For my first project, decided to build this active direct box:
http://sound.westhost.com/project35.htm
and have a couple of basic questions. The one I'm building is the battery operated one at the very bottom.
First, can I substitute a 10uF cap for the 1uF input coupling cap? Everything I've read seems to indicate that close is close enough.
Second, I've built a steel box to house the circuit in. I'm assuming I should ground the case to something. Should that be the -ve or the 0 volt line (going into pin 5 of opamp)?
Also, if anyone is inclined, can you explain what is happening.
Here's what I think is happening. The general idea is that the audio in is split and sent out to the XLR where, if one line is positive, the other is neg and visa versa. This allows any interference to be removed by the mixer circuit. Also, because of the low output impedence of the opamp, the output is low impedence. What I'm not clear on is how the signal is being inverted to go to pin 3, since the input is being fed into the non-inverting input 5. And, since the top opamp is using unity gain, wouldn't it be a different voltage level then the bottom one, which has some feedback? A general explination would be very helpful.
Thanks,
Ziller (a newbe)
http://sound.westhost.com/project35.htm
and have a couple of basic questions. The one I'm building is the battery operated one at the very bottom.
First, can I substitute a 10uF cap for the 1uF input coupling cap? Everything I've read seems to indicate that close is close enough.
Second, I've built a steel box to house the circuit in. I'm assuming I should ground the case to something. Should that be the -ve or the 0 volt line (going into pin 5 of opamp)?
Also, if anyone is inclined, can you explain what is happening.
Here's what I think is happening. The general idea is that the audio in is split and sent out to the XLR where, if one line is positive, the other is neg and visa versa. This allows any interference to be removed by the mixer circuit. Also, because of the low output impedence of the opamp, the output is low impedence. What I'm not clear on is how the signal is being inverted to go to pin 3, since the input is being fed into the non-inverting input 5. And, since the top opamp is using unity gain, wouldn't it be a different voltage level then the bottom one, which has some feedback? A general explination would be very helpful.
Thanks,
Ziller (a newbe)