I guess it all boils down to what type of sound you think fits your type of music. I'm not tiring of 12tet necessarily, moreso it's the use of obvious chords and scales that get me thinking, 'oh no, it's those intervals again'. I don't look to Jazz as a way out of that as I don't think it fits my idea of what I like, I'm quite liking the feel of sustained tension and unresolved dissonance in music, the more I play with dissonance, the more my ears seem to adjust to it more than I did when I first started experimenting with that sort of thing.
It's chords that I have found ( to an extent ) that have me uninspired, I know this thread is based on that but a lot of the time I'm leaning towards contrapuntal harmony. The use of counterpoint to create a harmonic structure has me thinking it's a much more less obvious way to approach things and you do effectively create chords, just that they are by the individual parts when they fall together and don't feel like a progression or like there's an immediately noticable chord structure.. Anyway, that's separate from this thread, I was just replying to the 12tet thing.
Maybe you are already thinking the right way with tone clusters, if it's less obvious a chord structure you want when using fixed intervals, I'd be looking down that sort of line. I guess any scale can quickly become cliche'd, I must admit though, when using a series of diminished chords or even just the tritone, it's all too easy to end up with the same sort of music as you might have done the other week. There's not a huge scope of experimentation ( at least not that I can see ) if you are thinking diatonically.
What about Augmented chords? 4 semitones + 4 semitones and then by using say the whole tone scale, you'd have 6 diatonic chords. Say you were in 'C': C/D/E/Gb/Ab/Bb could all have an augmented chord built on them. I'm not sure how a track built of pure Aug chords would sound but to be honest, it's the sort of thing I do like to try, just to get a different sound when I tire of something I have been doing previously.
Out of interest, is it possible on the Voyager to use say a square wave LFO to change the semitone pitch of an oscillator? I was just wondering, if it was, you could get some alteration on the 3rds ( or whatever ) in really interesting ways.
I quite like your idea of 4ths, well, or 5ths actually. Like detune +7 and -7 semitones, like a C, G and an F in the lower octave. Doesn't sound like a sus4 chord like that, plus it's neutral and it's going to work on a lot of the scale degrees diatonically in say a typical natural minor scale for example. Well actually, having said that, you'd get an 'A' and a 'Db' on the 'D' and 'Ab' respectively.