Topic: coupla n00b questions (phantom AT853 content)

[CHURCH-AUDIO]

When I was talking about "battery" I was referring to a 9 volt battery box. I hate to tell people this but we take a three wire capsule and "convert it" to two wire using a special design that I have come up with. Most people are using  “the standard” mod we have found another way that reduces the THD distortion by 10%. That number does not sound like much but it's allot, it does reduce the gain by 3-5 db but with our preamp our customers do not notice the difference. Also to measure distortion we take our DuPont calibrator run it at 1K @114dB that has a self distortion as measured by our earthworks m50 of less then 0.003%. We then couple the mic under test to this calibrator and we then input the output of the capsule into a simple battery box and using WINAUDIOMLS lab addition measure the harmonic distortion. This is the only accurate way to measure distortion an oscilloscope is not sensitive enough to see this distortion, and your ears can hear most distortion but we feel,  Seeing a screen with a number and using the substitution method is the best way we have found to measure it. Most mic manufactures use a similar method but some fudge the numbers just a tad to look better on a spec sheet. like for example they might sweep around until the find the frequency that has the least amount of distortion and use that as a figure. We feel that is  very misleading we use 1K it is the industry standard. That being said mics are most likely to distort at low frequencies but with a cardioid mic this is less of a problem then with an omni.

Chris Church

The AT mics will run on batterys they have a max supply voltage or bias voltage of 12 volts dc. Even when you use a phantom preamp that comes with the mics they are only supplying 10 volts. So there is no advantage over the phantom or non phatom. Infact the only thing the preamp does is act as an impedence converter to convert the high imp to low imp 3 pin XLR. So if you are not going to use a high end preamp with XLR inputs, don't bother with the phantom option. If how ever you want to use a preamp with XLR imputs you must use the phantom interface. Hope this helps there are lots of great mic builders out there that make great mics like me for example everyone makes a good product to one degree or another but look around first not just at me but other companyies as well

Chris Church
Church-Audio

i would have to disagree sir.  the specs from AT give a higher max spl: 135dB (vs 121dB with battery), bettery dynamic range: 106dB (vs 94dB with battery), less impedance: 200 ohms (vs 270 ohms with battery) and lower open circuit sensitivity: -44 dB /6.3mV (vs -45dB /5.6mV with battery).

and then there is the whole 'actually listening to it' which pretty much makes the techie talk above self explainatory.  phantom powered, these mics are a completely different caliber then when run off traditional battery packs.

The reason for battery different than phantom is that the battery (in the AT8531 adapter) uses 1.5V only (a single AA cell), while the phantom powering gives about 9V.  (I've measured it!!).

So, if you have a proper (9v) 3-wire battery box you will get as good as phantom, at least in terms of volume level.  (The phantom adapters *might* be slightly better in terms of output impedance, eg., driving long cables to a mixer, but for anything we do, the battery box should be just fine.)

  Richard

[poorlyconditioned]

When I was talking about "battery" I was referring to a 9 volt battery box. I hate to tell people this but we take a three wire capsule and "convert it" to two wire using a special design that I have come up with. Most people are using  “the standard” mod we have found another way that reduces the THD distortion by 10%. That number does not sound like much but it's allot, it does reduce the gain by 3-5 db but with our preamp our customers do not notice the difference. Also to measure distortion we take our DuPont calibrator run it at 1K @114dB that has a self distortion as measured by our earthworks m50 of less then 0.003%. We then couple the mic under test to this calibrator and we then input the output of the capsule into a simple battery box and using WINAUDIOMLS lab addition measure the harmonic distortion. This is the only accurate way to measure distortion an oscilloscope is not sensitive enough to see this distortion, and your ears can hear most distortion but we feel,  Seeing a screen with a number and using the substitution method is the best way we have found to measure it. Most mic manufactures use a similar method but some fudge the numbers just a tad to look better on a spec sheet. like for example they might sweep around until the find the frequency that has the least amount of distortion and use that as a figure. We feel that is  very misleading we use 1K it is the industry standard. That being said mics are most likely to distort at low frequencies but with a cardioid mic this is less of a problem then with an omni.

