[sdiy] EG

[Scott Gravenhorst]

Apparently it was the lack of coffee.  Sorry, I have the output backwards, it
does go high as soon as it's triggered, so please disregard what I wrote
about the circuit.

music.maker at gte.net wrote:
>I'm a FatMan guy, but this is not the EG used in a FatMan.  But I'll take a
>stab at it.  My $0.02:
>
>When the 555 timer is at rest, i.e., before it is triggered, it's pin 3
>output will be zero volts.  It will not switch to high until the timing
>threshhold is reached.  This means that the 555 pin 3 is holding the control
>(4016 pin 13) for the attack charge current in the off state.  So it's like
>the attack pot which should supply charge current to the integration
>capacitor is not switched in until the attack is already finished.  IMHO,
>there is a design problem here.  Or maybe I haven't had enough coffee...
>
>
>
>
>=?iso-8859-1?Q?=22R=F6nnberg=2C_Niklas=22?= <nikro at itn.liu.se> wrote:
>>Hello!
>>
>>Some days ago I dragged out my old project, the Littleman. It's based on
>>the Paia Fatman VCO and some Tom G circuits. I got some problems with the
>>EG. The Release is working quite ok, and the Sustain to. But I have some
>>serious problem with the Attack. The Attack is working nice for a few
>>seconds after you have turned on the power, but then it doesn't work at
>>all. No changes on the Attack knob makes any changes in the envelope. So
>>when you turn on the synth you can have a short and nice attack time or a
>>slow, but after a few seconds you can't control the attack at all. But then
>>you can make slower attack times using the Decay knob, but I don't want it
>>this way...
>>
>>Can anyone help me out?
>>
>>You can find the schematic here:
>>http://www.itn.liu.se/~nikro/diy/littleman/littleman.pdf
>>
>>Thanks!
>>
>>/Niklas
>>
>
>=========================================================  
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>- That which gets rewarded, gets done.
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>
>-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
>-- Linux Rex         | RedWebMail by RedStarWare
>-- FatMan: home1.GTE.NET/res0658s/FatMan/
>-- NonFatMan: home1.GTE.NET/res0658s/electronics/
>
>

=========================================================  
- A smoking gun is one that's already been fired.
- That which gets rewarded, gets done.
- What good are laws that only lawyers understand?
- Government: The other religion.
- The media's credibility should always be questioned.

-- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
-- Linux Rex         | RedWebMail by RedStarWare
-- FatMan: home1.GTE.NET/res0658s/FatMan/
-- NonFatMan: home1.GTE.NET/res0658s/electronics/