Topic: 3 Wire Box vs. SP BB for SP AT853's

[scoper]

My current rig:
AT853 (SP) > SP BB (with Levels and Bass Rolloff) > AD20 > JB3

My understanding of the 3 wire BB advantage is that it increases the SPL that the 853's can handle, by increasing the power fed to the mics. It also results in a net decrease of gain that would feed the AD20 (some say -6db, some say more).

Since my BB has level controls, I usually attenuate the levels there slightly, so as not to overdrive the pre-amp in the AD20. I usually run the AD20 at either the minimum (+17db) setting, or the 9-10 o'clock setting.

Isn't this the same effect? I've never had a situation where the mics have brickwalled, even at a recent Billy Joel show where the sound (especially bass) was painfully loud.

With the current config, I also have the option of feeding the JB3 directly from the BB in louder shows, if I want to go superstealth. The 3 wire box (per Sanjay) necessitates using the mini-xlr inputs. I also lose the level control and the bass rolloff (I never use the rolloff anyway).

How is the 3 wire box an advantage to me?

TIA,

Scott

[poorlyconditioned]

My current rig:
AT853 (SP) > SP BB (with Levels and Bass Rolloff) > AD20 > JB3

My understanding of the 3 wire BB advantage is that it increases the SPL that the 853's can handle, by increasing the power fed to the mics. It also results in a net decrease of gain that would feed the AD20 (some say -6db, some say more).

Since my BB has level controls, I usually attenuate the levels there slightly, so as not to overdrive the pre-amp in the AD20. I usually run the AD20 at either the minimum (+17db) setting, or the 9-10 o'clock setting.

Isn't this the same effect? I've never had a situation where the mics have brickwalled, even at a recent Billy Joel show where the sound (especially bass) was painfully loud.

With the current config, I also have the option of feeding the JB3 directly from the BB in louder shows, if I want to go superstealth. The 3 wire box (per Sanjay) necessitates using the mini-xlr inputs. I also lose the level control and the bass rolloff (I never use the rolloff anyway).

How is the 3 wire box an advantage to me?

TIA,

Scott

You claim that you do not brickwall, but my guess is that you are distorting somewhat even in moderatly loud settings.  You might mitigate that with attenuation and bass rolloff, but the distortion is still there.

There are several places you can distort: at the mics, at the mic input (this is usually called "brickwall"), at the line level, or at the ADC (called "clipping").  All can cause distortion.

You solve "brickwall" by attenuating the mics or running line in instead of mic in.  But mic distortion is still there.  You need "3-wire" power to fix this.  You can acheive 3-wire powering, either with a 3-wire battery box (Sanjay or myself) or using phantom power adapters.

My guess is that once you hear proper mic wiring you will be able to tell the difference.  Those AT853 are really very good sounding mics if they are wired correctly.

Now, maybe your music just isn't loud enough.  Maybe you need to move from Billy Joel to something evil!!!

  Richard

[willndmb]

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

[poorlyconditioned]

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

There is nothing wrong with the regular setup, just that a 3-wire battery box (or phantom power) is an improvement.

Try it and you'll see the differnce...

  Richard

[willndmb]

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

There is nothing wrong with the regular setup, just that a 3-wire battery box (or phantom power) is an improvement.

Try it and you'll see the differnce...

  Richard

would the 3 wire replace the sp box all together or is addition too it?

[poorlyconditioned]

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

There is nothing wrong with the regular setup, just that a 3-wire battery box (or phantom power) is an improvement.

Try it and you'll see the difference...

  Richard

would the 3 wire replace the sp box all together or is addition too it?

Yes, the three wire box would replace the SP box.  You would have:
  mics > 3-wire-box > pre/adc > NJB3
skip the pre/adc if you do line in.

  Richard

PS:  Hmm.  Perhaps Sanjay or I should put one of these in the gear loaner program.  Although you would need miniXLRs on your mics to be able to use it.

PPS: Note that neither Sanjay nor I are trying to fluff these for our own profit.  We are just addressing a need out there.  In fact, I haven't even sold one yet!  (Though I think Hyperplane may be my first customer.)  And if you want to build one, here is a (simplified) version:

[scoper]

PPS: Note that neither Sanjay nor I are trying to fluff these for our own profit.  We are just addressing a need out there.  In fact, I haven't even sold one yet!  (Though I think Hyperplane may be my first customer.)  And if you want to build one, here is a (simplified) version:
[img]http://www.cs.uwaterloo.ca/~mannr/AT853/at853_ckt.jpg[/img

I would never accuse you of "fluffing" for profit. I have emailed Sanjay about it (to find out price, before he posted it), and I'm considering. But I don't do a lot of LOUD shows - many of the shows I go to are amplified acoustic music, which is never a problem - I just want maximum flexibility, and to get the best I can out of my equipment.

Scott

[Zaphod]

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

There is nothing wrong with the regular setup, just that a 3-wire battery box (or phantom power) is an improvement.

Try it and you'll see the differnce...

  Richard

Hey Richard have you done any comps of the AT853s phantom vs. three wire?