Chris Church

The AT mics will run on batterys they have a max supply voltage or bias voltage of 12 volts dc. Even when you use a phantom preamp that comes with the mics they are only supplying 10 volts. So there is no advantage over the phantom or non phatom. Infact the only thing the preamp does is act as an impedence converter to convert the high imp to low imp 3 pin XLR. So if you are not going to use a high end preamp with XLR inputs, don't bother with the phantom option. If how ever you want to use a preamp with XLR imputs you must use the phantom interface. Hope this helps there are lots of great mic builders out there that make great mics like me for example everyone makes a good product to one degree or another but look around first not just at me but other companyies as well

Chris Church
Church-Audio

i would have to disagree sir.  the specs from AT give a higher max spl: 135dB (vs 121dB with battery), bettery dynamic range: 106dB (vs 94dB with battery), less impedance: 200 ohms (vs 270 ohms with battery) and lower open circuit sensitivity: -44 dB /6.3mV (vs -45dB /5.6mV with battery).

and then there is the whole 'actually listening to it' which pretty much makes the techie talk above self explainatory.  phantom powered, these mics are a completely different caliber then when run off traditional battery packs.

The reason for battery different than phantom is that the battery (in the AT8531 adapter) uses 1.5V only (a single AA cell), while the phantom powering gives about 9V.  (I've measured it!!).

So, if you have a proper (9v) 3-wire battery box you will get as good as phantom, at least in terms of volume level.  (The phantom adapters *might* be slightly better in terms of output impedance, eg., driving long cables to a mixer, but for anything we do, the battery box should be just fine.)

  Richard

Can you elighten us?  What circuit are you using?  There are two ways I know of (for "2-wire" mics):
1) adding a source resistor, eg., 1kR, to reduce gain (and hence distortion)
2) do "Linkwitz's" mod, that is, run in source follower, but with two wires and a positive ground.

The first is nice because it is still compatable with standard "2-wire" battery boxes and "plug in power".  The second is incompatable (needs a special battery box), but still uses just two wires (nice when you're trying to setup mics using standard cables, like those in headphones, etc).

Please let us know.  I've said this before, and I'll say it again, people here are willing to pay for gear/mods, but you've got to tell us what is inside.

Thanks,
  Richard

[CHURCH-AUDIO]

Hi Richard I use OPA2227A opamp for my preamp that provides -00 to +20db of gain via a dual alps pot. In a very cute little package about the size of pack of cigarettes. In the preamp we use nothing but 1% resistors Metal film and we also use epoxy to coat our circuit so no one steals it . You know it’s hard to keep others from taking your ideas and selling them for profit. We have worked hard to get this preamp to have a very low distortion very low distortion of 0.002% this preamp does not have a clip light I think they are lame. They tell you when the preamp is distorting but give you no reference as to when the recorder is distorting. We feel that it’s more important to watch the recorder then our little box. As far as the mod we do to our mics and anyone else's mics that’s top secret ask Audio Technica what they do to the capsules they purchase to mod them. I doubt you would get an answer. This is not bullshit my mod works and works well and it’s not the Linkwitz mod that everyone does but in order for this to work it has to be a three wire capsule or at least one that I can make three wire. We use nothing but the best parts all of our products are hand built and made to last.

Chris Church

When I was talking about "battery" I was referring to a 9 volt battery box. I hate to tell people this but we take a three wire capsule and "convert it" to two wire using a special design that I have come up with. Most people are using  “the standard” mod we have found another way that reduces the THD distortion by 10%. That number does not sound like much but it's allot, it does reduce the gain by 3-5 db but with our preamp our customers do not notice the difference. Also to measure distortion we take our DuPont calibrator run it at 1K @114dB that has a self distortion as measured by our earthworks m50 of less then 0.003%. We then couple the mic under test to this calibrator and we then input the output of the capsule into a simple battery box and using WINAUDIOMLS lab addition measure the harmonic distortion. This is the only accurate way to measure distortion an oscilloscope is not sensitive enough to see this distortion, and your ears can hear most distortion but we feel,  Seeing a screen with a number and using the substitution method is the best way we have found to measure it. Most mic manufactures use a similar method but some fudge the numbers just a tad to look better on a spec sheet. like for example they might sweep around until the find the frequency that has the least amount of distortion and use that as a figure. We feel that is  very misleading we use 1K it is the industry standard. That being said mics are most likely to distort at low frequencies but with a cardioid mic this is less of a problem then with an omni.

