Damage if connect the output of the headpone implfier to the input of the speaker amp

[mkioiuq1]

I want to build a small project with just an Arduino, a radio receiver and 2 speakers.

I have bought a small PCB with a TEA5767 radio FM chip . The audio output is however fed directly in a headphone amplifier chip TDA1308 from NXP (datasheet). The rated maximum power output of the TDA1308 chip is 80mW.

I want to however feed the audio into two speakers. For this purpose I'd like to use the PAM8403 stereo audio amplifier (datasheet). This chip is rated for 3W output power.

Would it damage the amplifiers or the speaker if I were to connect the output of the headpone implfier to the input of the speaker amplifier? If yes, what's the best way to get the audio to the speakers? Should I convert the amplified signal to line-level again and then amplify it again? Or would be easiert to just desolder the headphone amplifier and grab the TEA5767's audio output directly?

I've searched for similiar questions on this board but nothing came up. Thanks for your help.

 

[HormusPeston]

Re: Damage if connect the output of the headpone implfier to the input of the speaker

Hi mkioiuq1,

I remember making matchbox radios in the early 90s with the TEA5591. Great chip. My suggestions:

1) The PAM modules will clip if you try to feed them directly from the 1308.
2) Desolder the 5767 module from the board and connect it directly to the PAM.
3) I'm not sure if the PAM will generate RF interference to the extant that they disturb the FM reception?

Cheers,

~HP

 

[greenhorn]

Re: Damage if connect the output of the headpone implfier to the input of the speaker

in my opinion, wouldnt be an issue, but you'll get a lot more noise, interference etc. If you find any clipping, add a series resistor/voltage divider at the ouput

 

[HormusPeston]

Re: Damage if connect the output of the headpone implfier to the input of the speaker

Hi,

Is this to be a low-power application that requires the use of the PAM module? Why not use the good old LM386 instead?

Cheers,

~HP

 

[HormusPeston]

Re: Damage if connect the output of the headpone implfier to the input of the speaker

Founder of the Cheapskate Audiophile Society - Members welcome

Hi Greenhorn,
I'd like to join your good society, please. Where do I sign up?
Cheers,
~HP