Topic: Simple hack to increase SPL on AT853

[poorlyconditioned]

I finally did a simple (and obvious) hack on AT853's to prevent overloading.

Normally they are connected like this:
- red wire: + battery box, and audio
- yellow wire and shield: ground for battery and audio
The standard (two-wire) battery box supplies power to the mics through a 10k resistor.

What I did was put a 4.7k resistor between yellow and ground.  (Actually, I put a *tiny* surface mount part right at the capsule, but you could do this anywhere on the cable.)  Now I power the mics with the standard (two-wire) battery box.  This will reduce gain a bit, but it *should* prevent overloading.

I think this idea originates with Dick Campbell, where he used it for WM60A mics for speaker response measurement.

Anyway, I modified a pair of my mics and sold them to Bobcat.  He's going to torture test them at some Tool shows...

  Richard

[Church-Audio]

Thats actually my mod but its ok you do not have to give me credit
I have measured the distortion before and after the before 8% at 114db @1k after 0.5% at 114db @1k net loss of output 5.6 dB
Chris Church
ps....

Dick Might have come up with it at the same time as me,  But I have been doing that mod for 10 years now. I have just recently done it to the 3 wire in the last 2 years It does work great.

And do not use a surface mount use a 1/8th watt resistor via NTE you have to order them they are metal film 2% I have to hand match them all because if you deviate from the 4.7k by as much as 100 ohms your distortion goes right up again.

I finally did a simple (and obvious) hack on AT853's to prevent overloading.

Normally they are connected like this:
- red wire: + battery box, and audio
- yellow wire and shield: ground for battery and audio
The standard (two-wire) battery box supplies power to the mics through a 10k resistor.

What I did was put a 4.7k resistor between yellow and ground.  (Actually, I put a *tiny* surface mount part right at the capsule, but you could do this anywhere on the cable.)  Now I power the mics with the standard (two-wire) battery box.  This will reduce gain a bit, but it *should* prevent overloading.

I think this idea originates with Dick Campbell, where he used it for WM60A mics for speaker response measurement.

Anyway, I modified a pair of my mics and sold them to Bobcat.  He's going to torture test them at some Tool shows...

  Richard

[poorlyconditioned]

Thats actually my mod but its ok you do not have to give me credit
I have measured the distortion before and after the before 8% at 114db @1k after 0.5% at 114db @1k net loss of output 5.6 dB
Chris Church
ps....

Dick Might have come up with it at the same time as me,  But I have been doing that mod for 10 years now. I have just recently done it to the 3 wire in the last 2 years It does work great.

And do not use a surface mouu have to order them they are metal film 2% I have to hand match them all because if you deviate from the 4.7k by as much as nt use a 1/8th watt resistor via NTE yo100 ohms your distortion goes right up again.

I finally did a simple (and obvious) hack on AT853's to prevent overloading.

Normally they are connected like this:
- red wire: + battery box, and audio
- yellow wire and shield: ground for battery and audio
The standard (two-wire) battery box supplies power to the mics through a 10k resistor.

What I did was put a 4.7k resistor between yellow and ground.  (Actually, I put a *tiny* surface mount part right at the capsule, but you could do this anywhere on the cable.)  Now I power the mics with the standard (two-wire) battery box.  This will reduce gain a bit, but it *should* prevent overloading.

I think this idea originates with Dick Campbell, where he used it for WM60A mics for speaker response measurement.

Anyway, I modified a pair of my mics and sold them to Bobcat.  He's going to torture test them at some Tool shows...

  Richard

Cool.  I thought that might be what you were doing, but I didn't want to make any claims or disclose any of your proprietary methods.

I'm still going to use three wire for my own stuff.  One thing is I love those locking miniXLR connectors (instead of the unreliable stereo 1/8" miniplugs).  Another thing is with 3-wire, you can get "all" the voltage, instead of losing 1/2 or 1/3 of it on that 5k resistor.  All of my stuff (AKG CK91/2/3, AT853, Naks, etc) use the same three-wire configuration.