Chris Church

The AT mics will run on batterys they have a max supply voltage or bias voltage of 12 volts dc. Even when you use a phantom preamp that comes with the mics they are only supplying 10 volts. So there is no advantage over the phantom or non phatom. Infact the only thing the preamp does is act as an impedence converter to convert the high imp to low imp 3 pin XLR. So if you are not going to use a high end preamp with XLR inputs, don't bother with the phantom option. If how ever you want to use a preamp with XLR imputs you must use the phantom interface. Hope this helps there are lots of great mic builders out there that make great mics like me for example everyone makes a good product to one degree or another but look around first not just at me but other companyies as well

Chris Church
Church-Audio

i would have to disagree sir.  the specs from AT give a higher max spl: 135dB (vs 121dB with battery), bettery dynamic range: 106dB (vs 94dB with battery), less impedance: 200 ohms (vs 270 ohms with battery) and lower open circuit sensitivity: -44 dB /6.3mV (vs -45dB /5.6mV with battery).

and then there is the whole 'actually listening to it' which pretty much makes the techie talk above self explainatory.  phantom powered, these mics are a completely different caliber then when run off traditional battery packs.

The reason for battery different than phantom is that the battery (in the AT8531 adapter) uses 1.5V only (a single AA cell), while the phantom powering gives about 9V.  (I've measured it!!).

So, if you have a proper (9v) 3-wire battery box you will get as good as phantom, at least in terms of volume level.  (The phantom adapters *might* be slightly better in terms of output impedance, eg., driving long cables to a mixer, but for anything we do, the battery box should be just fine.)

  Richard

Can you elighten us?  What circuit are you using?  There are two ways I know of (for "2-wire" mics):
1) adding a source resistor, eg., 1kR, to reduce gain (and hence distortion)
2) do "Linkwitz's" mod, that is, run in source follower, but with two wires and a positive ground.

The first is nice because it is still compatable with standard "2-wire" battery boxes and "plug in power".  The second is incompatable (needs a special battery box), but still uses just two wires (nice when you're trying to setup mics using standard cables, like those in headphones, etc).

Please let us know.  I've said this before, and I'll say it again, people here are willing to pay for gear/mods, but you've got to tell us what is inside.

Thanks,
  Richard

[poorlyconditioned]

Hi Richard I use OPA2227A opamp for my preamp that provides -00 to +20db of gain via a dual alps pot. In a very cute little package about the size of pack of cigarettes. In the preamp we use nothing but 1% resistors Metal film and we also use epoxy to coat our circuit so no one steals it . You know it’s hard to keep others from taking your ideas and selling them for profit. We have worked hard to get this preamp to have a very low distortion very low distortion of 0.002% this preamp does not have a clip light I think they are lame. They tell you when the preamp is distorting but give you no reference as to when the recorder is distorting. We feel that it’s more important to watch the recorder then our little box. As far as the mod we do to our mics and anyone else's mics that’s top secret ask Audio Technica what they do to the capsules they purchase to mod them. I doubt you would get an answer. This is not bullshit my mod works and works well and it’s not the Linkwitz mod that everyone does but in order for this to work it has to be a three wire capsule or at least one that I can make three wire. We use nothing but the best parts all of our products are hand built and made to last.

Chris Church

Hey, thanks for the information.

So, you've got two miniXLR connectors on your box, right?  Does that mean I can plug standard AT mics in there?  (Ie., + on pin 3, audio on pin 2, and shield on pin 1)  If so, I (and several others here) would be interested in quotes for: 1) battery box alone (ie., 3-wire battery box), 2) box with OPA opamp (and 3-wire power).  Please post those two prices here.

Thanks,
  Richard

[willndmb]

here is another 853 question
if you take SP 853 that end in 1/8 plug
and plugged them into a ua5 with a 1/8f > dual xlr
could you use the phantom power from the ua5?
would that be the same as a 3 wire box, just on a large scale?

[poorlyconditioned]

here is another 853 question
if you take SP 853 that end in 1/8 plug
and plugged them into a ua5 with a 1/8f > dual xlr
could you use the phantom power from the ua5?
would that be the same as a 3 wire box, just on a large scale?

