1) There doesn’t seem to be a local off function. I sometimes get MIDI feedback loops. Is there a local off function?
See this post for an in-depth explanation:
2) I feel the triangle LFO could be much slower at the slowest rate. Would be great for slowly evolving textures. I feel that at the slowest rate, it’s still quite fast. Could this be changed? This is really a musical consideration and I wonder why it has been programmed like this.
Range and precision are always a trade off. Since there already is a slow LFO, we wanted to provide a fast one to allow audio range filter modulation.
3) When I engage portamento, with some sounds, there a loud zipper noise. It gets more pronounced in mono mode. I noticed this when playing some high notes with portamento and hearing a low rumble. Slowing the portamento down revealed the zipper noise. I have recordings of this which I can share. It sounds as if the Juno is stepping through all the notes. Is this intended behavior?
The Juno-6 / 60 is DCO based with only a 6 bit DAC. Basically there is only one volume step per note. (If this does not make sense, look up how a DCO works
As we had to work with the existing hardware, a finer resolution was not possible. As a result you can sometimes hear zipper-noise.
4) When I send MIDI notes from my DAW to the Juno66, and the notes are ‘touching each other’ (so a note starts right after the previous has ended) the timing is completely off. I tried different MIDI interfaces, but I always get the same problem. Only when I shorten the notes to not touch each other, the timing is as should. None of my synth do this, not even my SH101 connected by a MIDI to CV converter. The result is very sloppy timing, and I have recordings of this as well that I can share.
The Juno’s envelopes need a relatively long time to reset when gate is off. This ‘dead’ time needs to be added by the Juno-66 (and is also added by the original cpu) to ensure proper envelope re-triggering. When playing via midi, this is more noticeable because you expect better timing.
There is little we can do to improve this, it is a problem of the analogue hardware.
5) The filter envelope is quite slow compared to the Juno envelope. As such, I find it for instance unusable when creating bass sounds, with fast VCA en VCF envelope attacks. The juno66 envelope is always too late. It’s probably a digital envelope and I know the Juno60 envelopes are renowned for being fast. So I can understand. But it’s not only that. I also find the Juno66 envelope very ‘unmusical’. For instance, if I use it to make percussive sounds (attack 0, sustain 0, release short and change the decay), the curve of the decay never seems to work. It’s either too long or too short. Could this be changed? I feel that right now, it’s technically a fine envelope, but part of extending the synth should have been musical consideration. Just as I almost know for sure that the Roland engineers went to great lengths with the Juno60 to fine tune all the fader ranges, envelope curves, etc. To me it’s the difference I feel for instance between the Arturia Minibrute (very unmusical ranges and curves) and the Moog Sub37 (very musical).
This is difficult to answer because this is also a matter of taste. It will however not be possible to make it any faster.
6) I can’t get the S/H LFO to sync, At least not from the Stereoping controller. I think I tried to do it from the keyboard as well, but that didn’t work either. (not in my studio right now) Is this a known bug?
No, usually works well