  Richard

[Church-Audio]

Electronics is like music there are no proprietary methods/ideas anymore just good ideas that we all come up with sooner or later I guess I will refund the shipping on the mics since you already know one of my little secrets. And I don't feel like having them all exposed.

Chris Church

Thats actually my mod but its ok you do not have to give me credit
I have measured the distortion before and after the before 8% at 114db @1k after 0.5% at 114db @1k net loss of output 5.6 dB
Chris Church
ps....

Dick Might have come up with it at the same time as me,  But I have been doing that mod for 10 years now. I have just recently done it to the 3 wire in the last 2 years It does work great.

And do not use a surface mouu have to order them they are metal film 2% I have to hand match them all because if you deviate from the 4.7k by as much as nt use a 1/8th watt resistor via NTE yo100 ohms your distortion goes right up again.

I finally did a simple (and obvious) hack on AT853's to prevent overloading.

Normally they are connected like this:
- red wire: + battery box, and audio
- yellow wire and shield: ground for battery and audio
The standard (two-wire) battery box supplies power to the mics through a 10k resistor.

What I did was put a 4.7k resistor between yellow and ground.  (Actually, I put a *tiny* surface mount part right at the capsule, but you could do this anywhere on the cable.)  Now I power the mics with the standard (two-wire) battery box.  This will reduce gain a bit, but it *should* prevent overloading.

I think this idea originates with Dick Campbell, where he used it for WM60A mics for speaker response measurement.

Anyway, I modified a pair of my mics and sold them to Bobcat.  He's going to torture test them at some Tool shows...

  Richard

Cool.  I thought that might be what you were doing, but I didn't want to make any claims or disclose any of your proprietary methods.

I'm still going to use three wire for my own stuff.  One thing is I love those locking miniXLR connectors (instead of the unreliable stereo 1/8" miniplugs).  Another thing is with 3-wire, you can get "all" the voltage, instead of losing 1/2 or 1/3 of it on that 5k resistor.  All of my stuff (AKG CK91/2/3, AT853, Naks, etc) use the same three-wire configuration.

  Richard

[poorlyconditioned]

Electronics is like music there are no proprietary methods/ideas anymore just good ideas that we all come up with sooner or later I guess I will refund the shipping on the mics since you already know one of my little secrets. And I don't feel like having them all exposed.

Chris Church

Thats actually my mod but its ok you do not have to give me credit
I have measured the distortion before and after the before 8% at 114db @1k after 0.5% at 114db @1k net loss of output 5.6 dB
Chris Church
ps....

Dick Might have come up with it at the same time as me,  But I have been doing that mod for 10 years now. I have just recently done it to the 3 wire in the last 2 years It does work great.

And do not use a surface mouu have to order them they are metal film 2% I have to hand match them all because if you deviate from the 4.7k by as much as nt use a 1/8th watt resistor via NTE yo100 ohms your distortion goes right up again.

I finally did a simple (and obvious) hack on AT853's to prevent overloading.

Normally they are connected like this:
- red wire: + battery box, and audio
- yellow wire and shield: ground for battery and audio
The standard (two-wire) battery box supplies power to the mics through a 10k resistor.

What I did was put a 4.7k resistor between yellow and ground.  (Actually, I put a *tiny* surface mount part right at the capsule, but you could do this anywhere on the cable.)  Now I power the mics with the standard (two-wire) battery box.  This will reduce gain a bit, but it *should* prevent overloading.

I think this idea originates with Dick Campbell, where he used it for WM60A mics for speaker response measurement.

Anyway, I modified a pair of my mics and sold them to Bobcat.  He's going to torture test them at some Tool shows...

  Richard

Cool.  I thought that might be what you were doing, but I didn't want to make any claims or disclose any of your proprietary methods.

I'm still going to use three wire for my own stuff.  One thing is I love those locking miniXLR connectors (instead of the unreliable stereo 1/8" miniplugs).  Another thing is with 3-wire, you can get "all" the voltage, instead of losing 1/2 or 1/3 of it on that 5k resistor.  All of my stuff (AKG CK91/2/3, AT853, Naks, etc) use the same three-wire configuration.

