A couple of days ago, we posted about one of the 2 TAB U373a compressor modules we had just received at the tech shop. Read that post here. That particular unit was about 1000 serial numbers apart from the other we received. This might not sound like a big difference, but keep in mind they made very few of these sought-after compressors. You’ll notice that the layout of the PCB and component arrangement is much more neat with almost no visible connections. All the components to component wiring seen on the earlier units has been traced on the circuit board or eliminated due to component repositioning. Next, we’ll see if they sound the same! Stay tuned.