fx25 question

[Calamardo]

Recently i built the fx25 autowah (thank to Topopiccione for that great project!). Now the question: when i play with the sensitivity at max the filter dont sweep, all i have is a mudy sound, is that normal?. The useful range of the sens control is only 3/4. Thanks!

[Zero the hero]

I don't remember well if my unit behaves the same. Unfortunately, my FX-25 is no longer driven by the envelope follower. I installed the Invisible Touch instead.
What ICs did you use? Maybe, the filter doesn't sweep because at maximum sensitivity the envelope follower cannot feed more current the the filter section. Using rail-to-rail ICs could improve this issue, but I'm not sure if the problem is due to this.
Sensitivity varies in conjunction with the equipment / guitar / guitar volume and tone settings you are using, so this could be another hint while looking for a solution.

[hank reynolds 3rd]

Mine does this...I'm used to seeing the sensitivity control before the IC, but I'm guessing/hoping that chnging C5 might help things ,maybe 0u047 ...


*Quick Hijack*
..Hi Alex...just waiting on a Banzai delivery,then the EH Oct update for the FET will be on its way !!!
damn,your site goes from strength to strength ,Polyphase....mmmmmm 

Sam

[Zero the hero]

*Quick Hijack*
..Hi Alex...just waiting on a Banzai delivery,then the EH Oct update for the FET will be on its way !!!
damn,your site goes from strength to strength ,Polyphase....mmmmmm 

Sam

Have a look: http://www.fennecelectronics.it/smf/index.php?topic=448.0 
A folded Octave Multiplexer! This circuit has been built by a italian stompbox forum user, I asked him which fet he used and I'm waiting for an answer.

[Calamardo]

Thanks for the replys!!!. I used TL072 and NE5532 and i like TL072 over the NE cause is seem to be  more clean to my ears. But i will try the original one (LM1458). 

[Mark Hammer]

Mine misbehaves a little also, sometimes reqiring me to turn the sensitivity way down to "reset" it.  Although to be fair, I monkeyed around with it, and set it up for a little more resonance, as well as installing variable recovery/decay.