Ditto Looper repair (how to fix a broken switch)

The Ditto looper from TC Electronics is a good looper - in theory-. Easy to use, no audio quality loss due to the high sample rate of the recorded signal, true bypass... Everything to make it the best looper for guitarists!

However, practically speaking, it has downsides: no stop button, which makes loops hard to synchronize, and it is really fragile! Mine did stop working after 6 months of intensive use (I bought it used so I guess it makes more than 6 months total). LED is still working, but I have to press many many many times on the switch before anything happens. Impossible to record loops! It was thus really useless as is.

First, I contacted TC Electronics customer service, and I have to say that they were not helpful. I bought my Ditto used, so I did not have any invoice. However, when the problem happened, it was less than 1 year and a half that the Ditto was issued, and it was guaranteed for 2 years!TC electronics did not agreed and suggested me an exchange, which more expensive than buying a new Ditto in a shop... Thanks TC!

It was try or die then: I tried to repair it!
Here is the step by step guide if you ever need to repair yours.
The main problem seemed to be the switch, which just needed replacement. I dismounted the pedal. First, you need to remove the knob by pulling it with pliers, and unscrew the potentiometer. Then unscrew the backplate. You have to separate the 2 circuit boards that are in the pedal. Indeed, to gain space, the Ditto is composed of two PCB, linked by connectors, allowing to fit such a complex system in a small enclosure (1590A size!). You have to pull up gently the top part of the circuit, holding the jack connectors. Then, you have two screws to remove to be able to pull the top part of the PCB. You should have something like this :

The "naked" Ditto. We can see the connectors linking the 2 PCB

On the top of the circuit, we can see the LED and the chips which allow recording of the audio signal. Everything is SMD, except some big blue 100uF electrolytic capacitors. If we look at the bottom PCB, we can see that the switch is not a classic switching system, but a spring which activates a microswitch on the PCB.

The culprit: a microswitch (round button on a square),
next to a 100uF electrolytic capacitor

This is the same system than in the Line6 DL4, famous for switch failure! The faulting component is therefore very likely to be this microswitch. Microswitches are fragile compared to a classic footswitch, and cannot resist as many activations. There are 2 solutions:

• Either replace the microswitch by the same component (which can result in other failures later)
• replace the spring + microswitch system by a real 1PST footswitch, more resistant and easier to replace later.

The second solution was the best for me.

First, we have to dessolder the faulting microswitch. However, the capacitor can prevent us from reaching all the bottom lugs of the switch, so we have to remove it first. I have to say that soldering is fun and easy, however dessoldering is really a pain in the a...! Commercial components are soldered with very little solder, which is dry and on both sides of the PCB... You have to eat it quite a bit before it melts, yet do not heat too much because SMD components are very sensitive to heat! So take your time while doing this job, and wait times to times for everything to cool. You can see that there are 2 very fragile SMD IC just near the switch, so be careful, and dessolder only by the bottom of the PCB. A dessoldering pomp is the best for this kind of job. I managed to dessolder the two bottom legs of the microswitch that way. Top legs were impossible to reach from the top because of the jacks, and I did not want to overheat the circuit. So I just broke it by twisting the switch up and down. The 2 legs got stuck in the holes, so impossible to replace the microswitch. This is clearly the most difficult part of the repairing job. Once you did it, the rest is easy.

 

The PCB once you removed the capacitor and the microswitch.

The two lugs near the jack are still visible

We can see 4 pins for the microswitch. In fact, they are connected 2 by 2 vertically. We can the traces connecting the two holes vertically. There are also 4 pads to mount as SMD microswitch. 1PST footswitch has two lugs, so you have to cennect each lug to one hole on the left, and one hole on the right. Do not forget to use a classic "normally opened" footswitch.

The problem is that a classic 1PST soft footswitch is too big to fit in the enclosure. In facts, it is too high to fit between the 2PCB, and too long at the base. There are 2 solutions:

• either doing a rehousing of the pedal in another enclosure. This is difficult because you have to adapt the jacks input/output and power supply, which means more dessoldering, which means more risks of breaking the pedal.
• Using a different type of switch that would fit the enclosure

After a bit of research and help of people from madbean pedals forum, I found that a "arcade" type of switch would perfectly fit in the enclosure!
We can then remove the old switch (unscrew it from the top), and remove the flange in the switch hole. We can then place the switch in:

Each pad of the former switch can then be connected to the switch:

 

Lets put it back together and boom! We are done! Everything works again like a charm, and with this system, I am almost sure that the pedal will stay functional a bit more. Moreover, this type of arcade switch is easier to replace if it broke.

It is also easier to use, as there is no more latency between the moment when you press the switch and the activation of the effect. It is thus easier to have loops with the right tempo, or not to fail by pressing the switch too softly.

And moreover, it has a really cool look!

The new arcade switch on my functional-again Ditto looper!

Every single pedal of TC Electronics have this switching system, so they are expected to break a lot... You can use this guide to repair them.