I had a Coda Fet 02b preamp about 20 years ago which I bought directly from Coda since they had a large number of circuit boards on hand after the model was discontinued so they did a limited manufacturing run to use the spare inventory up. They were selling them for just under 50% of the original list price.
When I received it there was on input selection which made a noise when I switched to it. I called Coda up and complained and the tech told me it was most likely an impedance miss match between the cables and the preamp input. So I swapped the cable to a different input selection and the noise followed it. After I replaced the cable the sound disappeared and I used that preamp for over 12 years.
When I received it there was on input selection which made a noise when I switched to it. I called Coda up and complained and the tech told me it was most likely an impedance miss match between the cables and the preamp input. So I swapped the cable to a different input selection and the noise followed it. After I replaced the cable the sound disappeared and I used that preamp for over 12 years.