Please help me build a guitar amp.

[apakhira]

Hi
I have a box with 4 speakers- 2 rectangular 4W ones, a square 2W speaker and a tweeter. I want 2 make a guitar amp out of it. I'm thinking of using the LM386(that's what i think it is) 8W Audio amp IC. Now, do i need 2 have a pre-amp stage b4 the amp or just the amp will do?

Thanx

 

[Nigel Goodwin]

Hi
I have a box with 4 speakers- 2 rectangular 4W ones, a square 2W speaker and a tweeter. I want 2 make a guitar amp out of it. I'm thinking of using the LM386(that's what i think it is) 8W Audio amp IC. Now, do i need 2 have a pre-amp stage b4 the amp or just the amp will do?

Thanx

You need to have a preamp, a simple opamp will probably do, although it's as well to add tone controls as well.

 

[apakhira]

I have a circuit 4 a 3 band tone control. (Attached here)Please see it. I think if i use this there wouldn't be any need 4 pre-amp cuz that's what i think the 1st op-amp does. Tell me if i'm right.

 

[ag]

Yep, that'll do it, stick your LM386 after all of that.

 

[audioguru]

The LM386 has a maximum output of only about 1/2W.
Maybe you are thinking about an LM384.

Won't those tiny low-power speakers sound kinda tinny?

 

[apakhira]

The LM386 has a maximum output of only about 1/2W.
Maybe you are thinking about an LM384.

U r right. I told u i forgot the name.

Won't those tiny low-power speakers sound kinda tinny?

Yeah i know. I was just trying to find some use for the speaker cabinet with the speakers which i built when i was a kid. (I can still b called a kid now) Anyway i'm thinking of adding an output socket to drive another speaker when i want, maybe.

 

[apakhira]

Guys, could u tell what the value of R2 i the circuit i attached should be? Also, will increasing the value of R1 decrease the gain or increase it. To in corporate a volume control could i put a pot instead of R1 or should i put a separate pot after or before the circuit?

 

[audioguru]

Please try attaching your schematic again.

 

[apakhira]

here:

 

[apakhira]

here:

 

[audioguru]

A quick Google search found this one, that looks the same.
Note that your circuit also needs an input resistor and maybe also an input coupling capacitor.
**broken link removed**

 

[apakhira]

Thanx.