How to pre-record voice module from PC, avoiding using microphone?

Hello. Could anyone advice me, please? I read all of the QA related, but my question would be a bit specific.

My intention is to make a greeting card like device, using recordable voice module. Recording your own message by using the microphone is pretty clear. However my concern is, I would like to pre-record this module with any music or jingle from the PC and leave user the option either to record her/his own message using the attached microphone or let that pre-recorded jingle play.

I would use any of this type or similar modules shown on picture. Thanks in advance.

Picture of How to pre-record voice module from PC, avoiding using microphone?
ggom2017 days ago


that looks pretty easy , only this 8 ohms resistor to the earphone output of your computer that will make the sound card happy about impedance, then a simple 2 resistors divider will attenuate the level.


output from soundcard: 500mv

Max input needed : 100mv

divider 500/100=5

8 ohms to load the output

a divider bridge with 4.7 k on signal out

and 1 k to the ground .

the mic + out took from the common between the 4.7 and the 1k

Add a 10 microfarad for continuous current insulation .

(schematic if needed.)

an other choice is to find a cheap 6 $60 all in one module:

I don't assume any risks about that link :


iceng24 days ago

Just program the a blank black blob with the same code over and over and you get it..

Or ask a firmware furnace to blob them for you !

If you want to get sound on it without a mic it means you need to match the audio output level of your soundcard and the output voltage/impendance to that of a microphone.
Will be next to impossible without a lot of tinkering.
Easiest option IMHO would be a transformer.
Soundcard side wired up to 4 Ohms to keep the soundcard happy, output side with only a few turns then going into a level shifter to get the required DC by adding what is needed.

Working with a simple resistor splitter might work too depending on the module handles it.
Here you could use a good (audio rated) potentiometer (around 10k Ohm) and use the adjustable pin to feed the module.

In either case keep in mind that you need to make a connection from negative of the module to the case of your computer to avoid bad interference.