Re: [LAU] Connie, an organ template for JACK

From: Nick Copeland <nickycopeland@email-addr-hidden>
Date: Mon Jun 01 2009 - 12:00:59 EEST

> Looking at the schematics there is no evidence of any
> 'click removal' action. Also the waveforms summed there
> (for 4',8' and 16') would not be sinewaves. Each divider
> output has an RC lowpass filter before going to the mix
> bus. Assuming the dividers generate square waves, the
> smoothest waveform you can get would be a triangular one.
> What each of these RC filters does exactly will depend on
> the impedance it sees on the mix bus, and this is a complex
> function of the drawbar positions (*all* of them for each
> bus, since they share the resistors) and the number of
> notes already on.

Nice information.

I never got to hook my Continentals up to a scope to have a good look at them but I agree the sines were not all that pure so a tri would be possibly closer to the original than a sine waveformed lookup table as used by Connie. I might actually give this a test in bristol and see how its Vox sounds with them, it also uses similar lookup tables. It would not be that difficult to fill them with heavily RC filtered square waves, even testing with some different slew rates and see what effect that has.

Your comments on the drawbar effects are very interesting, I had never considered the Vox to have damping as the Hammond did but I would definately believe it. Do you happen to know if the schematics were from a Mark-I Jennings design? I would be interested in modeling some of the resistor circuits as well.

Regards, Nick

_________________________________________________________________
Windows Live™: Keep your life in sync. Check it out!
http://windowslive.com/explore?ocid=TXT_TAGLM_WL_t1_allup_explore_012009

_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
Received on Mon Jun 1 12:15:02 2009

This archive was generated by hypermail 2.1.8 : Mon Jun 01 2009 - 12:15:02 EEST