Mbira
Well-known member
Hi folks,
I got this really cheap buffer with these VU meters I picked up on Amazon. I'm planning on using a Sifam for my project, but I wanted to experiment with this first.
There is a "high" and a "low" input that you can feed the buffer (unbalanced).
They hid what the IC is. Here is what the schematic is:
I'm wanting to put the VU at this point in the circuit (I want to switch between seeing gain after gain knob and gain on the output XLR):
As most of you know, I'm really new at trying to do anything beyond just "paint-by-numbers" of following a schematic.
The Buffer works fine when I put it on the output XLR, but when i put it in this stage it sucks up about 90% of the gain. I'm guessing the issue is that it has a 2K input resistor while the following stage (the output knob) is 47K. So I'm thinking that I'd really want a really high value resistor going in to my op amp. Is that correct? Like...I want it as high as it can go and still work, right?
So-assuming I'm correct (and I'm probably not), how do I figure out what opamp I can use and the highest value of resistor I can put there?
To be clear-i was just testing with this buffer, and I'm planning on rolling my own (with a known op amp).
I got this really cheap buffer with these VU meters I picked up on Amazon. I'm planning on using a Sifam for my project, but I wanted to experiment with this first.
There is a "high" and a "low" input that you can feed the buffer (unbalanced).
They hid what the IC is. Here is what the schematic is:
I'm wanting to put the VU at this point in the circuit (I want to switch between seeing gain after gain knob and gain on the output XLR):
As most of you know, I'm really new at trying to do anything beyond just "paint-by-numbers" of following a schematic.
The Buffer works fine when I put it on the output XLR, but when i put it in this stage it sucks up about 90% of the gain. I'm guessing the issue is that it has a 2K input resistor while the following stage (the output knob) is 47K. So I'm thinking that I'd really want a really high value resistor going in to my op amp. Is that correct? Like...I want it as high as it can go and still work, right?
So-assuming I'm correct (and I'm probably not), how do I figure out what opamp I can use and the highest value of resistor I can put there?
To be clear-i was just testing with this buffer, and I'm planning on rolling my own (with a known op amp).