Old phone into a Mic
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Posted on Nov 21, 2011 01:32 pm
FunkDadyP
No Commercial Appeal.
Member Since: Jan 09, 2003
Hi guys. It's been a loooong time since I visited the site and I figured you guys might have the answer for me.
I'm by no means a pro with wiring, but I know how to solder and work in a place with tons of resources for that type of thing. So here's the question:
I want to turn my old phone (touch tone buttons in the handset) into a mic. I've got a cable all ready to use. I want to make it an easy transition to a female XLR.
I found the wiring diagrams for the XLR and RJ11, but I'm not sure what to do with them:
pinouts.ru/GPS/gns_gps_pinout.shtml
pinouts.ru/Home/xlr3_pinout.shtml
Obviously the ground goes together, but is the fact that there is a "shield" from the XLR make this more of a task than I thought?
I can actually buy an adapter from a few online places, but they're like $25 and I can do it for free if I can figure out exactly how.
I also did a quick search of past forums and someone suggested a link, but it's gone now.
Anywho, it's good to be back and I can't wait to hear from you guys.
Love always,
The FunkDady
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Nov 21, 2011 08:11 pm Hey FunkDady, haven't seen you in a while.
So, what is the goal of this phone project? Is it just to get the old phone sound? Or you actually want that for a mic for some reason? I am no expert in wiring so I can;'t help for that much, but, for the old phone sound, if I recall correctly you just need to boost mids and roll off highs and lows...
FunkDadyPNo Commercial Appeal.Member
Since: Jan 09, 2003
Nov 22, 2011 07:26 am Not just the old phone sound for recording but also to play out live. My buddy who created one himself finally got back with me and he said it's mega easy. The hardest part is getting the phone to come apart in one piece.
He said you just take the two mirophone wires off of the handset and splice them to the two wires in the XLR.
I really want the phone to be able to play the touch tones too. Maybe have a quick touch tone solo! He said it may not have enough power, even with phantom power, to make that happen, but it's worth a shot.
It seems like about the most simple wiring project one could do.
Thanks db
HuePinnipedal Czar (: 3= Member
Since: Apr 11, 2004
Nov 22, 2011 08:47 am Welcome back FDP!
I seen a band use one of these mics on stage once. Pretty cool context, as well... He was speaking/singing one part of the 'conversation' into a regular/dynamic mic, then switching to the phone for the other side of the conversation. It was interesting, and worked well. 'Sounded good, too.
Great idea for the touch-tone solo!
Nov 22, 2011 04:19 pm Try pin 1 of phone to pin 1 of XLR, pin 2 of phone to pin 2 of XLR.
I would snip the wire on the phone piece and solder to that instead, or drill the hole for the cable big enough to run your mic cable in, and solder it straight to the microphone. That way you can scrap the base. You might want to add a capacitor in series with the hot pin to block phantom power, or use a jack plug instead.
EDIT: Oh, but then you won't be able to use the tones :-).
Nov 22, 2011 04:49 pm Humm. Interesting.
For the phone it's self. Who cares where the which wire of the phone goes. You don't have another that you are using in on the stage at the same time. So polarity means nothing at that point. Just take either of the two wires that lead to the reviver, and put them on Pin 2 and 3 of the XLR.
For the touch tone, that's a little more tricky. The touch tones don't go to the mic. They go to the speaker in the phone. You would have to run a jumper wire from the op amp that runs the speaker, and jump them down to the XLR. You would also have to put in a few diodes to ensure that the mic doesn't get hit with the voltage when hitting the buttons. Plus, you are going to need a 9v battery to power the circuit for the touch tones, and the op amp as well.
Do you have the schematic for the phone?
FunkDadyPNo Commercial Appeal.Member
Since: Jan 09, 2003
Nov 22, 2011 08:27 pm I don't have the schematics, no.
As far as not hearing the touch tones, I don't think that's right. When I'm on the other line with someone and their fat face mushes the buttons, I still hear the tone. Maybe it's done another way, but I'm pretty sure it'll be audible.
I think my best option is to splice the RJ11 to XLR rather than connect directly to the phones mouth piece.
I'm guessing none of you have used an XLR to RJ11 adapter. Like I said earlier, they're like $25. I think it may be worth the money just to eliminate headaches and hours of soldering, testing, resoldering, testing etc. I don't know. I would like to try this though. Thanksgiving weekend may be too busy however.
But when I finally try it I'll definitely let you guys know what the deal is. It's gonna be awesome, I know it!
