diy tubescreamer trouble

Started by tayste5000, March 24, 2011, 10:36:32 PM

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tayste5000

hey this is my first post. I am an avid musician who could not resist the temptation to explore diy electronics. I have successfully built a (germanium! :icon_mrgreen:) fuzz face, and a green ringer. I am very close to adding a tubescreamer(ts808) to that list, but it is not really working..........it does make some sound, but it is very quiet and undistorted. I used the GGG schematic. I soldered it all on a busboard, had 2 strips(i used for ground, V+ and Vbias, just cut one strip to separate V+ and Vbias) running down the middle of the length, and then 60 strips  running from the edges to the strips in the middle(not touching them). i have checked and rechecked the circuit path several times and tested many suspicious jumpers for continuity, but to no avail. i had some trouble with the green ringer, but i was able to solve it myself. this time it is not looking likely. i know my best bet is redo it, probably with perfboard instead. but before i do that, here are the voltages of the IC and transistors(they show signs of faultiness, signs i cannot read). if anyone has any suggestion on something specific i could check, or think they might know the problem, i would be very thankful.

battery-8.29v

IC

pin1-4.09v
pin2-4.26
pin3-4.02
pin4-0
pin5-4.09
pin6-4.10
pin7-4.10
pin8-8.22

Q1
E-3.44v
C-8.21v
B-4.06v

Q2
E-2.78v
C-8.20v
B-2.39v

the transistors are 2sc1815, which is why they are in ECB, and i was not are they were like that so i wired them wrong at first, but i fixed it, but i could have botched that too, but i have checked the bejesus out of those points in the circuit and see nothing wrong.

and please, have mercy on me, i...........am.........a..........NOOB! :icon_eek:

petemoore

#1
  Buffers with BJT transistors I'm assuming:
 Q1
E-3.44v
C-8.21v
B-4.06v

Q2
E-2.78v
C-8.20v
B-2.39v
 Base above emitter by a diode drop is the 'rule' for BJT's.
 Looks like something's pulling the base toward ground, or something isn't pulling the emitter toward ground hard enough.
 Measure/compare the DC bias component values while performing distant point testing [ie from transistor pin to say distant-est ground you can find through the base to ground resistor.
 "EBC" is a 'usual order of the pinline where they come out of the transistor body, there are other pinout configurations. Use the data sheet to determine the [hopefully] correct pin orientations of your BJT  transistor, then double check each one is correctly assigned to it's node.
Convention creates following, following creates convention.