kylewetton
Active member
Here's what I have so far, as you can tell I'm still very much learning
Have a couple questions about this idea I'm breadboarding (BMP into an active EQ)
- Thread starter kylewetton
- Start date
Chuck D. Bones
Circuit Wizard
That's all good except I would ditch C10. It's not needed and could cause IC2.2 to oscillate. I don't think it's causing the bias problem. You have measured all 8 pins on IC2?
They should be:
1: 4.5V
2: 4.5V
3: 4.5V
4: 0V
5: 4.5V
6: 4.5V
7: 4.5V
8: 9V
You're sure the IC is plugged in correctly? No bent pins and proper orientation? We've all screwed this up at one time or another.
They should be:
1: 4.5V
2: 4.5V
3: 4.5V
4: 0V
5: 4.5V
6: 4.5V
7: 4.5V
8: 9V
You're sure the IC is plugged in correctly? No bent pins and proper orientation? We've all screwed this up at one time or another.
kylewetton
Active member
It's all plugged in pretty tightly, here's what I'm getting
1 8.7v
2 8.6V
3 8.5V
4 0V
5 4.6v
6 4.6V
7 8.6V
8 9.2V
But be worth trying a different IC
Chuck D. Bones
Circuit Wizard
Pins 6 & 7 are supposed to be connected together, so why are their voltages different? Look for missing connections. I think the IC is fine and you made a mistake. Let's see a photo of your breadboard.
kylewetton
Active member
I just pulled the IC and replaced it with another one and the values are now the same as yours, i replaced the other IC in and back to incorrect values, then new one again, same as yours, thanks for helping me out with this!
Chuck D. Bones
Circuit Wizard
Hmmm. I wonder how that IC got damaged...
The important thing is it's working now.
You're putting the variable gain stage (U2B and associated parts from your BvF sch) to the left of C12 and after the BMP, right?
The important thing is it's working now.
You're putting the variable gain stage (U2B and associated parts from your BvF sch) to the left of C12 and after the BMP, right?
kylewetton
Active member
Hmmm nah at the moment it’s just Q1 - Q3 of the big muff straight into C12, so I just have the one IC, level is now the volume out right at the output. How dumb am I being? Should I bring back a buffer?
I tried just swapping out the tone network between IC1 pin 7 and back into IC2 1 and 2, basically exactly what Tone Job did with the input and output buffers except rewired the three pots with their correct values etc, the EQ doesn't really affect the tone much though, not as much as wiring it up with Q1-Q3 straight into the second half of the Angry Charlie (the one we debugged), which sounded a lot more responsive
