Finished DS-1 !!! worked fine !!! But now ...

[LiquidSteel]

Hi

I wanted to know how an 4558 ic sounds in the ds-1. when i changed the ic the ds-1 was connected to the batterie, the 4558 didn't work, and when i put back the Tl072 the ds-1 doesn't work right, when i adjust the distortion potentiometer to full distortion, the sound dissapears, with less distortion it works. That's not fair ... it have worked, but now .. aaahahah

What could be the problem, is perhaps a transistor broken ??
Can somebody hlep me

[petemoore]

Are you using a socket for the opamp?

[LiquidSteel]

yes ... i've just tried some other oamps, but always the same

[nelson]

See the sticky "what to do when it doesnt work" and post voltages....best way to get help by proxy.  


just a bit of an inexperienced guess, "over saturation"?

[LiquidSteel]

here are the ic voltages ...

pin1: 3,7 V
pin2: 3,7 V
pin3: 3,7 V
pin4: -9,2 V ( 0V )
pin5: 3,7
pin 6 and 7 depend on the distortion: full distortion: pin 6: 2V ; pin7: 8,6V
min. Dist: pin 6: 3,7V ; pin 7: 4V
pin8: 9,2 V ....

i think this voltages are allright .. soon the transistors voltages

[LiquidSteel]

here the transistor voltages

Q1:

c: 9,2 V
b: 4,46 V
e: 4 V

Q2:

c: 0,8 V
b: 0,6 V
e: 0,02V

Q3:

c: 9,2 V
b: 3.5V
e: 3,3 V

[LiquidSteel]

when distortion is full adjusted, it sound like a bad contact, like somebody rubbing a contact ,,,, but wehn the distortion is minimum, everything is allright

[nelson]

Sounds like your pot. Change the pot see what happens.

[LiquidSteel]

i've tried two other pots .. the same ...
when i "hit" my guitar strongly on full drive setting it almost works, but i have to play very strongly

ahaha ... why did it stop working ... everythink was perfekt

does somebody know if the voltages are allright ??

[petemoore]

I'm not sure about the opamp voltages, could be an offset bias.
 Q2, with nearly 0v on the pins of course can't work.
 The other transistors need at least a diode drop voltage difference between B/E.
 Probably something like a trace or piece of wire between traces...

[LiquidSteel]

hi .. all transistors have a a B/E voltage of 0,61 - 0.63 ... i checked Q2, everythink is allright, 0V on the C can't be, thats allright, but with low distortion it works fine ... i'm going to check the components near Q2

[LiquidSteel]

nobody an idea