I'm having some issues with my mic preamp. To start from the beginning :
My xlr input is setup as
Pin 1: Ground
Pin 2: Hot
Pin 3: Cold
My xlr is then connected to a electronically balanced input. I'm using a JR 12904 as the op amp. Pin 1 is the output, my hot feeds pin 3,cold to pin 2, pin 4 is grounded and pin 8 is my 18v+ supply. Pins 5, 6 and 7 are not used. My input looks like (https://www.google.com/search?q=op+amp+balanced+input&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwickrev5e7PAhVKQyYKHdKABtUQ_AUICCgB&biw=320&bih=440#imgrc=Z5GfC-fJJcc7lM%3A)
The output of the balanced input then passes through a WIMA film cap, and then enters my preamp stage. (http://darrenyates.com.au/electronics/archives/16)
I used 3.3k resistors instead 2.2k, I used 100k instead of 150k. I used 47uf, 63v electro instead of 22uf. I used a 1000uf 25v electro for one 470uf and a 22uf, 50v electro for the other. My power supply is a 18v+ supply.
I then got rid of the 470uf output cap, and fed the base of a npn with the output. Fed my 18v+ supply to it and I used a 47uf, 63v cap feeding a 1k resistor (cap into resistor, resistor to ground) for my output. As Ian had instructed me for an unbalanced out. My 1/4 connector has pin 1 going to ground and pin 3 is hot.
Here is a couple pictures of my breadboard for help.
Input (https://postimg.org/image/3x5mho94t/)
Preamp stage (https://postimg.org/image/5wk7gulwd/)
Output (https://postimg.org/image/4n0y5clqb/)
https://postimg.org/image/bg0nvyrxv/dbd42ba8/
Transistor 1 is BC547, transistor 2 is BC547 and transistor 3 is BC557. The first BC547 is connected to the BC557 and the BC557 is connected to the 2nd BC547 for the output stage.
Can someone help please?
My xlr input is setup as
Pin 1: Ground
Pin 2: Hot
Pin 3: Cold
My xlr is then connected to a electronically balanced input. I'm using a JR 12904 as the op amp. Pin 1 is the output, my hot feeds pin 3,cold to pin 2, pin 4 is grounded and pin 8 is my 18v+ supply. Pins 5, 6 and 7 are not used. My input looks like (https://www.google.com/search?q=op+amp+balanced+input&prmd=isvn&source=lnms&tbm=isch&sa=X&ved=0ahUKEwickrev5e7PAhVKQyYKHdKABtUQ_AUICCgB&biw=320&bih=440#imgrc=Z5GfC-fJJcc7lM%3A)
The output of the balanced input then passes through a WIMA film cap, and then enters my preamp stage. (http://darrenyates.com.au/electronics/archives/16)
I used 3.3k resistors instead 2.2k, I used 100k instead of 150k. I used 47uf, 63v electro instead of 22uf. I used a 1000uf 25v electro for one 470uf and a 22uf, 50v electro for the other. My power supply is a 18v+ supply.
I then got rid of the 470uf output cap, and fed the base of a npn with the output. Fed my 18v+ supply to it and I used a 47uf, 63v cap feeding a 1k resistor (cap into resistor, resistor to ground) for my output. As Ian had instructed me for an unbalanced out. My 1/4 connector has pin 1 going to ground and pin 3 is hot.
Here is a couple pictures of my breadboard for help.
Input (https://postimg.org/image/3x5mho94t/)
Preamp stage (https://postimg.org/image/5wk7gulwd/)
Output (https://postimg.org/image/4n0y5clqb/)
https://postimg.org/image/bg0nvyrxv/dbd42ba8/
Transistor 1 is BC547, transistor 2 is BC547 and transistor 3 is BC557. The first BC547 is connected to the BC557 and the BC557 is connected to the 2nd BC547 for the output stage.
Can someone help please?