  Richard

Hey Chris,

I wouldn't worry about people finding out this stuff.  Unlike others who rely on secret methods (eg., Core-audio) we are paying you for honest disclosure of your product, quality work, and great prices.  It is not like one of us is going to start buying hundreds of capsules or opamps and start competing with you.

You've already told us what is inside your some of your gear (preamps, etc).  Hell, if somone wants to really bust you, they will buy your stuff under an assumed name, take it apart, and try to copy it.  No way you're going to prevent that.

Oh yeah, the other thing is most other competitors are incompetant as well, so they couldn't even do this handiwork, even if they wanted to.

So, please send me your stuff.  I'm not out to bust your methods or sources.  I'm just out to give them a fair shake.  My *guess* at this point is that they will sound close to, but not quite as good as the AT853.  I'd like to try them out though.  Well, if I don't someone else will.  I think you've got a good product at $100 or whatever.  Aside from a few used pairs of AT853 I'm selling, new pairs are going to cost $200 at Soundpros.  Oh yeah, I've sold just three pairs *total* of AT853 over the last year.  I think I'll sell one more and that will probably be it.

  Richard

[poorlyconditioned]

Dear Chris:

Hmm.  OK, maybe don't bother sending me those mics after all.  Just refund the shipping.

I wanted to compare to AT853, but someone else can do that with the "loaner" pair.

I also don't want to be blamed for disclosing anything more about them...

Well, I guess my opinion is that things should be open, and you will make more sales in the long run just based on the workmanship and service.  But I don't want to start an argument about that.  I just want to keep tweaking gear and recording.

  Richard

[Church-Audio]

Hey relax I am sending you the mics I would value your opinion I think your very talented with electronics design I have seen some of your handy work you just have to get better with a dremel tool but hell when I started hacking things together well lets just say I am glad that I have not seen any for sale I would be too embarrassed to say I made them. I have sold over 2000 preamps world wide after about 100 you get pretty good at putting them together lol. I would like to chat with you about preamp design some day I have a few challenges in the next few weeks and it would be nice to bounce some ideas off you. I am sorry for my first post it was immature and brash. I was upset about one of my mods being exposed but you know what who cares. People will figure things out on there own sooner or later like I said about music with electronics its all been done before. Just a different package same result.

Chris Church

Dear Chris:

Hmm.  OK, maybe don't bother sending me those mics after all.  Just refund the shipping.

I wanted to compare to AT853, but someone else can do that with the "loaner" pair.

I also don't want to be blamed for disclosing anything more about them...

Well, I guess my opinion is that things should be open, and you will make more sales in the long run just based on the workmanship and service.  But I don't want to start an argument about that.  I just want to keep tweaking gear and recording.

  Richard

[Church-Audio]

T+ for figuring out the 4.7k thing with out a distortion analyser ( I have one so it makes it easy)

Dear Chris:

Hmm.  OK, maybe don't bother sending me those mics after all.  Just refund the shipping.

I wanted to compare to AT853, but someone else can do that with the "loaner" pair.

I also don't want to be blamed for disclosing anything more about them...

Well, I guess my opinion is that things should be open, and you will make more sales in the long run just based on the workmanship and service.  But I don't want to start an argument about that.  I just want to keep tweaking gear and recording.

  Richard

[Patrick]

I was upset about one of my mods being exposed but you know what who cares. People will figure things out on there own sooner or later like I said about music with electronics its all been done before. Just a different package same result.

Chris, not to sound like a dick, but you are the one who exposed the mod.  While Richard put it out for all to see, you came along and claimed that it was yours.  You could have just not said anything, and you would still have a secret.

[Church-Audio]

Pat it’s not the only mod I do, so it’s all cool I don’t mind me and Richard talked about It I apologized and its over
Chris Church

I was upset about one of my mods being exposed but you know what who cares. People will figure things out on there own sooner or later like I said about music with electronics its all been done before. Just a different package same result.

Chris, not to sound like a dick, but you are the one who exposed the mod.  While Richard put it out for all to see, you came along and claimed that it was yours.  You could have just not said anything, and you would still have a secret.

[RebelRebel]

I was upset about one of my mods being exposed but you know what who cares. People will figure things out on there own sooner or later like I said about music with electronics its all been done before. Just a different package same result.

