# Mods for TC Electronic Vibraclone



## Big Monk (Aug 9, 2021)

The past few days I’ve gone down a rotary rabbit hole. Long story short: Some of the best out there are physically big and power hungry. I have my 2 300 mA taps (I have 2 10 tap Otraki power bricks) occupied by the Strymon El Cap and Flint. 

I did not want to have to run another separate AC adapter (I already have one dedicated to my EHX Good Vibes) so I decided to take a chance on the TC Vibraclone. It’s a pedalboard friendly size and only requires a 100 mA tap, of which I have more than a few left. 

It is not talked about as much as some of the more expensive Rotary sims but it was a good price and I see the potential for 2 mods:

1.) Add a jack for use with an external switch for going between fast/slow settings. Dedicated switch on the pedal would still work with no external switch in use. 

2.) Add a jack for expression pedal control of the speed. 

The simpler expression mod would be easy. What I’d like to do is set it up to have an LED that tracks the Speed rate. 

Can someone point me in the right direction? I have R.G.’s article about adding expression control but need additional info on the LED that tracks speed.


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## Big Monk (Aug 10, 2021)

With respect to #2 above, I'd like an arrangement similar to what my Electro Harmonix Good Vibes has:

1.) Whether the expression pedal is hooked up to the good vibes or not, it has an LED that tracks the speed setting;

2.) When the expression pedal is hooked up, the speed setting on the unit sets the range of the expression pedal.

I guess I'm curious is anyone has ever done something like this.


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## Feral Feline (Aug 10, 2021)

Don't know if this will translate to your Vibraclone, but here's some Rate LED hacks:

https://forum.pedalpcb.com/threads/yellow-led-duo-phase.5709/ 
(DAN FRANK’s POST)


Also mentioned here





						Phaser Phriday- daughters of the dragon
					

Phaser Phriday- daughters of the dragon



					www.madbeanpedals.com


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## Big Monk (Aug 10, 2021)

Feral Feline said:


> Don't know if this will translate to your Vibraclone, but here's some Rate LED hacks:
> 
> https://forum.pedalpcb.com/threads/yellow-led-duo-phase.5709/
> (DAN FRANK’s POST)
> ...



Unfortunately I can’t get the schematic. TC are real sticklers. They won’t even give them out for people doing their own non-warranty repairs. 

I’ll dig I to this stuff and see what I can come up with.


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## shalinc (Aug 21, 2021)




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## shalinc (Aug 21, 2021)

this is my first pedal i’ve ever modded so excuse the poor craftsmanship. this mod controls the speed of the vibraclone. for some reason it doesn’t work when the speed knob is either at the lowest setting or the highest setting but if you leave the knob anywhere else, the exp pedal has full control and range. the ramping effect is still in tact, as well.

 another weird thing to note is that if you unplug the exp pedal, the unit cuts off and then back on. but if you turn off the pedal before removing the trs cable than it’s no problem at all. 

i don’t know the ohm rating of the pots or anything but i’m using a standard ehx expression pedal if that helps at all


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## Big Monk (Aug 21, 2021)

I ended up sending mine back and purchasing a NuX Roctary, which I absolutely love.


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## Robert (Aug 21, 2021)

shalinc said:


> this mod controls the speed of the vibraclone. for some reason it doesn’t work when the speed knob is either at the lowest setting or the highest setting but if you leave the knob anywhere else, the exp pedal has full control and range.
> 
> another weird thing to note is that if you unplug the exp pedal, the unit cuts off and then back on. but if you turn off the pedal before removing the trs cable than it’s no problem at all.



My guess (and judging by the big AD DSP it's probably not far off) is that you've tapped onto a pot that is configured as a voltage divider feeding an ADC.  

When the pot is at minimum the wiper is grounded, when the pot is at maximum the wiper is directly connected to one of the power rails.     This would explain why your expression pot has no effect in either of these conditions.   If that is the case you'll want to avoid turning the expression pot to either extreme while the internal pot is at (or near) maximum.   This is effectively shorting a power rail to ground.

This would also explain why plugging/unplugging the expression pedal causes the pedal to reboot.    You might want to consider adding a 1K current limiter between the PCB and the expression jack to prevent damage.


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## manfesto (Aug 21, 2021)

Robert said:


> My guess (and judging by the big AD DSP it's probably not far off) is that you've tapped onto a pot that is configured as a voltage divider feeding an ADC.


Unrelated but what kind of deal did TC get on those SHARC processors that they’re putting them in their line of ~$60 pedals


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