Topic: AT-853's>UA5 question

[run_run_run]

The only conceivable advantage I can see is that in using a phantom adaptor you would probably have to have the mics wired in the 3-wire configuration which allows for more headroom. But 3-wire directly from a 9v supply would yield precisely the same results*.

*except for the added sonic signature of the preamp if such a device is being used.

Slightly odd comment there; I wasn't suggesting that a preamp would necessarily be in the chain... but that does remind me: I'm pretty sure that the AT phantom adaptors have a HPF built in. Not sure if the same goes for the Samson etc ones but I certainly wouldn't want to be running cards with an undefeatable bass cut.

on my 915s you can shut off the bass cut

[yousef]

on my 915s you can shut off the bass cut

I stand corrected. Does this go for the phantom adaptors that come "built-in" to the AT853s? The last time I was looking at picking up some of these (a couple of years ago at least) it didn't seem to be switchable.

[ashevillain]

The AT adapters have a switchable HPF (at least the ones I used have did...there are a couple different versions). The Samson adapters don't have HPF at all.

My comment wasn't intended to be odd...just that if you are using a preamp to supply the phantom power (which the previous poster is) obviously there are some sonic characteristics involved. I doubt that he is running them directly into a MixPre as well.

[nameloc01]

i have a minty set of AT8532s..if anyone is interested in buying them:

http://taperssection.com/index.php?topic=133096.0

(the benefit of running the AT mics with xlrs and adaptors is obviously the locking connectors,the highest SPL handling level with no compromise on the noise floor or gain loss and the ability to run them straight from a board or a preamp supplying power,which is what they were designed for)

[sunjan]

on my 915s you can shut off the bass cut

I stand corrected. Does this go for the phantom adaptors that come "built-in" to the AT853s? The last time I was looking at picking up some of these (a couple of years ago at least) it didn't seem to be switchable.

Yep, the AT853Rx comes with hardwired AT8533 adapters, which feature the switch. Although it's very tiny and hardly visible if you're not looking for it. You might need a pencil to move it, or sharp nails :-)

I get your point that P48 is not ideal from a power management point of view. But since most of us are using a DVD battery to power the UA5 in the field anyway, the juice provided is more than necessary to supply phantom power as well.

Being able to eliminate the additional bbox from the chain means less things that can go wrong, and less things to charge/check before the gig. Once the adapters lock in place and the phantom LED on the UA-5 lights up, they are 100% foolproof.

I also believe there is some truth in what nameloc01 said about SPL handling being better when powering them with P48. I recall reading it here when I shopped for my AT853Rx long ago...

[yousef]

I can understand the simplicity of plugging the mics through the adaptors directly into one box that can provide power and gain (although when I used Samson adaptors I found them horribly ungainly and constantly worried about the leverage effect on my pre's connectors).

But I'm not sure why this myth persists about the mics' performance when using phantom supplies - the adaptors step it down to 9v (or possibly significantly less than this based on illconditioned's investigations, if memory serves), effectively making the power output from the adaptors and the output from a 3-wire battery box exactly the same.

The only real sonic benefit I can see from using the adaptors is that they provide a balanced output but for the cable lengths we use I suspect that this effect would be negligible.

[nameloc01]

i dont think its a myth about phantom vs. a simple 3-wire BB, its a myth that any type of 2-wire setup (modded or un-modded) will perform the *exact same* as a 3-wire or phantom setup..because it wont.

just get some adaptors and run the mics off of your UA5.
(or you can be really slick and buy my 8532s  ;P )

[moooose]

mumble mumble....
I always connect my 853 directly to a phantom power source (in my case a SD MixPre). They never fried and deliver good results indeed.

I don't think I quite believe you...

How are your 853s terminated? I'd be willing to bet that they have great big phantom adaptors on the end of them that step the p48 down to 9v.

No problem if you don't believe me and if you're willing to bet. Just swing by (Siena, Italy) and we'll discuss this issue live - anyway you will pay the bottle of Brunello di Montalcino. 

The mics are plain SP CMC 4U, terminated with the original 3.5mm stereo minijack. No AT adapters or whatever.
When I considered the possibility of connecting them to the MixPre I searched extensively the web and found out that they could actually be phantom powered. I built a simple stereo mini jack > 2 xlr adapter and tried, although with a slight thrill. Everything worked fine (the MP's phantom voltage selector is on the 48v position...) and I'm quite satisfied with this solution. 

That's it.

[yousef]

The mics are plain SP CMC 4U, terminated with the original 3.5mm stereo minijack. No AT adapters or whatever.
When I considered the possibility of connecting them to the MixPre I searched extensively the web and found out that they could actually be phantom powered. I built a simple stereo mini jack > 2 xlr adapter and tried, although with a slight thrill. Everything worked fine (the MP's phantom voltage selector is on the 48v position...) and I'm quite satisfied with this solution. 

That's it.

Well, then... This is entirely new to me and, as far as I'm aware, to the "phantom and AT853s" debate which seems to come up on TS.com every couple of years...

I'd be interested to know the wiring details of how the minijack is connected to the XLRs.

