thanks everyone for the tips... the noise I get is hissy and whiney and seems to change a little bit in frequency when I play guitar.  It's kinda high pitched and always present, also turns up when I turn up the gain on my PreAmp.  It does completely dissappear when I unplug my preamp from the amplifier.  And I am doing most of this stuff with long leads with alligator clips to connect everything to and from my amplifier (preamp, speakers, power... all alligator clips)... I'm hoping when I put all this on a board that the noise will go away. 

The main cause of my noise was my guitar cable was hooked up backwards?! I didn't even know there was such a thing?! I basically have a small box with an input jack on one side and terminal block on the other... I break out the tip and ring (I think that's what its called) from the input jack into the terminal block, and then tie wires to the terminal block to whatever I'm doing... I swapped the wires and a ton of the noise went away...

here's some things I've been trying with the preamp

much thanks!

So I got a TL072 OpAmp, and have it set up non-inverting with a 47uF bypass cap at the input going to ground.  This cap gets rid of most of the noise when the input is left unplugged or at high impedance (like my guitar).  This works ok when plugged into an mp3 player as my input, but I still get nothing from my guitar...  and to add my issues there's 8V DC sitting at the output of my output cap C4... apparently capacitors don't block DC at my house....

I've plugged in different guitars and basses, they all sounds the same, when I crank up the volume, it gets noisy... I don't know what a screened lead is.  I was thinking it was too high of an impedance for the amp that is causing the problem... I dunno I'm stumped

1. I just picked whatever kit they had at my local electronics store and it happened to be that one
2. I have two 4 ohm speakers, one hooked up on each channel
3. the guitar is tied in to both input channels

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!