From Jason Proctor Sent Sun, Sep 29th 2019, 23:37
From Jason Proctor Sent Sun, Sep 29th 2019, 23:37
Negative 1v/oct doesn't imply any thru-zero behaviour. It just makes the pitch lower, all the way to LFO territory and from there... depends on your VCO interpretation. Also IIRC if you're thru-zero FMing a VCO you should use the linear FM input rather than the expo one. 1v/oct is just a subclass of a regular voltage range, one that is interpreted a particular way by appropriate - which so far we have constrained to VCOs and oscillating VCFs. "Octave" is a description of pitch, after all. Once again may we ask the OP what he had in mind about other types of inputs interpreting 1v/oct? On Sun, Sep 29, 2019 at 3:24 PM Brian Willoughby <xxxxxx@xxxxxxxxxxxx.xxx> wrote: > > The original question was, =E2=80=9CWhy isn=E2=80=99t everything 1V/oct?= =E2=80=9D > > The answer is, =E2=80=9CBecause everything is CV, and CV includes 1V/oct = as well as anything else you might need.=E2=80=9D > > CV is generic, and Quincas did a great job of summarizing many variations= . > > 1V/oct is just a very specific subset of CV, and even 1V/oct can vary, so= it=E2=80=99s not necessarily compatible across all synths. Some VCO module= s will accept negative 1V/oct, and those are =E2=80=9Cthrough-zero=E2=80=9D= VCO modules. Some VCO modules are limited to 5V, so they can only handle 5= octaves of range with a single control. Other VCO modules can accept 10V, = so they might be able to handle 10 octaves of range, but the accuracy might= suffer at the extreme ranges unless it=E2=80=99s a very expensive VCO. > > All of these synths that apply a 1V/oct source to a VCA or ADSR are scali= ng the CV to a usable range, and thus it ceases to be 1V/oct after it has b= een scaled (see Quincas=E2=80=99 comments about math and other CV processor= s). > > > The Sequential Circuits Pro-One has a Keyboard Amount knob in the VCF sec= tion, and it is incredibly difficult to tune that to 1V/octave. On my Pro-O= ne, the calibrated setting falls at about the 70% point on that knob. Below= or above that position, it=E2=80=99s no longer 1V/octave. I usually do not= let guests touch the Keyboard Amount knob! ;-) > > The Prophet 5 has a switch to add Keyboard to the VCF, and it=E2=80=99s s= urely 1V/octave. > > Some famous synth that I=E2=80=99ve used many times, but do not own (so I= forgot which one it is), has a 3-way switch for VCF keyboard tracking, wit= h Off, Half, and Full as options. When set to =E2=80=9CHalf=E2=80=9D it wor= ks out to be 500mV/octave. > > > In the last three examples, even the VCF, which can actually interpret oc= taves, does not always use 1V/octave when applying keyboard CV to the Cutof= f. As soon as you apply 1V/octave to a VCA or ADSR, you will surely need to= scale the CV to something other than the 1V/octave starting point. Once yo= u scale, it doesn=E2=80=99t really matter whether the CV started out as 1V/= octave or not (unless you have a digital synth where the math is precise an= d repeatable across varying temperatures). > > Brian Willoughby > > > On Sep 29, 2019, at 10:36 AM, Jason Proctor <xxxxx@xxxxxxx.xxx> wrote: > > Well of course, but that's true of any voltage. The point is that the > > level input has no way of interpreting a 1v/oct protocol in the way > > that an exponential pitch input does. > > > > On Sun, Sep 29, 2019 at 10:31 AM DJ Maytag <xxxxxxxx@xxxxxxxx.xxx> wrot= e: > >> > >> You could route 1V/oct to the Dual ADSR=E2=80=99s level controls. The = higher the pitch, the stronger the effect of the envelope. > >> > >> ________________________________ > >> From: Jason Proctor <xxxxx@xxxxxxx.xxx> > >> > >> I don't see any mention of 1v/oct in the Dual ADSR docs. The level > >> input is a linear input to the output VCA. Some looping envelopes have > >> 1v/oct inputs to use them as VCOs, but although the Dual ADSR does > >> loop, it doesn't have any CV control of envelope timings. > >> > >> Perhaps OP can give us some indication of what he might expect from > >> 1v/oct on inputs other than exponential VCO/VCF etc? > >> > >> On Sun, Sep 29, 2019 at 8:34 AM DJ Maytag <xxxxxxxx@xxxxxxxx.xxx> wrot= e: > >>> > >>> I=E2=80=99m pretty sure that=E2=80=99s 1V/oct modulating ENV amount a= nd/or timing, as I mentioned. Now that I think of it, I think there=E2=80= =99s an input to Intellijel=E2=80=99s Dual ADSR that could be used to scale= the ADSR intensity by sending it 1V/oct. > >>> > >>> ________________________________ > >>> From: John Emond <xxx.xxx@xxxxxx.xxx> > >>> Sent: Sunday, September 29, 2019 10:21 AM > >>> To: Quincas Moreira > >>> Cc: DJ Maytag; Tristan; Dustin Sedlacek; Analog Heaven > >>> Subject: Re: [AH] Why isnt everything 1 v/o ? > >>> > >>> What about Keyfollow on the Jupiter 8 envelopes? > >>> > >>> Cheers, > >>> > >>> John > >>> > >>> On Sep 29, 2019, at 9:17 AM, Quincas Moreira <xxxxxxx@xxxxx.xxx> wrot= e: > >>> > >>> 1v/oct is a standard for tuning pitches. That makes sense in exponent= ial inputs of VCOs and VCFs, everything else is simply measured in voltages= , and sometimes the response curve, like log, lin or expo. In my experience= most cv outputs in eurorack 10vpp, being 0 to 10v if positiv only, and -5 = to +5 if bipolar, though there are plenty that output double that (-10 to 1= 0). Inputs often can be set to respond linearly or log/expo and often go th= rough attenuverters. And a system is never complete without utilities for c= onditioning voltages to what you need. I have quite a few voltage processor= s myself which I use for attenuation, inversion, offset, amplification, mix= ing etc... > >>> > >>> Sent from my iPad > >>> > >>> On Sep 29, 2019, at 12:09 AM, DJ Maytag <xxxxxxxx@xxxxxxxx.xxx> wrote= : > >>> > >>> The only use I could see for a 1V/oct input on a VCA is if you want s= ome intentional bleed/droning as you play higher up on the keyboard. > >>> > >>> The second use wouldn=E2=80=99t be on the VCA itself, but on an envel= ope/ADSR controlling a VCA. The higher the pitch, the shorter the overall e= nvelope timing. > >>> > >>> ________________________________ > >>> From: Tristan <xx@xxxxxxxxx.xxx.xx> > >>> > >>> I presume by 1 v/o you mean 1 volt per octave. While this makes sense= for oscillator or filter cutoff > >>> frequency it does not necessarily make sense for a VCA or other modul= e without a common unit of > >>> calibration. A VCA could have a logarithmic, linear or other non-line= ar control law for the gain. To calibrate > >>> a logarithmic control to 1V/6dB gives a gain range of 60dB over the t= ypical 0-10V control source range > >>> which is not adequate to fully cut off the sound. To allow for this a= VCA will often have a voltage mixer for > >>> the input control voltages to allow them to be scaled to the desired = control depth. > >>> > >>> /Tristan > >>> > >>> On Sun, Sep 29th, 2019 at 10:29 AM, Dustin Sedlacek <dustin.sedlacek@= gmail.com> wrote: > >>>> Every time I talk to eurorack guys about 1 v/o VCA or wavefolder the= y don't > >>>> seem to understand why anyone would want that. > >>>> > >>>> Isnt control the thing that everyone wants? > >>>> > >>>> What about 1v/o inputs are not desirable? Is their something I am no= t > >>>> understanding? > >>>> > >>> > >