That is how I have my PSIM setup now. It works fine for the most part.
Since we are spinning a new board, I think it would be useful to have full synthesizer style
inputs. That is algebraic summing with offset and span for each channel. Plus calibratable
voltage inputs, so you can compute in real floating point voltages and interface 1 volt per
octave keyboards.
It is just one TL072 per channel, or two TL074s instead of one. The cost impact is minimal
compared to the DAC cost.
I have a 36 dB per ocatave reconstruction filter for the Speakjet 1, it sounds better than
the one given in the app notes. I was hoping the Speakjet 2 would be out by now, it was
supposed to have ADSRs in it.
--- In ComputerVoltageSources@yahoogroups.com, "djbrow54" <davebr@...> wrote:
>
> --- In ComputerVoltageSources@yahoogroups.com, "john mahoney"
> <jmahoney@> wrote:
> > I like the way this is shaping up:
> > Input attenuators, yes!
>
> Mine are not input attenuators. They are 0 - 10 volt controls sourced
> from a regulator and normalled to the inputs. With no input plug the
> controls provide 0 to 10 volts. With an input plug, the controls are
> disconnected and there is no attenuation
>
> > A SpeakJet option would be fabulous
>
> I haven't really done much with my SpeakJet. I did just buy the
> TTS256 to play with. I do use a general pin to interface to the
> SpeakJet. Interrupts have to be disabled to send data using the
> serial commands. I also used the buffer half full flag instead of
> speaking flag to speed things up by using the buffer. However, you
> can't effectively put pauses in with program delays since you don't
> know when the chip is speaking. You have to program in the pauses. In
> retrospect I might have used the speaking flag but this all changes
> when using the TTS256.
>
> > Dave, I assume that you mean MOTM horizontal units when you refer to
> 1U and 2U. (BTW, the 0.5U MOTM format was recently born on the MOTM
> list.
>
> Yes
>
> > > Just spent some time on the phone with John Loffink discussing ...
> > What's a "phone"? ;-)
>
> It took me a bit to remember how to dial long distance :)
>
> > > I'm waiting for someone to suggest FOCAL. Anyone here that old?
> > > Probably could still write it.
> > Don't know that one. We had a FOCUS programmer in our department
> > once, but I assume that it's something else.
>
> Focal was a PDP-8 high level programming language where commands were
> single character. Pretty efficient. ALso did PL/M for any old-timers
> out there. See http://en.wikipedia.org/wiki/FOCAL
>
> Dave
>