Hiss Sound

[splashsky]

i built a preamp equa circuit for  a bass guitar the specs and circuit is shown below

I had some problems in the begin with clipping and all...!and its good

but there is a hiss sound (earth problems) when i touch the ground the hiss is no more

but no one plays the guitar with bare foot...  (at least on a stage)

can some one tell me how to solve it...

is there's any way like artifical earth...!  ::)



http://redcircuits.com/Page69.htm



spec:


P1,P2_________100K  Linear Potentiometers
P3____________470K  Linear Potentiometer
P4_____________10K  Log. Potentiometer

R1____________150K  1/4W Resistor
R2____________220K  1/4W Resistor
R3_____________56K  1/4W Resistor
R4____________470K  1/4W Resistor
R5,R6,R7_______12K    1/4W Resistors
R8,R9___________3K9  1/4W Resistors
R10,R11_________1K8  1/4W Resistors
R12,R13________22K    1/4W Resistors

C1____________220nF  63V Polyester Capacitor
C2,C8___________4µ7    63V Electrolytic Capacitors
C3_____________47nF    63V Polyester Capacitor
C4,C6___________4n7    63V Polyester Capacitors
C5_____________22nF  63V Polyester Capacitor
C7,C9_________100µF    25V Electrolytic Capacitors

IC1___________TL062  Low current BIFET Dual Op-Amp

J1,J2__________6.3mm. Mono Jack sockets

SW1______________1 pole 3 ways rotary or slider switch
SW2______________SPST Switch

B1_______________9V PP3 Battery

[audioguru]

Did you use shielded audio cable from the guitar to the preamp circuit and from the preamp to the amplifier?
Is the preamp in a metal box that is connected to the signal ground?
Is the amplifier connected to earth?

Does the hiss sound change volume when the output volume control on the preamp is adjusted?

[splashsky]

Did you use shielded audio cable from the guitar to the preamp circuit and from the preamp to the amplifier?

yes its a good one

Is the preamp in a metal box that is connected to the signal ground?

No, Its on my guitar onboard

Is the amplifier connected to earth?

Yes, because on the other guitars the hiss sound is not there when i Touch it..(with my shoes on)

but in this guitar the sound reduces (with my shoes) and there's nothing when i touch the ground with my bare foot

Does the hiss sound change volume when the output volume control on the preamp is adjusted?

no, Not much...