Okay, i've seen lots of people asking about upgrading their kingstons and what-not. I don't know how many people have done it, but I just did, and here's what happened. First of all, here's the skinny. Replaced the MM bridge pickup with a Bart Musicman 72MM5C pickup. Installed a Bart HR3.4 preamp (Vol/Vol; Mid P/P; Bass/Treble). Sounds great! Very warm and complex Mid's minus the harsh mid's that the Heir5 originally had. Here's what happened. Spoke to Mike Tobias on the phone. He said there was a Bart model that would be a drop-in replacement. I forget what model number it was, but when I gave the info to Grasshopper at Bass Central, he said that Mike was mistaken because the quoted model number was a Soapbar pickup. Hmm... ok, well, anybody can make a mistake. So I asked Grasshopper to order me whatever would be the correct replacement pickup. He suggested the MM5 and ordered it, along with the preamp, and said it would take 3 to 10 days depending on whether it was in stock, etc. It took 21 working days, but that's ok. I figure some people have to wait even longer. But when i did get the pickup, IT DIDN'T FIT. Not even close. Huge gaps on each side (length-wise). Considered returning it, but did some research online and came to the conclusion that there is NO direct replacement for the KIngston/Heir Bridge pickup. No matter what Mike Tobias or Grasshopper say. (unless you somehow get one from lakland, etc.) That, plus Grasshopper saying that it was me that ordered the wrong part and there would be a 20% restocking fee... helped persuade me to keep it and figure something out. Well, I always wanted a wooden pickup cover... I guess I'll make one! So, now to install the thing. Against my better judgement, I went to Marsmusic in Duluth. There is an older guy there who seems like he'd be a seasoned veteran luthier (never judge a man by his age or appearance - lesson learned). He told me no problem... he's installed "dozens of barts", he's been "doing this for years," etc. Well, when he was done, i played it through a Hartke rig there, (an amp that i'm totally unfamiliar with). Also, the store was very very noisy. It sounded OK, but was very noisy. Also, the relative volumes of the pickups (individually and when blended) was very uneven. He told me that the neck single-coil pickup, being passive and inherently noisy was just being amplified by the hot preamp. OK, makes sense, i guess. Regarding the volume issue, he said that I would need to pay him to do a setup to adjust pickup height, etc. Yeah, whatever... I took it home, and after careful listening, figured out that there was OBVIOUSLY a phasing problem with the pickups. Plus it was really noisy. I decided to open the thing up, and armed with the wiring diagrams, dove in to my first experience wiring an active preamp. Bartolini makes things easy because the HR3.4 is a pre-wired harness. I mean, what was I thinking paying some guy at Marsmusic $50/hr to do this? And how in the hell did they mess this up???? Oh, I should mention here that Bartolini did not include a HR3.4-specific diagram. Rather it seemed to be a generic diagram for the 918 preamp circuit that they probably use for their various preamps. I think this is lame. If you pay $160 for a preamp, you should get very very specific instructions. I know I probably should have stopped when I first opened the package and called Bartolini, but oh well... I didn't feel like faxing them and then waiting around for an answer... Back to the installation... It was fairly easy to switch the hot and ground wires from the neck-single-coil pickup. And careful examination showed me that the ground wiring was not right either. After about an hour of trying this and that with the ground wires, bingo... got it right. So, after all that, the verdict? It sounds nice. The passive electronics tone is gone, but it has a more hi-fi and rounded tone with deeper bass. The mids are very warm. And like I mentioned earlier, the original harshness and very aggressive mid-range that the bass originally had - gone. But if you keep the original pickups, and add a bart preamp, I'd highly recommend getting the AP active-passive option so you can always go back to the original sound anytime. I didn't go that route because i went with Bart pickups that I feel work better with an active preamp. I'm going to install a Basslines Stack Jazz in the neck position tomorrow, and that should improve things further (and No Hum). The original neck pickup is actually nice, i think, but doesn't really work that well with the additional headroom from this preamp. So what did i learn from this ordeal? 1. Some guitar repair guys can't get a simple preamp installation right even with a pre-wired harness. 2. Don't spend $$$ on pickups without being absolutely sure that you are getting what you absolutely want. 3. The Bartolini HR3.4 and MM pickup combo sounds very nice and anyone out there wanting to upgrade their Kingston/Heir should do it~ So, can anybody offer some advice on building a wooden pickup cover?