Chris, not to sound like a dick

Thats one of the big issues here...people just pile on. Nothing against you Patrick, you were nice about it..but it was Chris and Poorly's discussion..no need for any other folks to jump in. That is the biggest problem with this site. Gang-ups.

[Josephine]

Would the AT933's benefit from a similar modification?
Used them a couple weeks ago and had a huge overload problem . . . they just couldn't handle it.
Recording is distorted in many places. 

[poorlyconditioned]

Would the AT933's benefit from a similar modification?
Used them a couple weeks ago and had a huge overload problem . . . they just couldn't handle it.
Recording is distorted in many places. 

Yep.  They're pretty similar.  AT831 are also very close.

For my stuff I use a (hard-wired) 3-wire battery box.  But if you have an existing battery box and mic set (eg., from Soundprofessionals), then you should be able to do the "4.7k mod".  Let's call it the "Church" mod, since I think no other retailer is doing this.  (Soundpros don't do any mods, while CoreSound does the Linkwitz mod.)

By the way, please don't ask me to do this.  I don't want to get into doing mods for others.  I sell a few mic sets, etc, when I get overloaded, but I don't want to do mods.

Hmm.  Maybe Chris would do this for you (or others?).  It might be a useful service for those with existing mic sets.  On reflection, this is probably nicer than the 3-wire battery box, especially for those that already have a "standard" 2-wire one...

Can you solder?  If so, take apart the miniplug.  You'll probably see yellow wire (*) shorted to ground (shield), and a red wire for each of channels (L: tip, R: ring).  Seperate the yellow wire and insert a 4.7k resistor between yellow and shield, and try it out.  You may not be able to do this inside the connector, but you could probably hack at the cable and do it somehow ().  Remember to use lots of shrinkwrap and hot melt glue

(*) Some AT mics have a white wire instead of yellow.  So they are either shield/yellow/red or shield/white/red.  Also, some mics have a pair of each yellow and red (star quad cable) and others just have a single wire for each.

  Richard

[Josephine]

Would the AT933's benefit from a similar modification?
Used them a couple weeks ago and had a huge overload problem . . . they just couldn't handle it.
Recording is distorted in many places. 

Yep.  They're pretty similar.  AT831 are also very close.

For my stuff I use a (hard-wired) 3-wire battery box.  But if you have an existing battery box and mic set (eg., from Soundprofessionals), then you should be able to do the "4.7k mod".  Let's call it the "Church" mod, since I think no other retailer is doing this.  (Soundpros don't do any mods, while CoreSound does the Linkwitz mod.)

By the way, please don't ask me to do this.  I don't want to get into doing mods for others.  I sell a few mic sets, etc, when I get overloaded, but I don't want to do mods.

Hmm.  Maybe Chris would do this for you (or others?).  It might be a useful service for those with existing mic sets.  On reflection, this is probably nicer than the 3-wire battery box, especially for those that already have a "standard" 2-wire one...

Can you solder?  If so, take apart the miniplug.  You'll probably see yellow wire (*) shorted to ground (shield), and a red wire for each of channels (L: tip, R: ring).  Seperate the yellow wire and insert a 4.7k resistor between yellow and shield, and try it out.  You may not be able to do this inside the connector, but you could probably hack at the cable and do it somehow ().  Remember to use lots of shrinkwrap and hot melt glue

(*) Some AT mics have a white wire instead of yellow.  So they are either shield/yellow/red or shield/white/red.  Also, some mics have a pair of each yellow and red (star quad cable) and others just have a single wire for each.

  Richard

I can totally appreciate your not wanting to get started doing modifications, Richard, I have no issue with that . . . . and I thank you for enlightening me about the possibility of modifying my 933s.  I'd be afraid to plug in a solder gun, let alone use it.  lol  I guess there's a first time for everything, but I'm not about to learn on a set of mics . . . . so maybe Chris can chime in, let me know whether this is a mod that he would consider doing.

These are not my main mics and I'd really be in no particular hurry to get this done.  I just read the thread and thought, "Hmm,   I wonder if that would work with my AT933's?"  Now I know.  Thanks, Richard. 

