Gravity Wave (Verified)

[bigzed]

I am definitely getting slap back on the Dimension control with this mod as per the demo.

[bigzed]

I also put a 4.7uf for C20 (+ side to pin 12 on the lm324) Slows it down to a more manageable level.

[wainer said]

What would that VC entry ? this layout? tanks

[mauzau]

I changed the values suggested by Bigzed and it sound like the demo watched on you tube.
Thank you Bigzed!

[impycat1]

Changed the recommended components this evening. Replaced C20 with a 4.7uf non polar as I had a few in stock. Works perfectly now. 

Thanks Bigzed.

[stringsthings]

Just finished my build.   This pedal is very versatile.  I'm still surprised by the innovative uses of the PT2399 chip.
Thanks for the project Bean!  And thanks to all those who found the optimum parts substitutions.

I also used a 33nf for C9, 10k for R9, and a 4.7uF for C20.  For C20, the + side connects to pin 13 of IC3/LM324.

[Alex]

Chris has checked his original pedal and posted the corrections on https://tagboardeffects.blogspot.fr/2016/02/madbean-gravity-wave-earthquaker.html
The only difference between Brian's schematic and the original is C9 (not 330n but 3n3).
R9 should be 1K.

[/)an/)an]

Hi!

Im fairly new and was wondering if any etchers would be able to etch me a pcb of the gravity wave? How much eould you charge etc? And to ship to new zealand?

Thanks very much!

D

[lars-musik]

Hello madbeaners,

I am planning to build a Gravity Wave for Bass use. Would you recommend a dedicated blend feature or could you estimate the bass loss if the circuit is kept as it is and the "Depth" knob does all the blending work?

Thanks for your help, Lars

[plush]

Hi guys,

Any ideas how to get rid of lfo ticking noise? It persists even when the pedal is turned off.

Thanks.

[Scruffie]

Hello madbeaners,

I am planning to build a Gravity Wave for Bass use. Would you recommend a dedicated blend feature or could you estimate the bass loss if the circuit is kept as it is and the "Depth" knob does all the blending work?

Thanks for your help, Lars

I should think it'd be fine as designed for bass, the signal caps are quite large already and dry signal is always mixed in.

Perhaps increase C1 to 220nF.

Hi guys,

Any ideas how to get rid of lfo ticking noise? It persists even when the pedal is turned off.

Thanks.

How neat is your wiring? If it's happening in bypass that suggests to me your rate pot or other LFO wires might be passing by something carrying signal.

But, you can try adding a large electro (22-100u) across the 324 power pins as close to the actual chip as physically possible, positive to pin 4, negative to pin 11.

[plush]

How neat is your wiring? If it's happening in bypass that suggests to me your rate pot or other LFO wires might be passing by something carrying signal.

But, you can try adding a large electro (22-100u) across the 324 power pins as close to the actual chip as physically possible, positive to pin 4, negative to pin 11.

I don't think there is something with my wiring.
There is also no unwiped rosin or solder bridges or ground loops and etc.

I simply plug the pedal into my amp and switch it to high gain channel and lfo ticking appears. When i switch it to clean channel, lfo ticking disappears.

This made me think that there is smth with my amp (mark V:25). To check it, I plugged the pedal into my slo100 and experienced the same thing.

I've also tried to put some kind of overdrive or dist after gravity wave and then plug it into my clean amp. As expected, lfo ticking appeared as soon as the drive pedal was engaged. Fun thing, there is no ticking when drive pedal is placed before the chorus.

I tried to power the pedal with both 9v battery and isolated power supplies (trex chameleon, cioks coikolate) with the same results.

Unfortunately, capacitor trick also did not work.

Sorry for my english.

Crappy gutshot attached:

[Boba7]

Did you try moving the depth and rate pot away from right under the jacks? Could make a difference I think.

[plush]

Could make a difference I think.

Why should it? The pots are screened. They can't be a source of interference.

[Boba7]

A phaser I built some time ago had this problem. I think it was the rate pot that was too close to the input or output jack, causing ticking. Can't remember exactly.

I could be totally wrong of course! But it wouldnt be difficult to just take out the rate pot of under the jack and see if the ticking goes away.

And the dust caps protect from contact, but won't do anything again lfo ticking or other interferences.

Hope you get rid of the ticking!!