It's easy to see that this is a limited interest topic. However, for those that may be interested now or in the future, I wanted to update the thread. I have finished my experiment and am very pleased with the results.
To start with, I bought a shorter scale, 4 string bass. Two reasons for this: I knew that the best and most flexible installation of the Roland GK-3B pickup requires screws and I didn't want to permanently alter any of my existing basses. Additionally, I knew that I wanted to be able to play chords for certain sounds and the closer fret spacing would be welcome. The bass I bought was a short scale SX J Bass: http://amzn.com/B000BY5H3K
I chose this model based on a neat piccolo bass video I saw on YouTube: http://www.youtube.com/watch?v=ljwKdwuCniQ
I installed the Roland GK-3B Divided Pickup for bass on the SX J Bass using Roland's installation instructions. Keep in mind that Roland specifically warns against using piccolo strings on page 6 of the GK-3B Owner's Manual:
"Do not use the GK-3B on basses with doubled strings or other highly customized basses, piccolo basses and other basses with unusual tunings, or basses with other non-metallic core strings. The pickup may not function properly in such cases."
Duly warned, I trod onward.
Since the GK-3B can be used with 5 and 6 string basses as well, there are different ways to install it. I placed it so that it was right in the middle of the strings below the bridge pickup. The B string and C string pickups hang out on either side of E-A-D-G. I left the original bass strings on the instrument for the original pickup installation and alignment.
With the bass back together, I plugged it into my GR-20 Guitar Synthesizer. I chose this unit for cost and simplicity. Using a GI-20 GK-MIDI Interface and an external synthesizer can prove tricky, however the GR-20 is designed with ease of use (e.g., live music) in mind and has everything you need in a single, stomp box unit. I followed the GR-20 instructions for setting string sensitivity (a critical step), then put the unit (with version 2.0 software) in bass mode and started playing.
It worked! However, the famous delay problem was present. I had expected it. The lower I played, the more perceptible the delay between plucking a note and hearing the result was. It's something you could work around and learn to live with, however not what I had in mind.
After I verified that everything was working, I removed the original bass strings and installed D'Addario piccolo bass strings, which are: http://daddariostrings.com/DADProduc...&ProductId=120
After installation, I checked the intonation, truss rod and string height from the divided pickup and made adjustments as necessary. When I was done, I had a piccolo bass. Really, a big guitar minus the high B and E strings.
(An aside: a piccolo bass is fun! Familiar lines have a whole new sound. The new sound inspires you to play differently and go in different directions as well. Remember that you have a whole new instrument to enjoy on its own merits. For example, guitar effects that don't work so well on bass are now in scope. What about an EH POG for an instant 8 or 12 string bass or a Line 6 M13 for sounds undiscovered? Not today, though—we have more to do.)
Back to the GR-20. I again followed the instructions for setting string sensitivity and put the unit in guitar mode this time.
It worked wonderfully well. All notes on all strings play; no odd note cutoffs as I had been warned might happen. With the frequencies doubled thanks to the piccolo bass strings, the tracking delay halved. The tracking is great now. With the GR-20 in guitar mode, all of the voices sound as you would expect them to, from pianos to organs to basses to guitars to strings to flutes and beyond.
One caveat, which I imagine is true for all divided pickup users: you need to carefully adjust the height of the divided pickup, string sensitivity on the synth (as previously noted) and also a parameter Roland calls "Play Feel" on the GR-20. Play Feel can be adjusted on a per-patch basis, anything from extreme sensitivity to tap technique to no dynamics at all (like an organ). Certain patches greatly benefit from a different Play Feel setting and experience will help you figure this out.
So, to summarize:
- I have access to sounds I'd only dreamed of
- I have a piccolo bass
- I don't have a regular bass when I use it (However, this can be a Pro with the large variety of bass sounds available in the MIDI universe and the extra guitar effects processing now available for the piccolo bass.)
Not everyone is interested in this type of thing. However, if you're adventurous and your bandmates will give you the space, it might be just what you've been looking for. Roland has put more R&D into strings driving MIDI and the good things that can come from that than any other company, along with constant support and good products. It's not absolutely perfect, but it's very, very good.
It worked for me and I thought I'd share it with you.