Hello,

This looks like a cool site, this is my first post, I found this site after struggling with making a little solid state amplifier for my guitar.

I wanted to make a quick amplifier so I went to the store and bought an amplifier kit: Velleman's K4003 kit which is based on a TDA2612 datasheet is here

http://pdf1.alldatasheet.com/datasheet-pdf/view/19262/PHILIPS/TDA2616.html

anyway, I hook up an mp3 player to this and no problem, sounds fine.... I hook up my guitar, and as soon as I turn up my volume knob.... noise! I can hear the guitar sound in all the noise, but the noise is terrible.... it's the same noise I hear if I leave nothing plugged up to the input of this amp...

so, I'm thinking:  My guitar is high impedance and this IC is made to use with low impedance signals... I tried putting an opamp buffer circuit between my guitar and amplifier to bring down the impedance, but that didn't work, I tried a non-inverting amplifier stage to boost my signal before the amplifier, that didn't work either....

any thoughts?

much thanks!