need help in ISD2590 chip

[ktkoota]

hello,
how can I record from mp3 player to ISD2590 chip.. the manual shows recording from microphone but from other source Ihave no idea.. what are the necessary connections needed(in modes and addreses)..
Regards

 

[Hero999]

Connect the headphone outlet from the MP3 player to the mic inlet via a suitable attenuator.

I'd probable use 47k and 1k resistors to make a potential divider to reduce the output to a low enough level.

 

[ktkoota]

I connected the headphone outlet directly(without any attenuator) to the mic inlet but the sound heared from the chip has many noise (why is this in terms of Volt and Frequency)..
are the 1K and 47K resistors enough attenuator and which one is connected to the ground?


Regards

 

[Hero999]

The sound was probably distorted because it as clipping.

The 1k goes between 0V and the ISD2590 input and the 47k goes between the MP3 output and the ISD2590 input.

Don't use both headphones, unless you use two 47k resistors.

Post a schematic and I'll tell you if you've done it correctly.

 

[ktkoota]

I posted the schematic so that you can check it for me please..
I didn't get : Don't use both headphones, unless you use two 47k resistors..

**broken link removed**

 

[Hero999]

No, I mean like this.

Do you wish to connect both channels?

If you, use a 47k resistor for each.

 

[ktkoota]

Hi Hero,
thanks for your help..the noise has been reduced but still appeare with sound and how can I controle the volume of the sound because I need a louder volume than the resulted one?

Regards

 

[Hero999]

Increase R3 to 2.2k.

 

[ktkoota]

and the sound volum how can I increase it?
can you please explain to me how do you choose these values of resistors?

 

[Hero999]

I've just told you how to increase the volume.

I used the potenrial divider formula.

Unfortunately, I don't know what the voltage is from your MP3 player so I had to guess.

You could've also reduced the value of the 47k resistors.
Voltage divider - Wikipedia, the free encyclopedia

If the volume is still too low, try increasing the 2k2 resistor to 4k7.

 

[ktkoota]

what is the sound card voltage from labtops? if I connected the headphone to this recording chip what will be the appropriate resistors?

 

[Hero999]

I don't know, it depends on the volume setting and how loud the music is.

Using a pot. for R3 will enable you to control the volume.

 

[ktkoota]

thank you Heroo,
just one problem left ,the sound is not that pure as hearing it from computer..why?

I if the voltage from the sound card is 4.7mv what will be the appropriate resistors, can you show me the caculations>

 

[Hero999]

IF the voltage is 4.7mV you don't need any resistors.

If you've measured that with a DVM, it's wrong, unless you played a pure 50Hz sinewave through the sound card.

The sound won't be as pure because the sample rate of the the ISD2590 is much less than your PC's sound card.

The formula for calculating the resistor values can be found on the Wikipedia article I linked above.

 

[ktkoota]

Hi,
can you tell me the function of capacitors and resistors in this circuit?

Regards,
Ktkoota

 

[ktkoota]

Dear Hero,
what do you think if I connected the mp3 headphone outlet to the ANA IN pin coz it has amplifier(please see internal circuit of the ISD2590).. the voltage from the headphone is 1.5mv and the mic inlet accept max 20mv so we need to amplify it not divide it .. am I correct??
Regards,
ktkoota

 

[ktkoota]

where are you hero.. I did it and the sound amplified ..