modding a boss bd-2 went wrong

[synner88tc]

ok so i was modding my boss blues driver with a combination of mods i have found. most of the changes were replacing crappy capacitors with better quality, though a few values were changed.

i added a "phat" switch (switch between 0.22uf and 0.033uf on c101) i also added a 1uf cap between the source of q10 and one side of r29 on a switch for a
octave fuzz mod. everything tested great no problems at all. even sounded fantastic.

i made 3 more changes, and when i tested it nothing, well if i crank the amp i can hear the signal coming through slightly.

c10 - 1uf
r50 - 100 ohms
r36 - 47k

now i was working from a schematic and a mod sheet that as i found through debugging was incorrect the change to r36 was supposed to effect the pre-clipping
tone stack but the change was intended for r38. the schematic had r36 labelled in both places!

so the change to r36 is a bad mod.

r36 (4.7k) takes the source from both q13 and q14 to ground.


ok so i know what i did wrong, i have replaced r50 and r36 with the stock values. i have used an audio probe to trace through the circuit i get sound
all the way to the gate of q13 and then nothing. q13 is a k184. i took a k184 from my other fully working bd-2 and replaced q13 still nothing, i took
the assumed dead k184 that i pulled and put it in the good one and it still works fine. 

so what could have been damaged by up sizing that resistor by a factor of 10?

power supply - 9.11v

q13 (k184)

drain - 8.34v
gate - 0v
source - 4.77

q14 (k184)

drain - 8.32v
gate - 3.79v
source - 4.77




http://www.freeinfosociety.com/electronics/schemview.php?id=116   

[bunnycat]

Hi - I was doing similar mods to my BD-2 the other day and ended up with exactly the same, as in "could only hear the signal when the amp was completely cranked".  Did you ever figure out what happened?

Samantha