I've been changing out the op-amps in a old Hafler D-100 preamp.
Most of the ones I've tried have been jfets and all have worked well with the existing circuit.
But when I inserted a LT1229 bipolar op-amp, I get all kinds of funny noises when turning the volume control toward its minimum position.
After the volume is up slightly, it works as it should from that point on.
After doing some research, my assumption is probably a high DC offset issue that may be increasing as I decrease the volume.
The circuit is a simple non inverting one with Rp(from input to ground) being 274K ohms, R1(from -input to ground) is 1.1K ohms and R2(from output to -input) is 10K ohms.
I tried adding 2.2uF poly caps to the outputs, but that didn't help.
Can someone please tell me how I can get this particular op-amp to work in the circuit I described?
Here's a link the LT1229 data sheet:
http://cds.linear.com/docs/en/datasheet/122930fa.pdf
Thank you...
Most of the ones I've tried have been jfets and all have worked well with the existing circuit.
But when I inserted a LT1229 bipolar op-amp, I get all kinds of funny noises when turning the volume control toward its minimum position.
After the volume is up slightly, it works as it should from that point on.
After doing some research, my assumption is probably a high DC offset issue that may be increasing as I decrease the volume.
The circuit is a simple non inverting one with Rp(from input to ground) being 274K ohms, R1(from -input to ground) is 1.1K ohms and R2(from output to -input) is 10K ohms.
I tried adding 2.2uF poly caps to the outputs, but that didn't help.
Can someone please tell me how I can get this particular op-amp to work in the circuit I described?
Here's a link the LT1229 data sheet:
http://cds.linear.com/docs/en/datasheet/122930fa.pdf
Thank you...