No!  You cannot give AT853 mics phantom power directly.  That will burn them out!

You need either a battery box, plug in power (from a MD, etc), or a phantom adapter.

The adapter steps the phantom power (48V) down to a lower voltage (eg., 9V) that the mics use.

  Richard

[George]

In sound quality, there is a night and day difference between non-phantom power at853's and phantom powered at853's.  It's like removing a veil off of them (i'm talking about cardioids).  Bass is punchy, highs sparkle...total different beast compared to at853's>sp bbox which sounded muffled and rolled off highs. 

[CHURCH-AUDIO]

Prices for just a battery box with mini XLR connectors is $100.00 + shipping. The preamp version with 00-to+20 db with adjustable gain control is $225.00 + shipping, if you want us to put some ends on your mics and do our mod its $50 extra. The mics must be three wire we can also do three wire to two wire adaptors with our mod built in for $65.00. Sounds like alot but we only use Mogami cable and the best connectors and parts money can buy. Also we do custom work with different configs at customers request. All of our preamps and battery boxes in this price range have High Pass Filers that can be customized for the end user we normally use 80hz we find its right arount the sweet spot for most venues.

Hi Richard I use OPA2227A opamp for my preamp that provides -00 to +20db of gain via a dual alps pot. In a very cute little package about the size of pack of cigarettes. In the preamp we use nothing but 1% resistors Metal film and we also use epoxy to coat our circuit so no one steals it . You know it’s hard to keep others from taking your ideas and selling them for profit. We have worked hard to get this preamp to have a very low distortion very low distortion of 0.002% this preamp does not have a clip light I think they are lame. They tell you when the preamp is distorting but give you no reference as to when the recorder is distorting. We feel that it’s more important to watch the recorder then our little box. As far as the mod we do to our mics and anyone else's mics that’s top secret ask Audio Technica what they do to the capsules they purchase to mod them. I doubt you would get an answer. This is not bullshit my mod works and works well and it’s not the Linkwitz mod that everyone does but in order for this to work it has to be a three wire capsule or at least one that I can make three wire. We use nothing but the best parts all of our products are hand built and made to last.

Chris Church

Hey, thanks for the information.

So, you've got two miniXLR connectors on your box, right?  Does that mean I can plug standard AT mics in there?  (Ie., + on pin 3, audio on pin 2, and shield on pin 1)  If so, I (and several others here) would be interested in quotes for: 1) battery box alone (ie., 3-wire battery box), 2) box with OPA opamp (and 3-wire power).  Please post those two prices here.

Thanks,
  Richard

[poorlyconditioned]

Prices for just a battery box with mini XLR connectors is $100.00 + shipping. The preamp version with 00-to+20 db with adjustable gain control is $225.00 + shipping, if you want us to put some ends on your mics and do our mod its $50 extra. The mics must be three wire we can also do three wire to two wire adaptors with our mod built in for $65.00. Sounds like alot but we only use Mogami cable and the best connectors and parts money can buy. Also we do custom work with different configs at customers request. All of our preamps and battery boxes in this price range have High Pass Filers that can be customized for the end user we normally use 80hz we find its right arount the sweet spot for most venues.

Hi Richard I use OPA2227A opamp for my preamp that provides -00 to +20db of gain via a dual alps pot. In a very cute little package about the size of pack of cigarettes. In the preamp we use nothing but 1% resistors Metal film and we also use epoxy to coat our circuit so no one steals it . You know it’s hard to keep others from taking your ideas and selling them for profit. We have worked hard to get this preamp to have a very low distortion very low distortion of 0.002% this preamp does not have a clip light I think they are lame. They tell you when the preamp is distorting but give you no reference as to when the recorder is distorting. We feel that it’s more important to watch the recorder then our little box. As far as the mod we do to our mics and anyone else's mics that’s top secret ask Audio Technica what they do to the capsules they purchase to mod them. I doubt you would get an answer. This is not bullshit my mod works and works well and it’s not the Linkwitz mod that everyone does but in order for this to work it has to be a three wire capsule or at least one that I can make three wire. We use nothing but the best parts all of our products are hand built and made to last.

Chris Church

Hey, thanks for the information.

