Author Topic: Vibratone debug...  (Read 813 times)


Vibratone debug...
« on: February 17, 2009, 07:11:19 PM »
Hey everyone, I have been trying to debug this for a couple days, cant seem to find the problem, Im posting hoping someone could help!
So first of all Im using a great John Lyons PCB, checked for cold solders, solder shorts and everything is clean and conducting. I have audio probed it an past Q1, I get some sort of faint signal that is sort of stuttering very fast, that could be explained by the voltages I posted below. So am I wrong or should all Jfet Q's should have at least 4.5 volts in to "open"?

Here are the voltages and Q types:

Q1 2N-5952   D: 8.97v  G: 4.55v   S: 3.22v                                      Q7   2N 5088       C 4.82          B:.60(mv)           E .40(mv)
Q2     "          D: 4.71    G: 2.82    S:1.48                                         Q8       "             C:8.97          B:4.84                E: 4.31
Q3     "          D: 5.09    G:2.56     S:1.43                                        Q9        "             C:6.67          B:2.77                E: 2.30
Q4    "           D: 8.97    G: 4.44    S:3.36                                         Q10 2N 3906       C:8.97          B:8.31               E: 9.07
Q5    "           D:1.16     G: 1.16    S:-(minus) 72.7
Q6    "           D: 1.16     G1.16      S-(minus) .49mv

thanks for the help
Builds so far....Neovibe,Ge FFace, Ge Rangemaster, Bigg Muff Tri, Bigg Muff Green Russian,Highway 89,Heartthrob tremolo,Ruby amp,Tube screamer mods,Vox Wha mods, pedalboard using a Yamaha keyboard bottom.