# Regular Trouble with PLL Pedals



## nate433 (Apr 7, 2022)

Hey everyone. I've yet to have a PLL pedal work properly. They never seem to quite have the same amount of sustain as the demos I see online. At this point I've probably built 150+ pedals and the only ones that don't work properly are DBA ones that have hard to source parts (looking at you Robot Fuzz...) and the 3-4 PLL pedals I've made. 

I've taken a bunch of voltage measurements of the 2 I currently have, a Bit Commander and Data Corrupter. A lot if not most of the '0' measurements was sometimes like .01 mV. So figure that's pretty negligible. I wasn't sure if there were certain knob positions you should have to get the best readings. So I just left everything at noon. 

All of the chips were sourced at Tayda, and I've swapped most if not all of them in the past with others I had lying around and it didn't make a difference. 

On a somewhat related note, how do you know if the voltages are what you should expect? I don't see anything on the datasheet. Is it just experience and knowing how the chips need to function for the pedal to work? Or are you like analyzing it in LTSpice or probing a known working pedal. I would love to be able to understand what the readings mean without needing to ask you all for help. It is greatly appreciated though.

Thank you in advance!

Bit Commander


PINIC2 - CD4024BE1Stars at ~2.5V and drops2031.2mV41.9mV5.9mV6070809010011012013.6mV149.62V

Data Corrupter


PINIC2 - CD4069UBEIC3 - CD40106BEIC4 - CD4024BEIC6 - CD4046BEIC7 - CD4017BEIC8 - CD4017BE14.513V4.481V9.32v9.36V4mV024.528V4.503V004mV034.470V9.26V002.6mV9.35V44.50V1.1mV9.35V9.36V2mV054.494V09.35V09.35V064.506V9.31V00.7mV070V003.651V008Starts at .39.3V000090001.02V9.35V0105.3mV0046.5mV0011009.35V000125.5mV09.35V8.02V09.35V1300000149.35V9.33V9.36V9.35V9.31V9.35V15000169.35V9.35V9.35V


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## nate433 (Apr 12, 2022)

Bump?


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## nate433 (Apr 21, 2022)

I am now officially beckoning the patron saint of troubleshooting 
@Chuck D. Bones
 🙏


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## jesuscrisp (Apr 22, 2022)

How about you post pictures of your build?


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## HamishR (Apr 22, 2022)

What's PLL? Pretty Lady Luck? Poor Lad's Loss? Poo La La? Praised Lord Lactates?


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## mdc (Apr 22, 2022)

The build doc for the madbean version of the data corrupter has a handy chart with expected voltages on each pin:


			https://www.madbeanpedals.com/projects/_folders/FilterMod/pdf/ToneVirus.pdf
		


I think pin 14 on the 4046 is the signal input, so I don't think you should be seeing 9V there...? I could be wrong though.


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## mybud (Apr 22, 2022)

HamishR said:


> What's PLL? Pretty Lady Luck? Poor Lad's Loss? Poo La La? Praised Lord Lactates?


Phase Locked Loop?


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## Betty Wont (Apr 22, 2022)

Its the nature of PLL. I personally can't stand them due to the low sustain, and all the static from start/stop/false triggers. As far as how they sound better in demos, the same tricks apply as for octave effects, neck pickup, tone rolled off, and a boost in front. Guitar isn't ideal for PLL due to the nature of the string variables, its more of a synth effect.


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## Feral Feline (Apr 22, 2022)

PLL = Pedal Lacking Logic


PLLs, I love 'em!


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