Topic: AT853's - Difference between 2wire and 3wire?

[justink]

i have the 2wire version from soundpros but was curious as to how the 3wire version differs and what the positive aspects of a 3wire set up is.  i believe sensitivity is one of the positives correct?  is there any audible difference?

what sort of converter would i need to run a 3wire using phantom 48v?

thanks.

[Cheesecadet]

2-Wire 853s will distort at high SPL levels without the 4.7k mod.  3-Wire offers full dynamic range and no distortion.

[Hypnocracy]

I have AT853's and a Church CA9100 both with 3 wire Mini XLR's...the reason I bought it that way was to have a switch on the Pre for the 4.7k Mod...that gives you the best of both worlds...High SPL with mod...or more gain for low level acoustic type shows

[justink]

so, the mod would cause you to turn the gain up higher, but not cause the distortion/brickwalling?

other than the distortion, is there any sound improvement?

[Hypnocracy]

The way I understand it...

The mod increases the microphones MAXIMUM SPL...at this db level I assume the Preamp is not being called on for much gain and maybe even applying attenuation would be needed...if the Max SPL at the venue is below 105db () taking the mod out of the chain increases the gain of the preamp or maybe it just doesn't cut it back I'm not sure. I'd defer to Jon Stoppable comments above for any other improvements.

IIRC...with Three Wire you can make a jumper with the 4.7k mod and insert it or not in the chain for the same result.

[justink]

i've only ran into the distortion issue once when i was kissing the stack.

in hindsight, could i have used a notch filter at 1k to take out the distortion?

[Humbug]

Only tried running AT853's two wire the once.

Distortion was so bad it was unlistenable. Mind you, it was a very loud band (Velvet Revolver), and I was running another rig as well, so I didn't lose the recording.

Love 'em now they're three wire.

[hi and lo]

Adding resistance from that third pin (the "source" pin of the capsule FET) doesn't decrease gain in the preamp, it decreases gain at the capsule FET, which can be a gain stage.  In three-wire operation, there is no gain at the capsule FET.  In two-wire mode there is usually some gain, although there can be none.  The important concept is the need for resistance, otherwise the capsule FET overloads easily.  Two-wire and three-wire will usually have similar max SPL with the same source resistance--with two-wire it also depends on supply (or "drain") resistance, but usually that figure isn't too high to muck things up.

Nice explanation here!