3wire batt bocx for AT943

[Zaphod]

So what exactly is the benefit of running a three wire battery box, instead of a standard Soundpro type battery box?

Higher SPL

Gotcha should've figured that, +T

[audBall]

So what exactly is the benefit of running a three wire battery box, instead of a standard Soundpro type battery box?

Higher SPL

Gotcha should've figured that, +T

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

[graemecogger]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

[audBall]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

Yep, I was definitely mixed up....thanks for the clarification.

Your explanation leads me to another question.  (see pic here: http://www.soundprofessionals.com/mas_assets/full/SP-PHANTOM.jpg)
If the SP phantom mod still uses 1/8" plugs to terminate the mics, and then uses the female 1/8 > miniXLR cable, is it rendering a 3wire setup useless and, basically, bringing it back to a 2wire setup?  Does that make sense?

[Sanjay]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

Yep, I was definitely mixed up....thanks for the clarification.

Your explanation leads me to another question.  (see pic here: http://www.soundprofessionals.com/mas_assets/full/SP-PHANTOM.jpg)
If the SP phantom mod still uses 1/8" plugs to terminate the mics, and then uses the female 1/8 > miniXLR cable, is it rendering a 3wire setup useless and, basically, bringing it back to a 2wire setup?  Does that make sense?

No, because if its a 1/8" stereo cable, there is still three different sections on it, power, signal and ground.  By using a stereo cable for each mic, it still maintains its three wire capabilities. 

Essentially to break it down, the 3 wire battery box maintains a seperate ground for each mic, wheras the sp battery box keeps a shared ground and shared power.   

[audBall]

word, thanks Sanjay!

[poorlyconditioned]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

Yep, I was definitely mixed up....thanks for the clarification.

Your explanation leads me to another question.  (see pic here: http://www.soundprofessionals.com/mas_assets/full/SP-PHANTOM.jpg)
If the SP phantom mod still uses 1/8" plugs to terminate the mics, and then uses the female 1/8 > miniXLR cable, is it rendering a 3wire setup useless and, basically, bringing it back to a 2wire setup?  Does that make sense?

No, because if its a 1/8" stereo cable, there is still three different sections on it, power, signal and ground.  By using a stereo cable for each mic, it still maintains its three wire capabilities. 

Essentially to break it down, the 3 wire battery box maintains a seperate ground for each mic, wheras the sp battery box keeps a shared ground and shared power.   

I agree with Sanjay here.

I would try to avoid those 1/8" plugs, though.  Just put miniXLR plugs on the mics and be done with it.  Then you can either: 1) use the three wire batt. box with miniXLR sockets on it, or 2) use Samson or other adapters with miniXLR jacks on them.  Standardize to miniXLR plugs on everything.  That is what I did, so all my AT853 and AKG CK91, 93 caps.

  Richard

[Sanjay]

def use the mini xlr's, my gear has gone flying off me during stealthing when a mosh pit started and if it wasn't for those locking connectors i would have been picking up shit all over.

[audBall]

I definitely hear what you guys are saying.  My current setup with the AT's is like the picture I showed (hence the posted picture and my recent questions). I always preferred the miniXLRs and wished that my bbox used them as well.   It'll be just my luck when those extra cables in the chain go kerplunk on me.  Soldering miniXLRs looks fun   

[whatboutbob]

So I just got done building the 3 wire battery box for which Graeme was kind enough to provide the schematic above, and have replaced my sp-cmc-10's 1/8' jack with 2 mini-xlrs.  I'm pleased to report nothing's exploded...yet...

Looks like its about 6dB quieter than running into the sp box (sp-sb6).  I'm yet to test in anger, so I'm not sure if the spl handling has improved just yet.  First run will be in a couple of nights, though the best upcoming test for it should be Dinosaur Jr in about 3 weeks.  Wish me luck.

Btw, if I can build this, just about any muppet can.

[poorlyconditioned]

So I just got done building the 3 wire battery box for which Graeme was kind enough to provide the schematic above, and have replaced my sp-cmc-10's 1/8' jack with 2 mini-xlrs.  I'm pleased to report nothing's exploded...yet...

Looks like its about 6dB quieter than running into the sp box (sp-sb6).  I'm yet to test in anger, so I'm not sure if the spl handling has improved just yet.  First run will be in a couple of nights, though the best upcoming test for it should be Dinosaur Jr in about 3 weeks.  Wish me luck.

Btw, if I can build this, just about any muppet can.

+T to Adam.  I almost sold him a battery box, but due to me having a bad day and Adam's persistence, he has built his own.  I encourage anyone to do this, using either Graeme's or my circuits.  You'll feel like a hotter and stronger geek when you do

  Richard

[whatboutbob]

...and a +T back Richard...thanks for all your patience with all my newbie solder-geek q's.

[jeromejello]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

  i am an unfrozen caveman layer and your words and discriptions sometimes frighten me...  however, when i contacted chris at sp when i had a similar idea about only half the power going to the mics.  i told him that i would rather 2 9v in the box so the mics could each have the full 9v or to have a larger cell put in (12v) if it was going to be split.  he told me that the mics would still be recieving 9v each even with one battery.  now i dont know if what he said and you describe in a technical way means the same, but at the end of the day, he had my specific request and an unlimited budget to achieve that and only used one battery.

[poorlyconditioned]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

  i am an unfrozen caveman layer and your words and discriptions sometimes frighten me...  however, when i contacted chris at sp when i had a similar idea about only half the power going to the mics.  i told him that i would rather 2 9v in the box so the mics could each have the full 9v or to have a larger cell put in (12v) if it was going to be split.  he told me that the mics would still be recieving 9v each even with one battery.  now i dont know if what he said and you describe in a technical way means the same, but at the end of the day, he had my specific request and an unlimited budget to achieve that and only used one battery.

I think Chris did the correct wiring for a 3-wire battery box.  If you get a chance, I'd be interested in seeing a close up photo of the guts, perhaps with board/battery holder removed.

If in fact Chris has wired it correctly, we could just instruct others to ask Chris for your "special order" box.  Or, we could just give Sanjay a ring...

  Richard

[audBall]

Technically speaking (not my native tongue  ), the sound pros box (12v batt box excluded) only provides ~4.5volts to each mic with the 9v battery.  The 3wire setups provide a full 9v to each mic, correct?  At least, that's how I understood it...    (as always, someone chime in if need be)

I suspect that you're a little mixed up about how the battery boxes work
The goal is to have roughly half the supply voltage across the FET in the mic, for best overload levels.
With a 2-wire connection you should end up with the FET drain (output wire) at about 4.5V and the FET source at 0V (it's connected to the ground wire) - that gives 4.5V across the FET.
With a 3-wire connection, the FET drain (red wire) is at 9V and the FET source (yellow wire) is at about 4.5V - again that's 4.5V across the FET.
Of course it's possible that the Sound Professionals box does something weird, but it seems unlikely.
HTH

  i am an unfrozen caveman layer and your words and discriptions sometimes frighten me...  however, when i contacted chris at sp when i had a similar idea about only half the power going to the mics.  i told him that i would rather 2 9v in the box so the mics could each have the full 9v or to have a larger cell put in (12v) if it was going to be split.  he told me that the mics would still be recieving 9v each even with one battery.  now i dont know if what he said and you describe in a technical way means the same, but at the end of the day, he had my specific request and an unlimited budget to achieve that and only used one battery.

As much as I would like that to be the truth, if it were, then people would be frying their DPAs left and right, right?