I want to make a circuit to make the echo and reverb effect for my ampli
but i don't have any knowledge about this circuit
please help me a hand
thanks very much

 

There are a whole slew of build-it-yourself effects on this page:
http://www.geofex.com/

If you want to make a super-simple reverb, you could simply use a long tension-type coil spring (has hooks on each end, maybe 3/4" x 6" in size) in a metal box tensioned between a couple of jacks. Connect the jack's grounds to the metal box.
The tighter the tension of the spring, the higher the frequency of the reverb for a given spring.
The longer the spring, the deeper the reverb effect. If the spring is too long, the sound will get "muddy."

Select a spring that uses a fairly small-gauge wire (say, AWG 16 or less). Try several different sizes to see what I'm talking about.

 

There are a whole slew of build-it-yourself effects on this page:
http://www.geofex.com/

If you want to make a super-simple reverb, you could simply use a long tension-type coil spring (has hooks on each end, maybe 3/4" x 6" in size) in a metal box tensioned between a couple of jacks. Connect the jack's grounds to the metal box.
The tighter the tension of the spring, the higher the frequency of the reverb for a given spring.
The longer the spring, the deeper the reverb effect. If the spring is too long, the sound will get "muddy."

Select a spring that uses a fairly small-gauge wire (say, AWG 16 or less). Try several different sizes to see what I'm talking about.

Thank for your help
I will try to do it