[Church-Audio]

If you need the small resistors to do this I have 1/8th watt I can send you for free they are metal film and very hard to find in a 2% value the you can also build a battery box 3 wire and do this mod inside the battery box you can have it so it can be switched in and out of the circuit for shows that do not require it sort of like a pad..... Well exactly like a pad for your mics but way before the signal ever gets to your second gain stage. Richard has plans for a good battery box if your interested. Or you can purchase one from me if you dont like to build.


Chris Church

Would the AT933's benefit from a similar modification?
Used them a couple weeks ago and had a huge overload problem . . . they just couldn't handle it.
Recording is distorted in many places. 

[mattb]

Hey, I have AT933s too. If I did this mod, would it affect them when I run Phantom? I usually run phantom (I did the SP un-mod to mine) but on occasion a battery box setup would be nice for low profile work.
Another thought is maybe I could build that 4.7k mod into the adapter I built to go from the mini XLRs to the stereo miniplug for battery box use. Would doing this after it goes from three to two wires work?
Thanks for any suggestions!

[whatboutbob]

Anyone *cough* Richard *cough* know how this mod impacts gain compared to the 3-wire config / standard 2 wire?

Off the top of my head I think the 3-wire was about 12dB lower than the standard 2 wire...?

[poorlyconditioned]

Anyone *cough* Richard *cough* know how this mod impacts gain compared to the 3-wire config / standard 2 wire?

Off the top of my head I think the 3-wire was about 12dB lower than the standard 2 wire...?

The "4.7k tweaked" two-wire version should give same loss as 3-wire version, or maybe even a bit *more* loss than the standard two-wire version.

Why more loss???  Well, you're dropping voltage across that 4.7k resistor, and it is not going to your preamp.  Say you've got a 10k resistor in your battery box and a 4.7k resistor inside the mic capsule, then the total load on the mic capsule is approx. 15k (4.7k+10k), but you're only using the 10k part of that, so you're only using 2/3 of the voltage.  The loss is then approx. 20*log10(2/3) ~= -3.5dB.

Maybe Chris can comment.

  Richard

[Javier Cinakowski]

I expereinced some distortion with my mke2's and I would not be suprised if my AT943's will distort in high SPL situations.  They are both 2-wire.

Should I get someone to do the 4.7k mod or should I consider doing the 3-wire set-up?  With the 3-wire I would need a new preamp and I would also need new extention cables for running on a stand. With the 4.7k mod im not sure it would work with the mke2's.  Im kinda bumbed out. I do not know the best route of action here. 

I guess I could just use my mke40's in high SPL situations and use the AT's and mke2's when the SPL's are lower.  Although, I would like to get rid of the SPL variable when chosing what set of mics to run. 


 

[TideBleach]

what would be better for a loud metal show this mod or the 3 wire battery box for SP-AT853's???

thanks

TideBleach

[poorlyconditioned]

what would be better for a loud metal show this mod or the 3 wire battery box for SP-AT853's???

thanks

TideBleach

As far as I can tell, both are pretty much equivalent.  But you will need *some* mod to handle that .

  Richard

[hyperplane]

I expereinced some distortion with my mke2's and I would not be suprised if my AT943's will distort in high SPL situations.  They are both 2-wire.

Should I get someone to do the 4.7k mod or should I consider doing the 3-wire set-up?  With the 3-wire I would need a new preamp and I would also need new extention cables for running on a stand. With the 4.7k mod im not sure it would work with the mke2's.  Im kinda bumbed out. I do not know the best route of action here. 

I guess I could just use my mke40's in high SPL situations and use the AT's and mke2's when the SPL's are lower.  Although, I would like to get rid of the SPL variable when chosing what set of mics to run. 


 

Windorabug: here's what I'm currently doing. I do tape some shows at a local club that are more of the "acoustic" variety, i.e. even though it's coming through a PA, I just can't get great levels running AT mics > 3wire bbox > iriver/Edirol recorder (R-1/R-09).  So, thanks to Richard's aid, I'm building a dual miniXLR > mini-plug cable; thereby running the mics using 2-wire bbox powering. This will, of course, increase the output level of the mics (better levels for softer music, which wouldn't distort anyway).  This way, I can use the *same* pair of mics for louder, or softer shows...  and, it's much cheaper than buying a 3-wire preamp.

