[sdiy] papareil Dual lin ADSR

[harrybissell]

I looked up the EnvyLope... and there is some mention on Aron's
site about an LED problem. Maybe it still exists.

If you look at the resistors associated with the LEDs... in one case I
see
a 470 ohm resistor. If you added a 100 ohms in series (putting the
resistor
in place of 'self' adds a resistor in series with everything :^)....

...you introduce an error of 20%.  Not to mention that any change in
power supply voltage after the resistor is seen EVERYWHERE in the
circuit.

Its like running your circuit on dead batteries... literally. Power
supply
impedance should be low.

Ten ohms might not be the magic number, just a suggestion.  I'd really
try
the inductor. It would have DC resistance of probably a few milliohms...
and
much higher AC impedance. So it would be more effective at decoupling
the power supply.

The inductor and the capacitor after it... might also resonate at some
frequency
and make the problem worse.

Its a tough choice...

H^) harry

Frédéric Bourgeais wrote:
> 
> Oops, sorry, a "self" is an inductor in french :=)
> 
> I'll try 10 ohm/100µF. But before adding these 100 Ohm, led fashed very low.
> thanks for your advise.
> 
> ++Fred
> 
> Le 19 janv. 06, à 18:13, Harry Bissell Jr a écrit :
> 
>      Sounds like a power supply problem.
> 
>      The 'self' (don't know what he means by that) is shown as
>      an inductor. These typically have a very low resistance...
>      MUCH lower than 100 ohms.
> 
>      You might try like 10 ohms... and make the capacitors after that
>      100uF or larger.
> 
>      If they will fit... maybe a 100uH inductor (choke) in place of the
>      'self' would be better.
> 
>      If someone knows what 'self' means let me know
> 
>      H^) harry
> 
>      Frédéric Bourgeais <fred at upian.com> wrote:
>      Hello all,
> 
>      I built 2 year ago Marc Bareille's dual lin ADSR which is based on
>      Aaron Cram's Envylope
>      http://m.bareille.free.fr/modular1/adsr/mb_cvadsr2.htm
> 
>      As my modular grow, I had to repackage it, I did some tweaks.
>      To prevent noise, I added 2 100 ohm resistor where Marc used Self, to
>      prevent PSU noise (I used links before).
>      I also changed the 8 Led to smaller ones (5mm to 3mm).
> 
>      Now, the A,D and R led don't flash anymore. But previous 5 mm led
>      flashed very very low.
>      Which resistor should I change to provide more current for a nice
>      effect ?
> 
>      I also noticed some oscillations problems between the 2 enveloppes (
>      kind of secret, but annoying LFO feature ; ))
> 
>      Any builder experienced theses troubles ?
>      Thanks for your help
> 
>      ++Fred