Seventh Circle Audio

I recently fleshed out my SCA rack with 2 additional J99 channels. After assembly I tested all the channels and realized that channels 3-8 were very quiet, but channels 1 and 2 (the ones closest to the power supply) had some noise. This was not hum, but more of a power supply buzz. Channel 1 was the worst. The problem was most notable with dynamic mics and gain above 6.

I solved the problem by purchasing a sheet of Mu-Metal on eBay (~$25)and making a hood over the power supply. No more noise!

btw, I have the chassis with the Mu-Metal shield.

I hope this helps anoyone else with a similar problem.