Hi Bob, just picked up a Marantz 3800. It has a few issues, it pops when i power it on. So i have been powering off the amp first and get noise in the left channel speaker after about 5 seconds? The tuner switch also has a buzz when pressed and the eq button has static when pressed. How much would it cost roughly to refurbish this preamp and would you be interested in doing it? Thanks for your time, Mike