Beiträge von raigan

  • USB 2 Hardware Upgrade

    I think that some people here are getting quite confused for no reason -- USB 2.0 is a specification which involves MANY parts, one of which is **support** for a higher maximum speed. See this for more details: http://en.wikipedia.org/wiki/Universal_Serial_Bus#USB_2.0


    So in light of the above spec, it's should be no great mystery how a device can support USB 2.0 while not supporting speeds above 12MBit/s: the spec clearly shows that "USB 2.0 supports up to 480MBit/s".


    Both the "supports" and the "up to" language make it quite obvious that the transfer rate being specified is a maximum, not a minimum, and furthermore this maximum speed is merely supported -- not required.


    Nowhere in the spec does it **require** 480MBps in order for devices to be certified as 2.0 compatible. There are many differences from USB 1.0 to 2.0 beyond transfer speed, however they may not be as easy to understand or as obvious to users.


    If you care about transfer speed, look at the specific speed labeling -- Low/Full/High is what matters, not the protocol version #. If it says "High Speed" then 480MBps is indeed required, otherwise it's not.


    Definitely the spec and terminology could be a bit less confusing, but it's not some inscrutable mystery beyond comprehension!


    Having said that, it seems like Firewire would be a better choice over USB, sadly for some reason it was overlooked :(

  • Improved resolution/granularity of parameters

    First of all, after using the hell out of my A for almost 10 years, I finally got a TI; thanks for making such awesome products. :)


    The only thing that hasn't been improved from A to TI is a way to circumvent the limits of MIDI in order to provide a more fine-grained resolution for parameter values; the current granularity of some parameters is a bit frustrating.


    Example: LFO1->Osc Pitch modulation is far too coarse to dial in accurate semitone modulations. For chiptune-type sounds, it would be quite useful if I could have LFO1 set to square and modulating Osc Pitch by +/- 6, 12, 18, 24, etc. semitones, so that the osc pitch would jump between octaves.


    Unfortunately, this isn't possible because of the current discretization; the closest setting of LFO1->Osc Pitch is +/- 68.8, which will _almost_ produce a +/- 6 semitone jump, but it sounds slightly off (not quite a perfect octave), and more importantly the resulting notes don't fall on exact semitone values, they're off by maybe 40-50 cents. This means that such an effect can't be used on Osc1 since there's no way to bring it back into tune (as there are only semitone-increments for patch pitch adjustment, no cents), this type of modulation can only be used with Osc2 using detune to bring the pitch back onto exact semitone values. And using the Mod Matrix or Osc2 Assign to modulate osc pitch is even worse, the granularity is super-coarse.


    For the specific case of LFO1->Osc Pitch, you might implement a "semitone" mode (similar to how LFO clock can be either free or BPM-sync'd) so that amounts are quantized to semitone values. But this is more than likely a waste of resources since it's a big change for a small/specific effect.



    A better solution would be to add some sort of generally applicable fine-tune solution which could be applied to any parameter. For many parameters it would be *QUITE* useful to be able to dial in a more precise value, since when you only have 127 values to use, the actual value you want is often impossible to select because it lies between one of the 127 selectable values.


    One possible implementation would be to add a "fine tune" parameter which spanned the range between adjacent values of the "coarse" (current) parameter. For instance, each adjacent LFO1->Osc1 Pitch value jumps by 1.5-1.6%; a fine-tune knob would let users add a value between 0% and 1.6% so that the space between values on the main knob is covered. Basically, each parameter would be represented as a 7.7 fixed-point number rather than simply a 7bit integer. I hope this makes sense :)


    Since such a change is likely to be quite involved, a simpler alternative would be to add a range of "Constant" modulation sources to the Mod Matrix. These would function similar to the "Random" source, except that they would add a constant value to the destination rather than a random value; the reason that multiple "Constant" sources might be useful is that there could be a range of magnitudes, i.e Constant01 would produce values in [-0.1,+0.1] while Constant1 would produce values in [-1,+1], Constant10 would produce [-10,+10], etc. This seems more or less trivial to implement, but it would make a *huge* difference for anyone who's struggling with the current resolution of some parameters.


    Thanks for your time :)

  • Osc 1 pitch drifting

    I have a patch where Osc1 will eventually start playing quite flat, by a semitone or more, for no clear reason.


    To reproduce this:
    -start with an init patch (plain sawtooth)
    -set Osc Balance: -100; Initial Phase: 1
    -set LFO2 Assign Target: Osc1 Pitch, Amt: 0%
    -set LFO2 Rate: 111, Shape: Square, Contour: +44, Mode: Mono, Trigger Phase: 1
    -set LFO1 Rate: 81, Shape: Saw, Contour: +47, Mode: Mono, Env Mode: On
    -set Matrix Slot 1: Source: LFO1, Amt: +12, Dest: LFO2 Assign Amt


    After a while, the pitch of osc1 will be flat. I'm not sure if this is caused by waiting for a while or playing notes, but after a minute of playing it's noticeably flat (you can use osc balance to compare w/ osc2). Changing to a different patch and back resets the pitch.


    I'm not sure why this is happening; I've tried to ensure that all Oscs and LFOs are reset with each note rather than being free-running, so it's not clear what could be causing this.


    Is it a bug, or am I just doing something stupid?
    Thanks for your time :)