To me, the 3-wire "mod" on the mics (with miniXLR connectors) seems to offer the most variety, i.e. with the 4.7k mod, you're stuck with the lower levels and choosing a preamp if you want to use the mics for lower sound (or amplifying the crap out of the WAV file in post). But with the miniXLR connectors for 3-wire powering, you can still "go back" to 2-wire powering as needed, using one of these cables. Yes, the cables cost a little bit (it's the miniXLR connectors that constitute the bulk of the cost)... but like I said, it offers a variety of options and at a more minimal cost than a preamp.

[TideBleach]

what would be better for a loud metal show this mod or the 3 wire battery box for SP-AT853's???

thanks

TideBleach

As far as I can tell, both are pretty much equivalent.  But you will need *some* mod to handle that .

  Richard

thanks 

[TideBleach]

anyone have pics of this mod? also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

TideBleach

[Javier Cinakowski]

also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

I don't think so.  A fellow PT'r had the idea of making an extention cable with the mod.  That way it could be removed.  From what i understand it doesn't work because each mic ground wire is attached to a common point on the mini plug.  I think to get this to work you have to  do it at the mini-plug, in the mic cable or maybe at each capsule?

[TideBleach]

also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

I don't think so.  A fellow PT'r had the idea of making an extention cable with the mod.  That way it could be removed.  From what i understand it doesn't work because each mic ground wire is attached to a common point on the mini plug.  I think to get this to work you have to  do it at the mini-plug, in the mic cable or maybe at each capsule?

thanks. thats what i was afraid of, but at least i dont have to buy a new battery box now just the mics :  )

[poorlyconditioned]

also would it be possible to do the mod in a battery box that way you can still use the mics in a normal 2 wire battery box without the dB loss?

I don't think so.  A fellow PT'r had the idea of making an extention cable with the mod.  That way it could be removed.  From what i understand it doesn't work because each mic ground wire is attached to a common point on the mini plug.  I think to get this to work you have to  do it at the mini-plug, in the mic cable or maybe at each capsule?

thanks. thats what i was afraid of, but at least i dont have to buy a new battery box now just the mics :  )

I believe you *can* implement the 4.7k mod in the mic cable.  For example, if you have a pair of mics each with three wires (2 wires + shield), you could join them together, insert 4.7k resistors between the yellow and the shield on each mic, then run both reds out (left and right mic) to a miniplug.

  Richard

[MLKLuke]

uhm...sorry for the (maybe) stupid question...but...am I High-SPL safe with a 3_wire BBox or I should still need this kind of mod for louder shows (I never had brickwalling problems with denecke PS2 or 3-wire BBbox I'm using with AT853)?

[Chuck]

So Richard:

You replace the 27k resistor (in your famous black board battery box drawing) with the 4.7k resistor?

Chuck

[poorlyconditioned]

So Richard:

You replace the 27k resistor (in your famous black board battery box drawing) with the 4.7k resistor?

Chuck

You have two choices:

- two-wire configuration: replace my (27k) resistor with 4.7k, and use *standard* battery box.  (This has a 10k resistor in series with 9v).

- three-wire: what I drew previously.  That resistor can be anywhere from 5-30k and it will work.  The ideal value is about 10k for AKG CK9x capsules or 22k for AT853 (my previous value was a bit high).  Anyway, I often use 15k so I can use my boxes with both AKG and AT caps.

  Richard

[Chuck]

So Richard:

You replace the 27k resistor (in your famous black board battery box drawing) with the 4.7k resistor?

Chuck

You have two choices:

- two-wire configuration: replace my (27k) resistor with 4.7k, and use *standard* battery box.  (This has a 10k resistor in series with 9v).

- three-wire: what I drew previously.  That resistor can be anywhere from 5-30k and it will work.  The ideal value is about 10k for AKG CK9x capsules or 22k for AT853 (my previous value was a bit high).  Anyway, I often use 15k so I can use my boxes with both AKG and AT caps.

