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DIY Stompboxes => Building your own stompbox => Topic started by: nguitar12 on May 22, 2015, 01:58:15 AM

Title: Replaceing LFO circuit for little angel chorus.
Post by: nguitar12 on May 22, 2015, 01:58:15 AM
Hi everyone recently I want to replace the LFO circuit for my little angel chorus.
I feed the pin 3 of the 555 circuit to pin 2 of pt2399 but it doesn't working.
Can someone please suggest  possible explanation to this?
Title: Re: Replaceing LFO circuit for little angel chorus.
Post by: anchovie on May 22, 2015, 06:50:06 AM
Which 555 circuit? Does it work on its own?
Title: Re: Replaceing LFO circuit for little angel chorus.
Post by: samhay on May 22, 2015, 07:29:32 AM
>Hi everyone recently I want to replace the LFO circuit for my little angel chorus.

Why?
Title: Re: Replaceing LFO circuit for little angel chorus.
Post by: nguitar12 on May 22, 2015, 07:46:23 AM
Quote from: anchovie on May 22, 2015, 06:50:06 AM
Which 555 circuit? Does it work on its own?

Yes i attached a led and it will flash. I measure with the voltmeter and I can see the voltage swing from 0 to 9v.
Title: Re: Replaceing LFO circuit for little angel chorus.
Post by: nguitar12 on May 22, 2015, 07:47:28 AM
Quote from: samhay on May 22, 2015, 07:29:32 AM
>Hi everyone recently I want to replace the LFO circuit for my little angel chorus.

Why?

I want to modified the waveform. Original doesn't sound very smooth to me.
Title: Re: Replaceing LFO circuit for little angel chorus.
Post by: samhay on May 22, 2015, 10:47:52 AM
The LFO in the Little Angel should output a triangle(ish) waveform. I don't think you will do better (smoother) with a 555. The way the LFO modulates the PT2399 Vref is probably what you don't like.

How are you connecting the 555 to the PT2399? - a (partial) schematic would be useful.

Title: Re: Replaceing LFO circuit for little angel chorus.
Post by: nguitar12 on May 22, 2015, 11:22:32 AM
Quote from: samhay on May 22, 2015, 10:47:52 AM
The LFO in the Little Angel should output a triangle(ish) waveform. I don't think you will do better (smoother) with a 555. The way the LFO modulates the PT2399 Vref is probably what you don't like.

How are you connecting the 555 to the PT2399? - a (partial) schematic would be useful.

http://www.circuitdiagram.org/images/triangle-wave-generator-using-555.gif

I am connecting the output of 555 to the negative terminal of 10uf electrolytic cap  at pin 2 of the depth pot.
I don't think Little Angel should output a triangle waveform. It use 1 op amp only so theoretically it should be a square wave form smoother by a capacitor.