[poorlyconditioned]

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

There is nothing wrong with the regular setup, just that a 3-wire battery box (or phantom power) is an improvement.

Try it and you'll see the differnce...

  Richard

Hey Richard have you done any comps of the AT853s phantom vs. three wire?

Sorry, I don't think I have any comparisons.  In true unscientific fashion I modified my first pair of AT mics the day they arrived from SoundProfessionals!

I guess I *should* be able to do a comparison though.  God knows, I've got enought AT gear!

  Richard

[CHURCH-AUDIO]

We have a new mod that we do to these mics that keeps the mics two wire but reduces the real distortion to 0.5% at 1k at 114db PM me if your interested.

Chris Church

My current rig:
AT853 (SP) > SP BB (with Levels and Bass Rolloff) > AD20 > JB3

My understanding of the 3 wire BB advantage is that it increases the SPL that the 853's can handle, by increasing the power fed to the mics. It also results in a net decrease of gain that would feed the AD20 (some say -6db, some say more).

Since my BB has level controls, I usually attenuate the levels there slightly, so as not to overdrive the pre-amp in the AD20. I usually run the AD20 at either the minimum (+17db) setting, or the 9-10 o'clock setting.

Isn't this the same effect? I've never had a situation where the mics have brickwalled, even at a recent Billy Joel show where the sound (especially bass) was painfully loud.

With the current config, I also have the option of feeding the JB3 directly from the BB in louder shows, if I want to go superstealth. The 3 wire box (per Sanjay) necessitates using the mini-xlr inputs. I also lose the level control and the bass rolloff (I never use the rolloff anyway).

How is the 3 wire box an advantage to me?

TIA,

Scott

[scoper]

I've ordered the 3 wire box from Sanjay, and he's also making a reverse connection for me (minxlr to 1/8") so I can use the mics with my old SP battery box (and presumably, without the 7db loss in gain) in low SPL situations. I often record amplified acoustic shows that would never come near the levels which would distort the mics.

Kudos to Chris at SoundProfessionals for letting me pick his brain about this even though there was no revenue benefit to him - he's always been willing and eager to talk about anything audio.

I'll be using the new setup in 2 weeks (Fab Faux at Queens College), and I'll report on the results then.

Scott

[madman]

I'm surprised that people who run the SP BB with the 853s don't see distortion.  I ran those mics for a short time and only the quietest shows would end up distortion free.  Any loud rock shows would have horrible sounding bass, especially on the kick drum.  I don't see any reason not to go with 3 wire power.  Better safe than sorry with a distorted tape.

[poorlyconditioned]

I've ordered the 3 wire box from Sanjay, and he's also making a reverse connection for me (minxlr to 1/8") so I can use the mics with my old SP battery box (and presumably, without the 7db loss in gain) in low SPL situations. I often record amplified acoustic shows that would never come near the levels which would distort the mics.

Kudos to Chris at SoundProfessionals for letting me pick his brain about this even though there was no revenue benefit to him - he's always been willing and eager to talk about anything audio.

I'll be using the new setup in 2 weeks (Fab Faux at Queens College), and I'll report on the results then.

Scott

Yeah, I've had great experiences with Chris at SP as well.  He's always given me straight answers, eg., about what capsules he uses, etc.  And their work it top notch.  All cables are well soldered, heat shrinked, and drenched in hot melt glue!!

  Richard

[CHURCH-AUDIO]

Replace that 27k with a 4.7 k resistor and watch what happens distortion goes way down levels are not reduced as much.

Chris Church

i have never had a prob running the same exact set up, even beforei had the ad20 i had no probs

i take that back ONCE when my mics were seriously 5 feet from the stack i had distortion on loud bass
so i too don't understand what having a 3 wire box would do

There is nothing wrong with the regular setup, just that a 3-wire battery box (or phantom power) is an improvement.

Try it and you'll see the difference...

  Richard

would the 3 wire replace the sp box all together or is addition too it?

Yes, the three wire box would replace the SP box.  You would have:
  mics > 3-wire-box > pre/adc > NJB3
skip the pre/adc if you do line in.

  Richard

PS:  Hmm.  Perhaps Sanjay or I should put one of these in the gear loaner program.  Although you would need miniXLRs on your mics to be able to use it.

PPS: Note that neither Sanjay nor I are trying to fluff these for our own profit.  We are just addressing a need out there.  In fact, I haven't even sold one yet!  (Though I think Hyperplane may be my first customer.)  And if you want to build one, here is a (simplified) version:

[graemecogger]

Replace that 27k with a 4.7 k resistor and watch what happens distortion goes way down levels are not reduced as much.

Chris Church

What's the theory behind that, Chris?
These electret FET circuits are pretty much auto-biasing to a given current, regardless of the source resistor.  Reducing the source resistance should increase the distortion in a source follower circuit, not reduce it.  It would also significantly reduce the overload levels, since the 4.7k would have less than 1V across it.
I'm not saying that you're wrong - I'd just like to understand your thinking