# Pendulum Harmonic Tremolo



## airvian (Apr 28, 2022)

The Pendulum really needs a mix control. I kinda implemented one by plugging it in an external fx loop, but that's not ideal. Does anyone have a working solution already?


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## jesuscrisp (Apr 29, 2022)

While a mix control would be nice too, I found it to be much more usable if you change the output cap to a much smaller value (68nF instead of 1uF) and put a small capacitor over the volume pot to tame some highs (2.2-4.7nF).


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## airvian (Apr 29, 2022)

jesuscrisp said:


> While a mix control would be nice too, I found it to be much more usable if you change the output cap to a much smaller value (68nF instead of 1uF) and put a small capacitor over the volume pot to tame some highs (2.2-4.7nF).


yeah I did those mods and they sound way better than without them. Being able to blend in dry signal would take the effect to new levels though.


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## airvian (Apr 29, 2022)

I now ordered another Pendulum PCB and a switch mounted buff n' mix from GuitarPCB. I will also do the output and volume pot cap mods, then update the thread once I have all the parts and the pedal built.


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## Sparky_mark (Apr 29, 2022)

Just finished building this today, haven't had a chance to play around with it properly so not sure if I'll change things yet. Though I did socket the LED's to see if they made a difference in colour/strength. 
I have noticed that its very loud! not sure if thats the LED's I used? Any one else's loud as hell?


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## Dan0h (Apr 29, 2022)

Sparky_mark said:


> Just finished building this today, haven't had a chance to play around with it properly so not sure if I'll change things yet. Though I did socket the LED's to see if they made a difference in colour/strength.
> I have noticed that its very loud! not sure if thats the LED's I used? Any one else's loud as hell?


Mine also is very loud. It’s all those Ic amps.


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## Sparky_mark (Apr 29, 2022)

Dan0h said:


> Mine also is very loud. It’s all those Ic amps.


Ha yeah that would do it! Waiting to put my daughter to bed so I can play around with the LED's and see what happens. I have a 10mm LED which I'm tempted to put it, just for the hell of it!


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## jesuscrisp (Apr 30, 2022)

The volume pot would be much better as a log taper and since it's a gain control for a boost stage it could also be a smaller value.


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## airvian (May 1, 2022)

Has anyone tried using a vactrol chip instead of the LED/LDR combo? I am inclined to not do the LED/LDR combo on the planned Pendulum with Mix control for consistencies sake as I found the whole LED/LDR thing a hassle in my original build.


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## Sparky_mark (May 4, 2022)

jesuscrisp said:


> The volume pot would be much better as a log taper and since it's a gain control for a boost stage it could also be a smaller value.


I might try that at some point, it’s an easy swap. Would you use the same value?


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## airvian (May 5, 2022)

So I finished the build. It sounds great. The Buff 'N Mix really makes all the difference. I also socketed R5/6/7/8 so I can mess around with the filters if I feel like it. The depth control still has not quite enough range in it if you want to go for a really intense, choppy effect, but it makes for a nice and subtle harmonic tremolo effect when everything is at noon. I did the vactrols myself with a diffuse orange LED and a GL5516 LDR. I also installed a 4.7nF cap across legs 1 and 3 of the volume control (which I also changed to an A100K). I also switched the output cap for a 47nF cap to cut some bass. It sounds really transparent now. Just make sure to only use lugged pots. Using PCB mounted pots like I used for the rate and depth control, pushes the main PCB too far towards the buffer PCB and makes it all a bit of a hassle to get it all to fit without getting any shorts.


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## jesuscrisp (May 5, 2022)

There definitely is a joke about a Harmonious Monk from wish.com in that picture. 😂

Good job! Maybe one day there will be an improved Pendulum incorporating fixes like that?


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## airvian (May 5, 2022)

jesuscrisp said:


> There definitely is a joke about a Harmonious Monk from wish.com in that picture. 😂
> 
> Good job! Maybe one day there will be an improved Pendulum incorporating fixes like that?


Yes  Incorporating a rip/joke on a super hyped pedal in my builds has become a bit of a theme around my projects lately. All the joking aside though: The way the pedal is set up now, I can basically get Monk tones out of it easily (minus the choppieness and amplitutde trem of course) so the comparison isn't just an optical one now to be fair.

Thanks btw. There definitely should be an improved version incorporating the fixes - including trimpots to adjust the filter and depth on the fly (I might add those later on, but I don't have any trimpots left in my stache (the last one I had was the one I put on the mix board to adjust the signal level going into the pedal (it is set at 0 Ohms atm so 100% is going in). The A100K volume pot could also use a lower value in retrospect. 
@PedalPCB


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## Sparky_mark (May 28, 2022)

airvian said:


> So I finished the build. It sounds great. The Buff 'N Mix really makes all the difference. I also socketed R5/6/7/8 so I can mess around with the filters if I feel like it. The depth control still has not quite enough range in it if you want to go for a really intense, choppy effect, but it makes for a nice and subtle harmonic tremolo effect when everything is at noon. I did the vactrols myself with a diffuse orange LED and a GL5516 LDR. I also installed a 4.7nF cap across legs 1 and 3 of the volume control (which I also changed to an A100K). I also switched the output cap for a 47nF cap to cut some bass. It sounds really transparent now. Just make sure to only use lugged pots. Using PCB mounted pots like I used for the rate and depth control, pushes the main PCB too far towards the buffer PCB and makes it all a bit of a hassle to get it all to fit without getting any shorts.
> View attachment 25950View attachment 25953


Thanks for the run down on what you did, sounds like it wouldn’t be too hard to do the same. I may steal you ideas at some point for my own pedal!


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