Potato Cakes
Well-known member
Hello,
I'm working on a couple of preamp/EQs and while doing initial testing I thought I was having an issue with the noise floor, but it turns out there was an impedance mismatch between the generator (line level) and the preamp. When I connect a microphone or my battery powered handheld generator I do not have this issue. I have selectable H-pad installed to allow the preamp to handle line level signals so I can use the EQ for mixing, but this won't do me much good currently as the noise level with the impedance mismatch is the same regardless of the pad being in or out. So I'm wondering is there a different type of pad that could be implemented which would also address the impedance/noise issue? I'm working within the parameters of the existing board and design, so essentially I have to be able to do this with the existing DPDT switch that I am currently using for the pad. I know that this can be done at the input transformer and a number of other ways if I was building this out as a new project, but this would require more alterations to the board and metal work than I am willing to do for these particular preamps.
Thanks!
Paul
I'm working on a couple of preamp/EQs and while doing initial testing I thought I was having an issue with the noise floor, but it turns out there was an impedance mismatch between the generator (line level) and the preamp. When I connect a microphone or my battery powered handheld generator I do not have this issue. I have selectable H-pad installed to allow the preamp to handle line level signals so I can use the EQ for mixing, but this won't do me much good currently as the noise level with the impedance mismatch is the same regardless of the pad being in or out. So I'm wondering is there a different type of pad that could be implemented which would also address the impedance/noise issue? I'm working within the parameters of the existing board and design, so essentially I have to be able to do this with the existing DPDT switch that I am currently using for the pad. I know that this can be done at the input transformer and a number of other ways if I was building this out as a new project, but this would require more alterations to the board and metal work than I am willing to do for these particular preamps.
Thanks!
Paul