External Microphone (not a headset)

[cmathews1979]

I would like to use a self-powered condensor mic with my treo to record sounds on the go. However, I'm having trouble finding an adaptor. Does anyone have any suggestions? I can get adaptors for the XLR to 1/8", 1/4", etc if needed. I need the part to go from the internal 2.5mm to some isolated input jack. Even better would be an adaptor that gave a Y-split with one side being stereo-out and the other side being mono-in. Thanks in advance.

[TazUk]

I'd get hold of a wired stereo headset, chop off then end and then solder on some sockets. Not very pretty but it should work

[hewson]

I am also looking for the exact same thing, especially since that great meteor multitrack recorder already exists and works great with the treo 700wx. anyhow, here are two pinout diagrams if someone wants to give the adapter a shot!
PalmOne Treo 650, Treo 700w, 750v, Tungsten T5, E2, TX, 680, LifeDrive interface port pinout and signals @ pinouts.ru

[**EDIT!!** - this 4-pin pinout seems to conflict with the three-pin pinout, see below] PalmOne Treo 700p 4-pin headset diagram pinout and signals @ pinouts.ru

PS I am ordering these connectors from mouser electronics -- i'll post if i get around to actually soldering something up...
171-7425-E

[hewson]

augh, the connectors i ordered are different dimensions (even though they look right -- they are very slightly shorter than the palm connector)... also, the surrounding part of the jack is too wide and runs into the palm's plastic case. BAH! here is what i ordered:
http://www.mouser.com/catalog/specsheets/KC-301089.pdf

unfortunately, i learned this after lots of painstaking soldering!

i guess the easier solution would have been to hack up a headset as TazUK mentioned... $#@$#@

[hewson]

ok, i obtained some random mono headsets -- unsure if the treo somehow completely reassigns its mic pins when connected to a three pin mono connector as opposed to the four pin, but as far as the three pin goes, the mic connects to the tip (pin 1) and ground, as shown here:
PalmOne Treo headset schematic pinout and signals @ pinouts.ru

this is an interesting contrast to the previously posted 4-pin diagram which shows the mic at pins 3 and 4...?

anyhow, i didn't obtain any 4-pin stereo headsets to mess with, so i can't confirm or dispute that diagram, and can only speak to the 3-pin at the moment... my findings were not very reassuring:

merely connecting a shure sm58 to pin 1 and the ground will result in the treo not recognizing that the mic is connected at all (and instead the treo will continue using the internal mic).

connecting a shure sm58 to pin 1 and the ground WITH an XLR > unbalanced line transformer in between will cause the treo to record from the mic, but with lots of noise and very low volume.

i then noticed that the mono headsets appear to have some sort of resistor in between pin 1 and ground, but when i tried to transplant the resistor to my shure sm58 setup, it did not "fix" things.... (the treo would not recognize, or the noise would not go away).

this seems to indicate that wiring up hi-quality audio input to the treo headset connector is a pain in the a$$.. although i suppose one would need to carve apart a 4-pin headset to make sure...??

PS- Tried the 4 pin... the 4 pin schematic is correct, but the treo either has problems recognizing the mic or records with lots of noise... the treo headset input is $@#&$@ sensitive!!!