Hello People I have Pot Arcing and Soft input issues .

[DJDestiny]

This is my pre amp :

With a 100k pot going out after the 470uf cap .
Yes , there is sound , but my strat IS acoustically louder then it .
And with this power amp :
http://www.futurekit.com/2009/manual...6/FK604E-2.pdf
It's hooked up to a 12Wrms 4ohm load .
But when i tried it with a line output ... the preamp pot smokes and arcs .

[firechief]

Does the FUTURE KIT work by itself? Which pot is it that arc's? is it the one on the FUTURE KIT? You will need to give us a more detailed discription befor we can understand.

[DJDestiny]

Originally Posted by firechief

Does the FUTURE KIT work by itself? Which pot is it that arc's? is it the one on the FUTURE KIT? You will need to give us a more detailed discription befor we can understand.

It does , if i just use the line in from something else , but it won't work as a guitar amp by itself , so i made this preamp , the 100k on the output of the preamp is smoking .
1 is to ground 2 is output 3 is input .

[firechief]

Ok well I have looked at the data sheet for the LM386 and it is able to put out 350 milli watts of power, so it may be that you are dumping that into the pot. You have a blocking capacitor between pin 5 and the pot so that means its not a DC problem, asuming it is wired just like the diagram. Really, the right answer is that you shouldnt use the LM386 as a pre-amp. You can do what you need with an op amp. It should be one with a high input impeadance to match your guitar (say 500K to 1M ohm) and the gain will be something on the order of X10. or mabe a little more. Look around for a Op amp pre-amp design. The parts should be realllllllly cheap.

[firechief]

You know what, on second thought this is probally a incorrect connection. double check your wiring.

[DJDestiny]

Originally Posted by firechief

You know what, on second thought this is probally a incorrect connection. double check your wiring.

It's been checked , with magnifiying glasses , nothing is incorrect .

[Nigel Goodwin]

Originally Posted by DJDestiny

This is my pre amp :

With a 100k pot going out after the 470uf cap .
Yes , there is sound , but my strat IS acoustically louder then it .
And with this power amp :
http://www.futurekit.com/2009/manual...6/FK604E-2.pdf
It's hooked up to a 12Wrms 4ohm load .
But when i tried it with a line output ... the preamp pot smokes and arcs .

Sorry, that's not a preamp, it's a small power amp - and you don't put a 100K potentiometer on the output of a power amp, even a small one.

Trying to feed a speaker from it means the pot has to be fully at one end, or VERY, VERY close to it. This means it burns the pot out.

The pot needs to be at the input of the little power amp, not the output - but what's wrong with the pot already in your guitar?.

[DJDestiny]

Originally Posted by Nigel Goodwin

Sorry, that's not a preamp, it's a small power amp - and you don't put a 100K potentiometer on the output of a power amp, even a small one.

Trying to feed a speaker from it means the pot has to be fully at one end, or VERY, VERY close to it. This means it burns the pot out.

The pot needs to be at the input of the little power amp, not the output - but what's wrong with the pot already in your guitar?.

it's feeding the power amp , who has a input impedance of 50k

[Nigel Goodwin]

Originally Posted by DJDestiny

it's feeding the power amp , who has a input impedance of 50k

Exactly, so you don't need another one.

[DJDestiny]

Originally Posted by Nigel Goodwin

Exactly, so you don't need another one.

The issue is about overdriving the power amp ...