Ok, I'm kind of addressing my own question, but wanted to put this out there for people to find and hopefully find helpful. I looked through lots of info and didn't find a one-stop solution for the quirks of this very nice bass di. This is a review/troubleshoot in one post. I hope it proves helpful.
1. This is a nice little DI it is going to be on par with other solutions in it's price range. I think the overall quality of what it can bring to the table is on par with what you would or could expect from something like a Zoom brand pedal.
2. As of the writing of this post, the most current firmware update is v 4.0
Melvin Lee Davis Bass Preamp + DI (NBP-5) - NUX (nuxefx.com)
As the link above ages, the info in it will change (or it will break and you'll just have to search for what you want manually). As of right now, you can find firmware version 4.0 amongst the things you can download from NUX at the bottom of the page. For me, no problem was created by updating to firmware 4.0. Others have. YMMV.
I'm using a windows 10 PC, so can't address anything MAC.
If you are having problems getting your pedal to connect to the NUX software, or to update, you may be told to turn off the power to the pedal for 5 seconds, unplug the USB for 5 seconds. Reboot your computer. Try a different cable. All good ideas.
Here is what I found to be the most effective:
1. download the firmware update program, unzip it and get it ready to use.
2. pull the power wire to the pedal so it doesn't get any power.
3. Make sure the USB cable is plugged into the PC and your pedal.
4. Hold down BOTH pedal switches at the same time. WHILE holding down both switches, plug in the power wire.
5. If you were successful, you should have two blinking lights on the pedal; one green and one red. - ALSO, the firmware update software should NOT be complaining about being able to see your pedal. It shold say something like pedal found, or pedal connected.
6. Unless you need to update the firmware on your MLD Preamp Pedal, you can back out of the firmware update program WITHOUTH actually doing the update and return your pedal to regular service. This "tricks" the pedal into connecting. At this point, your regular MLD program should be working and let you do the fun stuff, like pick which pedal amp model you want, cab sim etc.
Here are two third party IRs that are worth getting.
Shift Line Bass IR Pack (shift-line.com)
Select "download the bass IR pack".
Dr Bonkers In This Together™ Almost Free Cab Pack IR Collection – Dr. Bonkers Soundlab LLC™ (drbonkerssoundlab.com)
It's buck $1 and well worth it.
I found that the IRs that ship on the pedal are just too boomy and didn't have the bones to make up a good punchy tone. Again this is my personal taste, so YMMV.
My fav. out of the bunch is the Sunn model in the shift line offering, but I also found the 1x10 and 1x12 IRs in the Dr. Bonkers package to be nice as well. Well worth the $1.
Couple more pointers:
1. You can over-write the IRs that come with the pedal. If you have your software set to one of the positions (1 - 8) and you upload a new IR it will over-write it.
2. If you just want the HPF LPF with no IR, leave a blank spot and select it. No cab sim will be included, but you will get the ability to adjust HPF/LPF and get that benefit.
3. The MLD Pedal likes Mono 48/24 IRs. Others may work, but (for the 3rd time in this post) YMMV.
This pedal does a lot, so if you want to completely immerse yourself in the rabbit hole, you will likely find many things that are useful. I did not address MIDI, but I know it has MIDI function. I'm just not using it in that capacity. It also has facility to connect to DAW and probably other things as well.
For me, my goal was just to have a good-value compact DI for my simple pedal board that included AUX IN and Headphone OUT to facilitate connection to IEM. I wanted a pre-post for the DI out. And most importantly I needed it be able to provide useful/usable tone. It's a good value and I recommend it highly, as long as you are willing to put up with all of the above, which, once you get it under control, it's really that big of a deal. Atl least to me the way I'm using it.
