environment and that's hard to achieve on a home or apartment, that's the reality of it.
 

GreatDaneRock

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The mic’s power supply provides power, you don’t need To apply phantom on the interface. Switching it on shouldn’t hurt anything, though.

Also, the output from a tube mic power supply box will be at line level, so you shouldn’t need any preamp gain on the interface.
Not true, the power supply is just to provide the proper phantom power voltage and polar pattern switching capabilities. It will still put out a mic level signal that needs to be connected to a proper preamplifier.
 

GreatDaneRock

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That is what I was trying to verify in the manual. I am guessing the transformer unit acts as a preamp. I am just trying to verify. I openly admitting I'm clueless.
No it doesn't, the power supply box is not a preamp not at all. I'm a professional sound engineer and make a living teaching this stuff at a very prestigious School.
 

EdgarHF

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No it doesn't, the power supply box is not a preamp not at all. I'm a professional sound engineer and make a living teaching this stuff at a very prestigious School.

Thanks for the info. The microphone has been working, but I will be ordering a microphone preamp today. I did do some research based on your post and from what I understand, and I could be wrong, is my audio interface has a preamp. It has a preamp, but I will be losing the benefits of the tube microphone without an external preamp that would plug into the back of my scarlet bypassing the internal preamp.
 
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beyer160

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Not true, the power supply is just to provide the proper phantom power voltage and polar pattern switching capabilities. It will still put out a mic level signal that needs to be connected to a proper preamplifier.

You are correct that the output will be mic level, I misstated my earlier post- it should have read, "the output from a tube mic power supply box will be nearly line level, so you shouldn’t need any preamp gain on the interface." (I'd go back and change it, but I can't edit the post now for some reason).

What I was trying to say is that the output of the mic will be really hot, so you don't need to crank the gain as if it was a 58.

Incidentally, I have patched a tube mic directly to tape on two occassions- the first was a U67 patched directly to an Otari MTR90, the second was a Rode Classic to a DA88.
 
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