eh là bas ma
Well-known member
Hello,
I would like to have your opinion on something.
I built this version from a musikding's kit :
It distorts at some settings unless i turn Threshold above 12', so there is obviously something wrong.
As I looked for anything suspicious I noticed something real strange...
Both R10 pads are showing continuity with E, B and C. One R10 side reads 4.57 V, the other 1.117 V From the schematic I didn't expect both R10 pads to be connected with all transistor's pads...
I have also continuity between D4 negative side, one R10 pad (the one at 4.57 V) and both R11 pads, I wouldn't expect that either.
But this is what puzzles me the most : these connections happen only when the DC power jack is inserted.
If I unplugg the power jack, connections are as shown in schematics, no more strange continuities...
I can't see any explanation for this...of course I reflowed, checked for shorts, nothing I can find, and without the BC237 transistors, the same behavior happens with sockets too.
Here are my readings :
DC 9V+ = 9.50 V
BC327
E= 4.60 V
B= 4.19 V
c= 1.122 V
TL74 ACN
1= 4.62 V 14 = 4.61 V
2= 4.61 V 13 = 4.62 V
3= 4.36 V 12= 4.15 V
4= 9.23 V 11= 0 V
5= 4.37 V 10= 4.42 V this pin 10 follows the voltage at C3/R5 junction, depending on the Release setting.
6= 4.62 V 9= 4.62 V
7= 4.63 V 8= 4.19 V
LM13700N
1= 1.120 V 16= 0 V
2= 0.6 V 15= 0.8 V
3= 4.62 V 14= 0.5 V
4= 4.62 V 13= 0.6 V
5= 4.62 V 12= 0.7 V
6= 0 V 11= 9.23 V
7= 0 V 10= 0 V
8= 0.5 V 9= 0.650 V
My question is : What do you think about these connections happening only when DC 9V power jack is plugged ?
Could it be correct by any chance ?
Thanks for your help !
I would like to have your opinion on something.
I built this version from a musikding's kit :
It distorts at some settings unless i turn Threshold above 12', so there is obviously something wrong.
As I looked for anything suspicious I noticed something real strange...
Both R10 pads are showing continuity with E, B and C. One R10 side reads 4.57 V, the other 1.117 V From the schematic I didn't expect both R10 pads to be connected with all transistor's pads...
I have also continuity between D4 negative side, one R10 pad (the one at 4.57 V) and both R11 pads, I wouldn't expect that either.
But this is what puzzles me the most : these connections happen only when the DC power jack is inserted.
If I unplugg the power jack, connections are as shown in schematics, no more strange continuities...
I can't see any explanation for this...of course I reflowed, checked for shorts, nothing I can find, and without the BC237 transistors, the same behavior happens with sockets too.
Here are my readings :
DC 9V+ = 9.50 V
BC327
E= 4.60 V
B= 4.19 V
c= 1.122 V
TL74 ACN
1= 4.62 V 14 = 4.61 V
2= 4.61 V 13 = 4.62 V
3= 4.36 V 12= 4.15 V
4= 9.23 V 11= 0 V
5= 4.37 V 10= 4.42 V this pin 10 follows the voltage at C3/R5 junction, depending on the Release setting.
6= 4.62 V 9= 4.62 V
7= 4.63 V 8= 4.19 V
LM13700N
1= 1.120 V 16= 0 V
2= 0.6 V 15= 0.8 V
3= 4.62 V 14= 0.5 V
4= 4.62 V 13= 0.6 V
5= 4.62 V 12= 0.7 V
6= 0 V 11= 9.23 V
7= 0 V 10= 0 V
8= 0.5 V 9= 0.650 V
My question is : What do you think about these connections happening only when DC 9V power jack is plugged ?
Could it be correct by any chance ?
Thanks for your help !
Last edited: