Crackling noise?

Started by radioheadftw, June 18, 2008, 11:27:32 PM

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radioheadftw

I built another FF this time with NTE158 transistors...
Bypass works fine, when I turn the effect on all I hear is crackling.
What are some debugging tips?

Tonepad schematic was used.

kurtlives

Crackling or buzz?

Crackling usually means some DC signal is getting through the pedal...

Go through the debugging process....schem, voltages, layout, mods, etc...
My DIY site:
www.pdfelectronics.com

radioheadftw

It's a crackling-ish noise, no buzz, but it kinda crackles.
Transistor is dead?
How would I measure if my transistors work or not?
After that I'll go into the other measurements, voltage, continuity, etc.

kurtlives

Transistors usually don't "die". It is easier to destroy germanium transistors with heat though. Did you socket?

On RG Keen's site (geofx) there is an article about testing transistors.
My DIY site:
www.pdfelectronics.com

radioheadftw

No, no socket.
I might have burned them out, since they are Ge.

R.G.

Most of the time, crackling is an intermittent contact, not a dead transistor. Not that it couldn't be a transistor, but I'd look for bad solder joints, cracked PCB traces and broken component leads first. if it were mine.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.