Loading ...
Sorry, an error occurred while loading the content.

AW: [Doepfer_a100] Soft Sync on A111

Expand Messages
  • Dieter Doepfer
    ... VCOs. No. The hard and soft sync inputs have no additional circuits but are connected directly to the corresponding sockets of the A-111. Only pull down
    Message 1 of 12 , Feb 7, 2005
    • 0 Attachment
      > -----Urspr√ľngliche Nachricht-----
      > Von: Josue Arias [mailto:josue.arias@...]
      > Gesendet: Sonntag, 6. Februar 2005 12:59
      > An: Doepfer_a100@yahoogroups.com
      > Betreff: Re: [Doepfer_a100] Soft Sync on A111
      >
      >
      >
      > Hi Florian,
      >
      > You are wrong about the A111...The A111 uses a CEM 3340 but the module
      > is not a raw CEM module, it have circuits around the sync inputs,
      > comparators I think so it needs to see a rising or falling edge as all
      VCOs.

      No. The hard and soft sync inputs have no additional circuits but are
      connected directly to the corresponding sockets of the A-111. Only pull down
      resistors (if no signal is connected to the sockets) and z-diodes for input
      protection/voltage limitation are used.

      Best wishes
      Dieter Doepfer
    • Florian Anwander
      I have to correct myself ... That s nonsense: The Zener Diode is of course for limiting the incoming signal (I mismatched this in my brain with a sentence from
      Message 2 of 12 , Feb 7, 2005
      • 0 Attachment
        I have to correct myself

        > a zener diode for eleminating positive signals
        That's nonsense: The Zener Diode is of course for limiting the incoming
        signal (I mismatched this in my brain with a sentence from another text,
        which suggested to insert a normal diode, that blocks the positive part
        of syncing signals).

        Florian
      • Josue Arias
        Yes, I`ll try a short inverted pulse but why wasting an inverter? the resistor and diode ARE there for driving the sync with a saw wave! The good about the
        Message 3 of 12 , Feb 7, 2005
        • 0 Attachment
          Yes, I`ll try a short inverted pulse but why wasting an inverter? the
          resistor and diode ARE there for driving the sync with a saw wave!

          The good about the modulars is that you can end doing the same
          operation using several approaches! :)

          Best Regards,

          Josue.







          > > You can check the Manual.
          > The schematic of the A111 shows the blank input for the Pin 9 of the
          > CEM3340 (only additions are a pull down resistor and a zener diode for
          > eleminating positive signals (schemo see page 1 of the service manual
          > and explanation page 7). So beside of the zenerdiode and the pulldown,
          > the Softsync input is designed as suggested in the datasheet.
          >
          > The Datasheet says for this connection on page 6:
          > "[...]Finally, the oscillator may be soft synchronized by negative
          > pulses applied to the threshold voltage pin (pin 9 of 3340[...]). These
          > pulses cause the triangle upper peak to reverse direction prematurely,
          > causing the oscillation period to be an integral multiple of the pulse
          > periode. [...]"
          >
          > So according to the Doepfer schematics, the Curtis datasheet and - as
          > minor argument - to my experience, a simple short pulse is perfect to be
          > used as soft syncs master signal. Of course a saw will do something
          > similar, but that shouldn't prevent you to try a pulse. ;-)
          >
          > Florian
        • Florian Anwander
          Hi Josue ... Hmmm, could you explain why? Florian (always interested in deepening his electronic skills)
          Message 4 of 12 , Feb 7, 2005
          • 0 Attachment
            Hi Josue

            > Yes, I`ll try a short inverted pulse but why wasting an inverter? the
            > resistor and diode ARE there for driving the sync with a saw wave!
            Hmmm, could you explain why?

            Florian (always interested in deepening his electronic skills)
          Your message has been successfully submitted and would be delivered to recipients shortly.