So, I've got this Mangler together and when I set the bias using the test points on the board I get +4.5 v with the black lead from the DMM on the test pad and the red lead to ground. Unless I am misunderstanding the process, (which is entirely possible), this should be negative 4.5 v, correct? I am using the "Fuzz Face PNP, US" transistors from smallbear, and used their supplied resistors (with the exception of R-3 which I kept according the the Madbean schematic along with the 20k bias trimmer). I'll take some voltage readings later today on the transistors and post them here, along with some photos. I've checked the battery leads and they are correctly hooked-up (+ to ground, - to 9v-), hit all the solder joints again and checked the polarity of my caps, all OK. Any thoughts before I upload some photos? Thanks, Dave
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#2
General Questions / Add tone stack to Mangler?
September 11, 2013, 02:37:47 PM
Greetings all, I want to add a "Big Muff" style 2 pot tone control circuit to my Mangler build. Would I just connect the "out" line from the Mangler board to the "in" side of the tone circuit and then continue out of the tone circuit to the amp? Dave.
#3
General Questions / Strange (to me) Cherrybomb problem
July 08, 2013, 01:12:04 PM
Greetings all,
Just completed my Cherrybomb build and am having a strange problem. When I power the pedal on all is fine and it sounds great, for about 5 - 10 seconds. Then it goes into the fuzzy / fizzy / distorted mode I think I've read about on these boards. I've changed transistors, no difference. Here are some specifics on the pedal, maybe someone can point me in a direction. I've already re-flowed all the solder joints (3) times so I don't think it's that.
Input voltage at battery - 8.8v (tried another battery at 9.6v, no change).
I used an electrolytic cap for C-1 with the minus side to output (tried the other way, no change).
I used a 4-position switch for the gain control with 33k, 50k, 81k and 1k resistors on the outputs (tried removing this and using a 5k trimpot, no change).
Transistors - Q1 and Q2 - 2n2222, Q3 - 2n3904 (tried Q1 and Q3 - 2n3904, Q2 - 2n2222, no change).
Voltage at the transistors are:
Q1
C - 1.38
B - .30
E - .06
Q2
C - .80
B - 1.37
E - .73
Q3
C - 5.42
B - 1.5
E - .88
From scanning these boards it seems the only one in range is Q3. Any ideas on where to look first (or second, or third...). Thanks, Dave.
Just completed my Cherrybomb build and am having a strange problem. When I power the pedal on all is fine and it sounds great, for about 5 - 10 seconds. Then it goes into the fuzzy / fizzy / distorted mode I think I've read about on these boards. I've changed transistors, no difference. Here are some specifics on the pedal, maybe someone can point me in a direction. I've already re-flowed all the solder joints (3) times so I don't think it's that.
Input voltage at battery - 8.8v (tried another battery at 9.6v, no change).
I used an electrolytic cap for C-1 with the minus side to output (tried the other way, no change).
I used a 4-position switch for the gain control with 33k, 50k, 81k and 1k resistors on the outputs (tried removing this and using a 5k trimpot, no change).
Transistors - Q1 and Q2 - 2n2222, Q3 - 2n3904 (tried Q1 and Q3 - 2n3904, Q2 - 2n2222, no change).
Voltage at the transistors are:
Q1
C - 1.38
B - .30
E - .06
Q2
C - .80
B - 1.37
E - .73
Q3
C - 5.42
B - 1.5
E - .88
From scanning these boards it seems the only one in range is Q3. Any ideas on where to look first (or second, or third...). Thanks, Dave.
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