Circuitbenders Forum

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: A possibly obvious question about adding an audio out.  (Read 4308 times)

Signal:Noise

  • Closer to the meat
  • *****
  • Karma: 16
  • Offline Offline
  • Posts: 291
A possibly obvious question about adding an audio out.
« on: June 08, 2006, 01:17:12 PM »

I need to add an out put to the SA-21 I've just modified because the built in output bypasses a couple of teh bends. I checked the tips page and it's got that handy diagram, the only problem is I can't figure out which wire from teh speaker is the ground and I'm too new at this to know if it matters.

Logged

papaspank

  • Guest
Re: A possibly obvious question about adding an audio out.
« Reply #1 on: June 10, 2006, 03:06:57 AM »

To Be really honest

I've only really noticed a porblem with polarity, when you have a stereo speaker set up.

Essentially - when one speaker, in a stereo system is wired wrong (+ to - not + to +) you get what's known as a 'phase' problem. Which means that as one of the speakers is pushing the air, the other one is moving backwards - kind of sucking, really. The overall volume gets reduced, and (in the magic world of theory) could cancel each other out ( perfect anti-phase)

So  -  I wouldn't worry about it really.

 :)

However!

What I would recommend - is put some small resistor (preferably one of those ones that can be adjusted with a small screwdriver) on the new output, to ensure that it's not too 'hot' (loud basically).

And if you do use one of those small screw-driver adjustable variable pots  - you can then 'zero' it - so that the output volume of the speaker, and the output volume of the jack output are fairly simmilar in volume.

hope that helps

 ::)
Logged

Signal:Noise

  • Closer to the meat
  • *****
  • Karma: 16
  • Offline Offline
  • Posts: 291
Re: A possibly obvious question about adding an audio out.
« Reply #2 on: June 10, 2006, 09:46:12 AM »

Cheers man, I didn't think there would be a problem, but I thought I'd ask seeing as I didn't want to terminate my expensive mixing desk.
Logged

Circuitbenders

  • crustypaul
  • Admin
  • This person is dangerously insane.
  • *****
  • Karma: 1102
  • Offline Offline
  • Posts: 2444
    • Circuitbenders.co.uk
Re: A possibly obvious question about adding an audio out.
« Reply #3 on: June 10, 2006, 02:20:45 PM »

I think the + is the blue speaker wire judging from the picture you posted on the other SA-21 thread, at least on every one of the small toy speakers i have in a box that i can't bear to throw away, the + is on that side. In fact i wouldn't be surprised if you take a very close look at the white bit on the speaker where the wires solder on you might find some tiny + and - markings.
Logged
i am not paid to listen to this drivel, you are a terminal fool

Signal:Noise

  • Closer to the meat
  • *****
  • Karma: 16
  • Offline Offline
  • Posts: 291
Re: A possibly obvious question about adding an audio out.
« Reply #4 on: June 10, 2006, 08:48:00 PM »

Had a closer look and it was just as you said, little '+' and '-' signs. Turned into something of a mission in the end but it's in there. Now all I need to do is add a switch to selct between output and speakers.
Logged