Problems with Envelope Filter

[Harris]

Sorry.  Not a homebrew, but thought some of you guys could point me in the right direction.  I've got an Ibanez Envelope Filter (sorry, can't remember the model number, but it looks like it was during the "10 series" era).  It used to sound fantastic, but now it has lost some of its umph.  It still works, but not at the level that it used to.  Some of the envelope filter effect is gone and so has some of the output volume.  It did not gradually decrease, just one day...it didn't work as well.  I've built a good number of tube amps, but my knowledge of pedals is limited.  I did read the debugging page and throught I would at least post here before ordering and replacing all of the electrolytics as a first step.  I just don't know much about the workings of this pedal and thought I would ask people smarter than me first.

THANKS!

[Mark Hammer]

1) Does it show some relative change in response to variations in the sensitivity control?

2) Does it respond diferently to up vs down sweep?

3) Does it show different sound in response to the type of filter mode selected?

4) Have you changed the type of signal you feed it with?  Will it sweep if you plug a fuzz or something hot ahead of it?

Answers to these questions will provide some additional clues of what could have changed.

[Harris]

Great questions.  Basically, the bass end of the sweep fades out and nearly disappears.  This pedal, like I said before, sounds great.  It makes a lot of different sounds, but only one I like....[peak, cranked;] [filter, lp (as opposed to bp)] [drive, up] and [range, low].  From what I can tell, the bass seems to fade out in the sweep across all funtions...but there are a lot of different combinations.  The bass fades are a lot less noticeable when the drive is down instead of up.  Of course, the envelope filter doesn't sound good on this setting either.  Thanks for any help!!!

[Transmogrifox]

It's hard to tell anything conclusive from what you can observe by playing through it...

I would recommend you do the obvious things first, like the following:

Measure the power supply voltage.  If using a battery, replace the battery.

Take it apart and thoroughly clean the jacks with a good quality contact cleaner.
Spray/dust the circuit board
Spray contact cleaner into all the pots and move them around as you clean.
clean the board with a good electronics cleaner removing corrosion, lint, and dust wherever it may be clinging.

Put it back together and see if it sounds as good as it once did.

If it is still sounding badly, then come back and report and see if somebody has some other ideas.