While there are other names for this mod it seems the most common is the “Paul C” mod, so we’ll use that for this discussion. I also like to keep things simple for the benefit of the most people as well so instead of the technical aspects of what’s happening in the circuit, let’s look at what it actually offers the player.
The 5E3 is known for very it’s early volume increase & break-up, so at about 3 you are at full on overdrive with about max volume and everything after that is just more drive and saturation. It’s also known for having a fairly loose bottom end. The interactive nature of the controls let you dial in some great clean tones though, so it’s more of a tone chameleon than folks would think. The Paul C mod will give you more headroom so the overdrive wouldn’t come into play until you are at about 6-7 (tweeds go to 12), but after that it’s overdrive as normal. It also gives you more of a traditional volume increase instead of that very early ramp up, the tone control acts more like a traditional tone control, and the bottom end gets tightened up as well as getting a giving you a bump in volume.
I was also asked about whether it was possible to make the “Paul C” mod a switchable option for the 5E3 D-Lux. Since that was a one time request I didn’t pursue it at the time for that customer but I did put it down on my project list as I’ve found that good ideas often come thru the questions asked by folks. Well, it’s turn finally came up and I must say it was timely as another request for that mod came in, so I committed to the build and started to work out the details.
The mod could be done with “flying” the added components but a new circuit board layout would be a much neater way. After a bit of calculation for the layout I was ready to proceed and since I also have Garolite & fiber board in bulk material making the new circuit board wasn’t difficult at all. The switchable “Paul C” mod is a nice fit inside the chassis and the mini-toggle for it is tucked away next to a pre-amp tube.
Playing two 5E3 D-Lux amps side by side, one stock & one with the mod, can give you a good comparison of what the mod offers and it may be somewhat dramatic. The drawback to that comparison is that it doesn’t take into account the rest of the components in each amp like the cap & resistor values, tubes, or speakers and they all contribute to the tone of the amp. With the switch on the other hand you get an accurate comparison and while it may seem a lot more subtle it’s still noticeable. Having the option can be advantageous as it does open up some new possibilities.