I recently set up my Les Paul with series/parallel push-pull pots. I switched it over from coil splits to test it out. I noticed with both setups, switching to either a split coil or parallel has a noticeable decrease in volume on a clean channel. With the neck pickup in parallel, I've noticed that some strings, particularly the A and D strings are really hard to hear. An example would be Love Me Two Times by The Doors - bouncing around that E chord is really hard to hear. Is this normal? It's like they get scooped out. The low E is more audible and the treble side is clear. And I'm not sure if my mind is playing tricks on me, but it seems that the neck pickup in series is more muddy now. I don't think I damaged anything and the connections are good. No cold solder joints that I can see. I'm using a Duncan Jazz neck and JB bridge. I like the bridge in parallel, but the neck seems really scooped. I also have 50's wiring with independent volume controls for what it's worth.