That much revered single-space rack-mount preamp.
This one's got a bent front panel near the right side rack ear, and missing the grommet around the power-on button.
Nevertheless it works fine and sounds a beauty.
No issues (the second photo is not the same PB-1, but it's the same model.
At a casual glance your never see a marked difference between them.
Or hear any).
$150 plus the cost of getting it to you from 02917.
Continental 48... more pics to come...