So, you've got two miniXLR connectors on your box, right?  Does that mean I can plug standard AT mics in there?  (Ie., + on pin 3, audio on pin 2, and shield on pin 1)  If so, I (and several others here) would be interested in quotes for: 1) battery box alone (ie., 3-wire battery box), 2) box with OPA opamp (and 3-wire power).  Please post those two prices here.

Thanks,
  Richard

Thanks +T Chris!

  Richard

[willndmb]

thanks for the info

[CHURCH-AUDIO]

Hi remember differnt signal path = differnent sound. In order to do a subjective test you would have to use the same adaptor for both mics thus making the comparrisons MOOT. If you take the output of the mic and connect it from the XLR and just run a phantom supply into our sound analyizer then run the same test with the mic capsule connected to a simple battery box the sound is the same both with an analyzer and with my 20 years of using my ears for a living. You can not say they sound differnt unless you can duplicate the SAME SIGNAL PATH FOR BOTH PHANTOM AND DIRECT BATTERY CONNECTION with the method we have just laid out.

Remember when you use the phantom method you are going to be using an XLR input 150 to 600 ohm when you use the battery box method your terminating to a line input 10k nominal impedence. How can you compair the two? its not a fair test.

The more you load a condenser mic down the more you decrease its high end response these mics are 1kohm Capsules so the only thing that little Phantom adaptor does is A- Provide a bias supply for the said capsule B-reduce the mics output by putting the signal thru a buffer amp C- act as a impedence converter and last but not least D - Create a diferentially balanced output ASK audio Technica they will tell you the same thing I just did.

THERE IS NO CHANGE IN RESPONSE between the two except the XLR adaptor method has a built in HIGH PASS FILTER why?
Because this mic was never designed as a recording mic it was a LAV and a inst mic.

There is a differnce in SPL because the buffer circuit reduces the sensitivity of the mic capsule it has to because mic input is -50 line input is -20 to +4 dB if they boosted the signal in the Phantom adaptor they would overload the mic input on any preamp that did not have a pad.


thus the increased SPL of the mic by using the Phantom method is not actually a real performance increase so much as it is just a pad on the mic capsule that reduces its sensitivity. Thus it can handle high SPL but at a reduced output this is not a problem if your using a good mic pre but it sure is if your not. That is why I feel that using a preamp with out the Phantom adaptor is best because you dont end up reducing the output of the capsule that much thus you end up with a better signal to noise ratio and aint that worth it?
the only reason why you guys that use mic preamps via XLR dont notice the noise is your recording loud source compair the noise floor of the two methods the phantom adaptor and the battery supply / a good unbalanced mic pre and we will see who's signal to noise ratio is better.


Chris Church

In sound quality, there is a night and day difference between non-phantom power at853's and phantom powered at853's.  It's like removing a veil off of them (i'm talking about cardioids).  Bass is punchy, highs sparkle...total different beast compared to at853's>sp bbox which sounded muffled and rolled off highs. 

[CHURCH-AUDIO]

Another reason is you can not just connect a pair of mics into a line input and call it a day. Because of the loading issue i talked about before you need to have a preamp that does not load down the mics and thus lose the fidelity.
Thats why some mics have transformers in them. Some recording consoles have transformers because they do not load down a mic in the same way as a opamp. The more resistance you pile up on that poor little capsule the less it feels like really producing good highs and lows. So we have a preamp that does not load the crap out of a capsule thus produces a good sound funny how that works.

Chris Church

In sound quality, there is a night and day difference between non-phantom power at853's and phantom powered at853's.  It's like removing a veil off of them (i'm talking about cardioids).  Bass is punchy, highs sparkle...total different beast compared to at853's>sp bbox which sounded muffled and rolled off highs. 

[kuba]

Well, thanks CHURCH-AUDIO for information. However, I'm still a bit lost in technical english.

If I understand, then:
a) 3-wire battery should give the same sound as phantom powering (speaking about AT853) - not considering higher output impedance (which should be not as much of an issue with iRiver H120 and it's low input impedance)

b) AT853 capsule is capable of 12V powering, If I replaced 9V in 3-wire box with 12V, I would get even better results.

c) What about AT831 and 3-wire box? Is it worth the labour?

Yes? No? Correct me if I'm wrong.
Thanks