Nov 22, 2011 08:29 pm I am suddenly intrigued by this idea...might make for a fun project...if you find it to be a successful project, document it, or video a tutorial, I'll post it up here for us all to enjoy. Could be fun funkiness for some old phone that isn't good for anything else.
FunkDadyPNo Commercial Appeal.Member
Since: Jan 09, 2003
Nov 22, 2011 09:50 pm I don't know how riveting a tutorial would be when I decide to just buy the RF11->XLR adapter. Ha! That may be my first course of action just to see if it'll be that easy. I'll probably try the splice if it's not successful.
Nov 22, 2011 11:44 pm Trust me FunkDadyP, the audio does not route through the mic. Or mouth piece. The mic inside all phones are passive. You can not pass line level signals through a passive device such as a mic. In doing so, you would turn the mic into a speaker.
Now depending on which phone that you have, you maybe able to power the whole phone off of the phantom power. In looking over some schematics on the web, I found may that use 48V to power it up.
What model are you looking to use? Maybe I can find the schematic for you, and come up with a wire diagram.
FunkDadyPNo Commercial Appeal.Member
Since: Jan 09, 2003
Nov 23, 2011 12:39 pm I think it's model is an AT&T 210.
If I somehow ran power to the phone base and then used the RJ11 to XLR adapter I was talking about (or spliced the RJ11 to an XLR), wouldn't I be able to get the touch tones?
I'm thinking just splicing straight to the handset microphone might run me into problems in the future if my soldering skills are the best, and they aren't.
And yes, my mixer has the 48v phantom power. I was wondering if that would be enough juice to power the touch tones.
Really I just want to get the mic working, but the tones would be a definite plus.
FunkDadyPNo Commercial Appeal.Member
Since: Jan 09, 2003
Nov 28, 2011 10:42 am Ok, I tried to splice an RJ11 cable to the XLR and RJ11 conductor wires are TINY! I tried for about 25 minutes just to strip the wire and I couldn't get the thing to strip without damaging or cutting the inner wire completely. I looks like there are only two wires inside each of the four conductor cables.
My friend that made a phone mic just spliced directly to the handset's microphone wires, but like I said, I want to get the touch tones to come through.
I'm thinking I'll either have to find a phone junction box and splice from there, or just buy the stupid RJ11-->XLR adapter.
I'll keep reporting back on what I'm doing. I'm convinced that this will work.
FunkDadyPNo Commercial Appeal.Member
Since: Jan 09, 2003
Nov 28, 2011 11:00 pm I MADE IT WORK!
The touch tones work and everything! It's super easy. I took one of the junction boxes (you know, the thing that is hanging on your wall that connects your phone to the outside line) and opened it up.
There are four wires. The two outside wires (black & yellow) are grounds (as far as I can tell). The box I took off my wall had the yellow wire cut at the base of the RJ11 connector. The two middle wires (red & green) are the audio connections.
Each wire, except yellow, had a lead connected to a post (really just a screw and washer). I stripped the XLR on the male end and it exposes a yellow and red wire, as well as two separate grounding wires.
I attached the red XLR to the red RJ11 post and the yellow XLR to the green RJ11 post. I also twisted the two ground wires together and attached it to the black, ground post.
I plugged in my phone into the junction box, flipped on the phantom power and BOOM! That mofo runs REALLY hot. I've got the gain set really low, but it sounds cool. I'm running my SM57 in tandem on the next channel just to see the sound difference and it's pretty neat.
The touch tones are coming through perfect. I was hoping the "pulse" option on the buttons would work a little more rhythmically, but it's not quite there.
Anyway, there you go! It's possible to make a kick *** phone mic for zero dollars....minus the cost of an old crappy phone and an XLR.
Looks like I won't be buying that $25 adapter (plus $8 shipping). Sweet. New toys!
Nov 28, 2011 11:10 pm AWESOME! Glad to hear that you got it up and running.
I was searching for the schematic for you when I was that you got it up and running.
I see that the gain is coming out hot. How is the gain before feedback? I would assume that since it's more of a cardioid pattern, that you should be able to get some decedent volume before it explodes into feedback.
Nov 29, 2011 06:58 am Interesting...and glad you got it to work. One of the grounds, I believe, is a low level power source responsible for any lights on the phone and such things...may want to look into that before using it in any loud, power sucking applications.
Just food for thought...
Dec 01, 2011 07:49 am Quote:
I MADE IT WORK!
Haha, great! Really want to try this now.
