Stage Fright

[Kivjah]

  Hi guys

I just finish to build a Stage Fright Phaser and it work strange (that always for me This kind of thing lol) the phaser work good 2 or 3 seconds and after, clean signal... 
That the same in all positions : 5 or 6 stages and the trim change only the deep of the phaser normaly. The lfo work good (led ok).The phase stages are in normal mod (1nf) and i soldering 3,3nf cap (not trying without...) The pcb is clean and my solders're good.

I have some ideas : maybe power problem (i use 9v dc 250ma) normaly that enough.
When i turn off and on the power, it work again 2 seconds, just like a dicharging condenser... Mabye LM13700N problems but why ? i take care with electrostatic...

If you have some idea... 
Thanks guy !! 

Ps : i'm french sorry for my bad english