But if you are delivering 48v to the capsules, it begs the question why does AT attach the step-down power modules to the mics in the first place?

The plot thickens...

[run_run_run]

The mics are plain SP CMC 4U, terminated with the original 3.5mm stereo minijack. No AT adapters or whatever.
When I considered the possibility of connecting them to the MixPre I searched extensively the web and found out that they could actually be phantom powered. I built a simple stereo mini jack > 2 xlr adapter and tried, although with a slight thrill. Everything worked fine (the MP's phantom voltage selector is on the 48v position...) and I'm quite satisfied with this solution. 

That's it.

Well, then... This is entirely new to me and, as far as I'm aware, to the "phantom and AT853s" debate which seems to come up on TS.com every couple of years...

I'd be interested to know the wiring details of how the minijack is connected to the XLRs.

But if you are delivering 48v to the capsules, it begs the question why does AT attach the step-down power modules to the mics in the first place?

The plot thickens...

AFAIK the caps do NOT get a full 48 volts

[nameloc01]

48v straight to the capsules would fry them,period. The mics are manufactued by AT with a mini xlr on each and 25' cables, designed to run off of their AT power modules or off of a board/pre that supplies phantom power in conjunction with an adaptor, these mics are designed really as "hanging choir mics". The only reason that the 853s were/are terminated into a single mini plug is because Sound Pros was/is selling them like this to offer a cheaper setup to the public, by cheaper i mean mics terminated together and ran from one of their "El Cheapo" 2 wire battery boxes instead of selling them separated with mini xlrs and ran from a phantom box (such as a $150-$200 PS2),with the AT/Nady/Samson adaptors ( the adaptors step down the voltage from 48v to a usable 9-12)..SP now sees this issue after all of the problems with people getting clipped recordings and has like 3 or 4 ordering options when you buy these mics now,but only one is correct..obviously the options vary in $$...again,it comes down to the almighty dollar and how much you want to spend.
There is a difference of several hundred dollars (between the single termination and a simple 2 wireBB vs. the same mics with mini xlrs,adaptors and a 3 wire box (PS2 or pre) to run them), and when people are told they will "perform the same way as 3 wire/phantom" you cant blame people for buying them, its a much cheaper option. But the truth of the situation is that this is the incorrect way to run them, they do not get adequate power and will clip in moderate to high SPL situations, this is the reason certain people came up with the "4.7k" mod, to compensate for the fact that the mics were being ran incorrectly to begin with.
Its not really a complicated situtation, 3 wire mics should be ran 3 wire..simple as that.
The reason for the ongoing debate is that people were trying to take inexpensive shortcuts initially and are constantly spreading mis-information,to their benefit,..of course. And that when it is said that the 853s are being "modded" (or modded for  high spl, by "adding mini xlrs and adaptors"), its not really "modding" them, its simply restoring them to the way they were made by AT, the real "mod" is running them 2wire (incorrect) the way there are sometimes sold.

im not trying to knock anyone, im just stating the facts.

[sunjan]

mumble mumble....
I always connect my 853 directly to a phantom power source (in my case a SD MixPre). They never fried and deliver good results indeed.

I don't think I quite believe you...

How are your 853s terminated?

The mics are plain SP CMC 4U, terminated with the original 3.5mm stereo minijack. No AT adapters or whatever.
When I considered the possibility of connecting them to the MixPre I searched extensively the web and found out that they could actually be phantom powered. I built a simple stereo mini jack > 2 xlr adapter and tried, although with a slight thrill. Everything worked fine (the MP's phantom voltage selector is on the 48v position...)

OK, here's the clue. The mics are not connected directly to P48, since there is an adapter inbetween.

Each XLR has three pins. But since you only have a shared TRS at the other end, most likely the pin carrying the power is not properly connected to the TRS end - the P48 current goes to the shield/ground instead. Basically, what you're getting from the mics is the unbalanced signal over 2-wire.

Measure the resistance between the contact on each side of the adapter for the proof, and measure the voltage over the TRS while the adapter is connected to the pre.

Like nameloc said, if you fed P48 directly to your 853s, they would have been fried.

[moooose]

OK, here's the clue. The mics are not connected directly to P48, since there is an adapter inbetween.

Each XLR has three pins. But since you only have a shared TRS at the other end, most likely the pin carrying the power is not properly connected to the TRS end - the P48 current goes to the shield/ground instead. Basically, what you're getting from the mics is the unbalanced signal over 2-wire.

Measure the resistance between the contact on each side of the adapter for the proof, and measure the voltage over the TRS while the adapter is connected to the pre.

Like nameloc said, if you fed P48 directly to your 853s, they would have been fried.

IMHO what you and nameloc01 say explains the whole story. In other words, it depends on wiring. Since I don't tape anything loud I never had any clipping problem and I enjoyed this solution because in my case it works fine.

Now I'd like to try the AT phantom adapters. A couple of months ago I purchased a pair of them from a TS member but they got lost and never arrived in my mailbox.
Anyone has a pair of AT 8533x in a closet? 


Anyway, this forum and your competence are amazing. Thank you.