EHX Wiggler LFO thump fixed

[wavley]

So I've owned the Wiggler for a number of years and it's really only useable if you roll off the lows after it because of the LFO thump down in the really lows, which is fine for guitar but I also play Bass VI and would like to use it for those Twin Peaks kind of tones but having to high pass it so much takes the impact away from the bass.  Also, it eats tubes unless you use more sturdy JAN tubes or something.  I tried the internet advice of changing V2 to a 12AU7, which helps but it's still there just with less gain and it really takes the impact of the Trem section away.  I tried current limiting and even cutting out the Rate LED completely and it still didn't work.

I have my doubts that Puretube's original circuit thumped like this given what a genius he is with stuff like this.

So I broke down and looked at the other forum to see if there was a schematic and there is, in a thread that they were incredibly mean to puretube by the way.  First thing that jumped out at me was the amount of high passing on the output that made me think "OK, they're trying to get rid of the thump, why didn't they just find the thump and get rid of it?"  Then I saw it, the power for the LM324 used for the oscillator shares the 12v rail for the tube filaments, so it's actually pulsing the heater current going to the tubes.  A couple of 1000uF caps on the 12v rail later and no more thump, I could actually put a 12AX7 back in and get the strength of the Trem back, then I dropped V2 back down to a 12AT7 because it had a little too much gain for me.  It still makes some motorboat kind of noises when you really crank the intensity and rate, but not the sub moving thump that it had before.

Hope this helps some folks with this small annoyance that comes out of a really great sounding pedal.

[Processaurus]

Wow, thanks for the tip!  I liked the sound of the effect but stopped using mine because of the crazy sub frequency garbage that comes out of it.

So you just bypassed the 12v supply feeding the LM324 with the 1000uF's?

[wavley]

Wow, thanks for the tip!  I liked the sound of the effect but stopped using mine because of the crazy sub frequency garbage that comes out of it.

So you just bypassed the 12v supply feeding the LM324 with the 1000uF's?

Yep, I just paralleled both C23 and C24 with some 1000uF caps, plus a while back I had added a series limiting resistor to the rate LED, I don't remember what value I used there.  1000uF might have been overkill, but I had them laying around from my last Tayda order and I'd rather overkill and have it fixed.