transistor amp not working after shorting output

[Netlist]

Looks good. Did you change the diode?

 

[sg97]

yes i did same orientation as old one

 

[sg97]

plus at bottom minus on top of diode

 

[sg97]

like this

 

[Netlist]

Diode is OK.
Now, we will power the amp without the big output transistors.
With the bulb in place.
Then measure the DC voltage between those two resistors and see if you can change it with the potmeter R11.
It should be around 27V.

 

[sg97]

it is 27v i can change it iwth the pot i did not go all full left and right on pot just in case i dont brake something but i did small adjustmets both ways and it increases and reduces

 

[sg97]

btw 27v is in the middle of the pot

 

[Netlist]

Nice, now connect that little speaker and play some music.
Listen if it's not distorted at low volume.

 

[sg97]

will check it now

 

[sg97]

distortion is there but it was not like before , also volume is bigger this time

 

[Netlist]

If you lower the volume, does the distortion go away?

 

[sg97]

not really

 

[Netlist]

OK, connect both big transistors and try again with low volume.
Watch that no parts get hot. A bit warm is OK.

 

[Netlist]

Also, make absolutely sure the heatsinks don't touch each other.

 

[sg97]

btw pinout for these 2n3055 is same as my old ones ? i ask just in case

 

[Netlist]

Sure

 

[sg97]

i connected them same way as old ones

 

[sg97]

i will put shrink tubes over transistor pins if all works out in the end for now they are like this

 

[sg97]

should i power it now ?

 

[sg97]

i did power it and it works all is working but i have humming sound , when i put my finger on heatsink sound is clear, how to fix this ?