please help my fuzz is sick

[Michael]

Well....

I built a fuzz /standard from GGG) it worked fine, and i then wanted to add a input blend and a output blend... and while i was at it i soldered in the transistors... before that they where socketed.

Now my fuzz doesnt work!

It get this insane buzzy/crackling sound, thats gating and so on.

Its weird because if i hit the strings soft i get no sound at all, but hit them hard and i get the above mentioned mess...

So... somethings up... but have i fried the transistors? does this sound like the type of "sound" i would get after soldering a tranny to hot?

Or do you think its something else?

I used the methods in this thread for the blends, and i did use heatclips (testclips) on the transistorlegs (not sure if that helps).

               10uf
            I------I I-------I
            I                    I
            /----I              I
            /----I              I-------OUT   
   IN-----/    100K         I
            I                    I
            I------I I-------I
                    .005uf

http://www.diystompboxes.com/smfforum/index.php?topic=53374.0


hope you guys can help me! im a novice by the way... so anything you can think of just say it.

Mainly im thinking if you know the symptom/sound i described (and what to do) and the tranny heat issue.

Regards
Michael

[caress]

that sounds like the transistor is misbiased.  try a trimpot in place of the resistor from the collector...

[Michael]

i allready have a trimpot in place of the 8k2 resistor and that doesnt help.

no matter what position.

Michael

[John Lyons]

By "output blend" do you mean something similar to the input blend you show in the post above?
The input blend is going to have the most noticable effect on the signal because it sets the frequency responce that the pedal uses.
At the out put it's mainly just a matter of a larger value cap = full sound and a small value will cut bass. .1 and over will be full, .01 and under will thin ouit the bass.
You may need to post the voltages of the transistors.
John

[mountainking]

Hi, I'd double check the input connections and make sure that the input signal is going through a cap before it hits the base of the transistor. If the input signal is shorted to the base, you'll misbias the transistor and get some bad sounds, if you get any sound at all.

[Michael]

By "output blend" do you mean something similar to the input blend you show in the post above?
The input blend is going to have the most noticable effect on the signal because it sets the frequency responce that the pedal uses.
At the out put it's mainly just a matter of a larger value cap = full sound and a small value will cut bass. .1 and over will be full, .01 and under will thin ouit the bass.
You may need to post the voltages of the transistors.
John

Yes i made the same type of blend control using the diagram (you made it actually) for both the out put (normal caps) and the input (electrolyt caps).

How do i measure the transistors voltage?

Michael

[John Lyons]

Put your black meter probe on the ground connection of the battery and the red probe on each of the three pins of the transistor.
When you read each of the voltages make a note of the pins and their voltages ( emitter, bass and collector) .
I would take out the output cap blend and just use the one in the schematic, not much variance to be had there.

John

[Michael]

well

get these readings:

Q1

c = 0,38
b = 0,08
e = 0

Q2

c = 0,25
b = 0,38
e = 0,25

i set the bias (10 k around 8k2)

reversing the wires on the output cap blend (made as described above) doesnt seem to change the readings.

The caps are not of the same make.... but the values are whats important right?

Im puxzzled by this... i wonder if my transistors are down...

Michael

[Michael]

battery was about 8,6 by the way....

[Michael]

collecter value on Q2 seems very low---- compared to what ive read... i gues it should be around 4,5. mine is 0,25!!!!!!!!!!

whats wrong then? can someone deduct that for me?

From what ive read the rest does not seem to far off.

Michael

[R.G.]

It would really, really help us help you if you could post the rest of the info requested in "Debugging Thread: What to do when it doesn't work".

Your voltages indicate that neither of your transistors is working as I'd expect them to. I'd have to see the schematic to know more than that.