Hi, I have a Ring Mod and a Phaser… I play Guitar, Bass, and Little Phatty… And I wanted to know what Moogerfooger to get next. I play in a Rock band, but at home I play Jazz Fusion, Funk, Rock etc. I am considering either the Freqbox or the Lowpass Filter. I really like the sounds that you can get using freqbox through bass or a Bass Preset on the LP. I also like the sounds you can get with bass or guitar through the Lowpass Filter. One problem is I can’t find a good demo on the Lowpass Filter on youtube with guitar so… As I understand the Freqbox is kinda hard to dial in a good sound? I am willing to learn how to use it so that doesn’t bother me. If anyone could tell me what other sounds you can get on the Lowpass Filter besides Auto-Wah, it will be much appreciated. 
Thanks,
Derek
the low-pass filter is immensely useful. The Freqbox is great IMO to add a second oscillator to something like the Micromoog or the ARP Axxe, or other functions where an oscillator or additional envelope follower are wanted. The 2-pole setting works really well with guitars. You will probably like using the sine LFO from one of your other Foogers to control the cut-off of the filter. The CP-251 is a great device to combine with the filter, as is an expression pedal.
Try to find a Bass Murf. Those are just too funky, especially with Bass.
Although expensive, my choice would be the Delay. (Was the first Fooger I bought.) But then, I’ve always used a delay on my bass since the first time I heard ‘One of these days’. What a good delay does to your playing is wonder to behold.
The LPF could be fun, but I would definately want an EP-2 to help control it.
As much as I love the lowpass filter I would suggest the freqbox because you can use the envelope out to trigger the the filter in the little phatty. So then you have your lowpass filter with the added benefit of modulation, overdrive and full adsr…of corse if you use your phatty and guitar at the same time that won’t work to well
lowpass and freqbox are both great! The wah wah is just one of the things you can get from 101.
Good demos showing really many possibilities of the effects are
mf-101 http://www.youtube.com/watch?v=dBc6bJsycCk
mf-107 http://www.youtube.com/watch?v=6VgQ-p3p1tI
MF-104Z; definately.