  Richard

Can you point me to the drawings of either one of these, new ways to wire them up?
In the "AT853 Three Wire Battery Box" drawing, there is no 10k resistor. Just the 27k.

I don't have the other drawing to reference...

[soundpro]

Hello all:

I spoke with an engineer at Audio Technica about the modification in this thread. He confirmed that it would lower sensitivity and increase the SPL capability of the AT853 mics.

He also said that it would lower the S/N ratio as the self noise will remain the same (lower sensitivity and same self noise=worse S/N ratio).

Thought you would all like to know this.

Best Regards,

Chris Carfagno
The Sound Professionals, Inc.
3444 Sylon Blvd.
Hainesport, NJ 08036
USA
www.soundprofessionals.com
Toll Free: 800-213-3021
Phone: 609-267-4400
FAX: 609-267-0054

[poorlyconditioned]

Hello all:

I spoke with an engineer at Audio Technica about the modification in this thread. He confirmed that it would lower sensitivity and increase the SPL capability of the AT853 mics.

He also said that it would lower the S/N ratio as the self noise will remain the same (lower sensitivity and same self noise=worse S/N ratio).

Thought you would all like to know this.

Best Regards,

Chris Carfagno
The Sound Professionals, Inc.
3444 Sylon Blvd.
Hainesport, NJ 08036
USA
www.soundprofessionals.com
Toll Free: 800-213-3021
Phone: 609-267-4400
FAX: 609-267-0054

Thanks for the info.

I'm not sure about the SNR though.  I think it might depend on where the noise is coming from, the FET or the electret element itself.

Hmm.  If it comes from the FET then you might lose some SNR.  Suppose you have a 10k load resistor (standard battery box).  Then adding the 4.7k resistor is like really having a ~15k load, but only "using" 10k of it.  Then you would expect to see a voltage output of (10k/15k) ~= 2/3 compared to the usual "three wire" circuit, with say, a 15k load resistor on the source.  So, the *power* loss is 20*log10(2/3) ~= -3.5dB.  That is what I would expect to lose on both sensitivity and on SNR (compared to the three wire).

Now, if the noise is coming from the Capsule itself, then there should be *no* loss of SNR.  Both the noise and the signal are attenuated by ~3.5dB.

Any other ideas?  Like from someone who knows electronics .

  Richard

[Church-Audio]

I don't know electronics as well as some on this board but, I will say that the increase in signal to noise, from having done this mod for over 10 years to panasonic capsules and the like is almost none  existant. And in a loud rock concert situation where you would need it I dont think you would ever hear the difference. Because the source would be so much louder then any self noise could ever be.

Chris Church

Hello all:

I spoke with an engineer at Audio Technica about the modification in this thread. He confirmed that it would lower sensitivity and increase the SPL capability of the AT853 mics.

He also said that it would lower the S/N ratio as the self noise will remain the same (lower sensitivity and same self noise=worse S/N ratio).

Thought you would all like to know this.

Best Regards,

Chris Carfagno
The Sound Professionals, Inc.
3444 Sylon Blvd.
Hainesport, NJ 08036
USA
www.soundprofessionals.com
Toll Free: 800-213-3021
Phone: 609-267-4400
FAX: 609-267-0054

Thanks for the info.

I'm not sure about the SNR though.  I think it might depend on where the noise is coming from, the FET or the electret element itself.

Hmm.  If it comes from the FET then you might lose some SNR.  Suppose you have a 10k load resistor (standard battery box).  Then adding the 4.7k resistor is like really having a ~15k load, but only "using" 10k of it.  Then you would expect to see a voltage output of (10k/15k) ~= 2/3 compared to the usual "three wire" circuit, with say, a 15k load resistor on the source.  So, the *power* loss is 20*log10(2/3) ~= -3.5dB.  That is what I would expect to lose on both sensitivity and on SNR (compared to the three wire).

Now, if the noise is coming from the Capsule itself, then there should be *no* loss of SNR.  Both the noise and the signal are attenuated by ~3.5dB.

Any other ideas?  Like from someone who knows electronics .

  Richard