The RPi uses standard line level audio as found in TV or other audio equipment. Red and white RCA jacks.jjh76 wrote: ↑Mon Aug 06, 2018 12:41 amI'm using a TIPI with my TI-99/4a. The TI-99/4a has an audio input line on it's expansion port. Here is a link to the data sheet for the sound chip it uses:
How much power is sent through the trrs jack on the 3b+? Going by this data sheet, would it be safe to connect it directly to the audio input line on the TI, or would I need to put some kind of level shifter between them?
Professional audio equipment typically defines "Line Level" as 0 dBm into 600 ohms balanced. 0 dBm is 1 milliwatt. From Power = V*V/R that corresponds to 775 milliVolts RMS into 600 ohms. Multiplying by '2 root 2' yields the peak-to-peak figure 2.19 volts.
Burngate wrote: ↑Tue Aug 07, 2018 7:49 amNo. Tip = left, ring = right, ring = ground, sleeve (you called last ring) = video.
Raspberrypi-spy has a good description (as with many things)
https://www.raspberrypi-spy.co.uk/2014/ ... ideo-jack/
Yes. It's designed to be used that way - with standard earbuds. The video circuit can happily be grounded without harm
No. The voltage level will stay about the same, and so will the power.Also, if I were to combine the stereo audio outputs into mono would that double up the power level on the mono line?