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DIY Stompboxes => Building your own stompbox => Topic started by: jflam on December 26, 2003, 08:05:05 PM

Title: Jh2 fuzz face
Post by: jflam on December 26, 2003, 08:05:05 PM
This is my first time building a pedal. I chose this particular one because it SEEMED like an easier job.  I tried two seperate attempt, neither of which yielded any good results.  I've followed all the debugging steps provided on this site (except for the audio probe) and everything appears to have checked out fine, however, I have had no luck.  It plays in the bypass state.  In the effected state, there is a loud hum and you can hear the guitar only at a loud volume, but there is no distortion.  CAN ANYONE HELP ME???!! :(
Title: What kind of transistors are you using?
Post by: petemoore on December 26, 2003, 08:42:06 PM
IIRC the JH 2 is a neg ground Silicon transistor FF.
 I always trimpot or socket Q2's collector resistor position
fir a Fuzz Face    or   [[ Tonebender> [Q3's collector]], many schematcs [try some links, Runoff Groove has examples] have this trimpot/.
 I also debug the ckt before adding bypass or putting it in a box.
 Take some voltage measurements and post them
 clip One DMM lead to ground, the other DMM lead checking voltages from ground at Q1 and Q2's collectors  bases and emitters.
Title: Voltage values
Post by: jflam on December 27, 2003, 02:23:56 PM
My transister values are as follows:

Q1:C -2.41; B -1.79; E -0
Q2:C -2.98; B -2.38; E -.521

question:  I was checking my voltage values around the whole circuit (grounding one lead and testing components) and i was getting a 0 readout for my FX in and surrounding components.  Is this right?