Hi Ryan + all,
I'm interested in using it at/over flanger-like frequency (less than a millisecond)
This would allow to play with analog physical modelling if the freq of the delay is voltage
controllable and we can achieve very short delays...
Great that you are experimenting with it!
I suppose that apart from filters, some kind of dynamic processing (compression/
expansion) would help to get a cleaner signal...
Best wishes,
Fernando
Ryan Williams <destrukto@g...> wrote:
I'm interested in using it at/over flanger-like frequency (less than a millisecond)
This would allow to play with analog physical modelling if the freq of the delay is voltage
controllable and we can achieve very short delays...
Great that you are experimenting with it!
I suppose that apart from filters, some kind of dynamic processing (compression/
expansion) would help to get a cleaner signal...
Best wishes,
Fernando
Ryan Williams <destrukto@g...> wrote:
> Fernando wrote:
> > Great and exciting news, thank you! 16kHz it's very good I think.
> >
> > What's the minimum delay time (approx.) that you can get at max clock freq?
> >
> > Fernando
>
> hi Fernando,
>
> I don't really have a good method of measuring exactly how short the
> delay can be. Currently I plan on having a switch that selects either
> the 64k or 256k ram which will be labeled short and long modes. If you
> clock the chip too fast, it gets all messed up and starts spitting out
> garbage (I have no idea if this could damage the chip, but it hasn't
> yet). I will probably setup some kind of trimmer so that I'll be able to
> adjust the CV input of the 4046 to allow a maximum clock frequency
> slightly less that the PT2395 will accept.
>
> For the moment, I'm using the resistor values on the 4046 that Ken had
> labeled on the development board. the capacitor for the 4046 is a 33pF.
> This doesn't allow the shortest or longests delays that I want with a CV
> range of 0-5V. My guess is that it currently gives around 50ms-80ms in
> 64k/short mode. when sending it a sound from an envelope that has very
> short attack and decay you can hear the echo still. I know this can be
> improved quite a bit because in my first version, I couldn't hear the
> echo. This part of the circuit is what I'll be working on just as soon
> as final exams are over in school...
>
> another note about the LTC1063 filters. They add several parts to the
> circuit. Running of +-7.5V (which is the maximum allowed). I use two
> adjustable regulators LM337L and LM317L. several additional bypass
> capacitors are needed to keep the noise down on the LTC1063s. A opamp
> buffer is also needed between the delay output and the output filter's
> input. Thats the only way, I could figure out how to get rid of the DC
> offset from the delay IC. A capacitor alone wasn't working...