Having trouble placing or receiving calls or using your voicemail system on Ooma Telo VoIP Phones? Post your questions here.
- Posts: 554
- Joined: Fri Jun 11, 2010 2:02 pm
- Location: Portland, OR
As the Rackety Coon Chile said, all you need do is feed analog audio to the telset input on the Telo, which ought to have an impedance of a few hundred ohms (600 Ω ideally). Do that through a transformer secondary, which can even be in series -- or parallel -- with an ordinary analog telset. I would use a transformer whose other winding was of about 10 to 20 Ω and feed it from a speaker output of an amplifier. That way I can have in the line all the processing ("sweetening") of which my audio systems are capable -- gracious plenty in my case. Also I have full control of the volume. Also it's easy.
Don't worry if the impedances are off, even by a factor of five or more. Actual speakers, while a nominal impedance is stated -- usually 4, 8, or 16 Ω -- actually vary in impedance unit-to-unit, and vary even more by frequency. Also the speaker impedance is profoundly affected by the acoustic environment in which the speaker is mounted (Is it in an enclosure? How big? Ported, or infinite? and so forth), and therefore the amplifiers that feed them must be, and are, very tolerant.
Try it. It'll be fun, and it'll work, too.