Guitar Pedal Fault Diagnosing - Signal Generator Test Tone

Using a signal generator test tone in conjunction with an audio probe to help fault diagnose a guitar pedal circuit

[jordywhitmer]

I have a student building guitar pedals. Is there anything special for the headphone cable connecting the phone to the 1/4" phono plug? Isn't the audio level out from a phone too high compared to the signal a guitar would produce?

[DiyguitarpedalsAu]

definitely an good idea and something i've meant to do for a long time. That said i've only ever had one 'incident'. Testing a delay pedal that feedback very quickly and volume was on a moderate amount. Kinda hurt.

[RebelBluesman]

a good test amplifier is a radio shack mini amplifier/speaker at radio shack for $14.00. You can make a test probe from a finishing nail and a .01uf /400volt, capacitor, a 6' mono audio cable with 1/8' male input for radio shack mini amp. and strip the wires on the other end and Soilder the center wire to one leg of the  capacitor and the other leg of cap to the nail  and heat shrink end and cover in heat shrink, this prevents dc voltage from entering your  radio shack mini amp next take the bare wire or ground wire and soilder to alligator clip testing lead and strip the end and soilder to ground or bare wire and heat shrink. Leave the other end to the clip for grounging  .Now plug into iPhone or ipad and into amp for signal and use mini amp for sound volume to hear probeing, it has a volume control. clip grounding clip to chassis and your set.