Ah I see thanks Dieter; it took a few reads but I think I understand! Regards, Neil Sent from my iPhone > On 12 Sep 2016, at 13:42, yahoo@doepfer.de [Doepfer_a100] <Doepfer_a100@yahoogroups.com> wrote: > > The drop to zero is not the important thing (except for LFO applications > where the modulation can stop and continue again when the linear control is > turned up again). But the linear frequency bias/offset is important because > the linear FM is different when the bias/offset gets lower. Usually VCOs > even with a linear FM input have no linear frequency control. The internal > circuit of the VCO multiplies the shares of the linear and exponential > section to define the VCO frequency. Without the manual linear frequency > control the linear share (without linear FM) has a fixed value which is > typically near at it's maximum. A linear FM with e.g. 1 Vpp applied to the > circuit is totally different compared to a situation with e.g. half the > linear frequency bias/offset. With the LF control you are able to control > the linear FM much better than without this feature. The standard VCO > situation of the A-111-2 is with LF control fully CW (i.e. the linear share > near to maximum). > > Best wishes > Dieter Doepfer > > >> -----Ursprüngliche Nachricht----- >> Von: Doepfer_a100@yahoogroups.com [mailto:Doepfer_a100@yahoogroups.com] >> Gesendet: Donnerstag, 8. September 2016 22:00 >> An: Doepfer_a100@yahoogroups.com >> Betreff: Re: AW: [Doepfer_a100] A-111-2 question >> >> >> >> >> >> Thanks Dieter, >> >> >> Can I ask what the application of a manual drop to zero is? >> >> >> Neil >> >> Sent from my iPhone >> >> On 8 Sep 2016, at 18:56, yahoo@doepfer.de [Doepfer_a100] >> <Doepfer_a100@yahoogroups.com> wrote: >> >> >> >> The A-111-2 has no thru-zero feature but only a manual control and a CV >> input for linear frequency adjustment/modulation. With all controls at >> minimum the oscillation nearly stops (typ. 1Hz in VCO mode). But we are >> working on a thru zero version of the A-111-2 (probably named >> A-111-4). But >> it's too early to publish any details as the circuit is a bit more >> complicated. It's based on a suggestion by Doug Curtis in his documents we >> obtained while we were the European distributor for the Curtis >> chips in the >> the eighties. The circuit is similar to the CEM3340 based thru zero VCO by >> Juergen Haible but with a few more features (like zero point modulation). >> >> Best wishes >> Dieter Doepfer >> >>> Hi people, >>> >>> Does anyone know if the new VCO has thru zero capability? It >>> looks like it from the LF control being able to go to 0 but there >>> isn't specify mention. >>> >>> Neil > > > > ------------------------------------ > > ------------------------------------ > > > ------------------------------------ > > Yahoo Groups Links > > >
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Re: AW: AW: [Doepfer_a100] A-111-2 question
2016-09-14 by Neil Kagan
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