Thursday 6 October 2016

Revisiting the Ibanez Echo Shifter

After repairing the second Echo Shifter, the PCB sat on the bench for a few days before I re-assembled it. When I did, I found that it had stopped working again. It would light up, but there was no signal in either effected or bypass modes. When I played with the controls I found I could still get it to oscillate by changing delay times with the oscillation switch on, so I knew the delay and output circuits were good.

I opened it up, connected a signal to the input jack and started tracing to see where it died. It wasn't getting past the input jack. Measuring continuity, I found that the jack tip and sleeve were shorted together. I desoldered the jack and it tested fine out of circuit. There is another choke/filter at the input jack, presumably to keep any high-frequency digital noise out of guitar cables, and it looks just like the failed one on the power input. I took it off, and the jack was no longer shorted, but no signal was getting through. Shorting across the pads as before and everything works again. I measured the part out of circuit and the pins were shorted together in a way that doesn't make sense to me at all. It seems like they fail both as open circuits and as shorts.

L6 removed and pads shorted

This is probably totally fine as a fix, and I couldn't see any clock noise or similar on the input jack. I decided to replace the jumpers with some ferrite beads to help cut any high frequency crap. 0805 parts will just about fit, the ones I had are 1 kOhm at 100 MHz.

L6 populated with ferrites

There is another one of these filters at the output jack, I replaced this part at the same time.

L7 replaced wit ferrites as well

Technically these parts have a 500 mA rating but I decided not to add them to the power supply input, as I worried about reliability.

After re-assembling and punishing the switches and jacks for a little while all seems good. This should make the ES-2 closer to bulletproof. Hopefully some more dead units can be revived as well.
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29 comments:

  1. Anonymous15 November 2016 at 06:13

    Where do you found SMD 0805 Ferrit 1kohm 100 MHz with rated current 500ma? I can only get those with rated current 200ma:

    BLM21AG102SN1D Murata

    Is the value to low? Which part can you recommend?

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    1. krivx15 November 2016 at 08:13

      I think that part will work. If you are replacing the input and output filters then the current ratings aren't really critical.

      If you are replacing the power filter then that part may not be rated high enough. I didn't use a ferrite for that though, I just used wire and I have had no noise issues.

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    2. Anonymous15 November 2016 at 08:49

      ok superb. Very nice examination of that device. This power problem can be read quite often in the internet ;)

      I can see that in several documentations the BLM21AG102SN1D is described with 500mA rating and in more depth documeantation of muRata with 200mA rating... (so i believe it's designed for 200mA only)

      >I didn't use a ferrite for that though, I just used wire and I have had no noise issues.

      independently that your work is DIY - could the wiring be harmful to any electronic circuit/or connected external devices? I have too little knowledge for what the original components were. As far as I understand that these components serves for the filtering of noise only, or?

      thx..

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    3. krivx15 November 2016 at 09:41

      >independently that your work is DIY - could the wiring be harmful to any electronic circuit/or connected external devices? I have too little knowledge for what the original components were. As far as I understand that these components serves for the filtering of noise only, or?

      Yes, these components are there to filter noise. It's very common on high speed digital systems to see ferrites on inputs or outputs to keep switching noise out of any external equipment. Especially so where cables are connected, as they can radiate rf noise. I am pretty certain that these parts were included so that the pedal is compliant with EMI/EMC laws around the world. I would be surprised if removing them would actually be harmful, but I ended up using ferrites as replacements just for insurance.

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    4. Anonymous15 November 2016 at 10:24

      Ok, thx for your fast reply.

      The question refers more to the simple bridging the power filter. so should not be a problem for long-term use?

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    5. krivx15 November 2016 at 11:46

      No, I can't see any reason why it would cause problems. The pedal in the article above has been powered and used for dozens of hours without any changes.

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    6. Anonymous16 November 2016 at 07:46

      thanks, for all your effort.

      Delete
  2. Anonymous15 November 2016 at 08:47

    This comment has been removed by the author.

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  3. Anonymous19 November 2016 at 15:37

    Btw: is there a way to find out the high of the output impedance of es2? I don't find any info.

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    1. Anonymous19 November 2016 at 15:58

      so my question is more related to:

      It's ok to connect the output to a 'normal' mixer input (std. output impedance max 1k?) or is therefor a DI (Hi-Z) input or preamp needed? Sadly I can not found any output impedance specs about that.

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    2. krivx20 November 2016 at 14:07

      I think it should be fine either way, though 1kohm sounds more like a microphone input to me. I don't know the output impedance of the es2, one of the pedals I had came with a manual but I have sold it.

      You could measure the output impedance, it's not very difficult https://www.youtube.com/watch?v=ieAhBejHe2M

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    3. Anonymous20 November 2016 at 22:28

      Ok, I have found the spec on inet: 10k Ohm output. That's more as aspected. If I want to go direct into a mixer's line in without using a DI box, could it damage the mixers line input or the es2 themselves, or will it only mess up the sound (because of impedance mismatch)?

      Greetings

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    4. krivx21 November 2016 at 11:35

      You won't damage anything. Worst case is that the signal will be attenuated or will have lost some high-frequencies. Either could probably be fixed with adjustment on the mixer. Try it out and see how well it works.

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  4. Anonymous20 November 2016 at 22:27

    This comment has been removed by the author.

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  5. Nate7 January 2017 at 15:37

    Hi there! I have an ES2 that will not power up. One day I plugged it into a power supply I had used many times and the lights flashed on and then promptly went out. Since then, it has not powered on at all. I opened up the pedal and took out the PCB. Nothing looks blatantly burned, charred, or broken. The pedal I have is like the model you repaired which had the power issue, not like the one with the broken slider. It seems that Ibanez has had a few iterations of the PCB, probably because of all the issues people have experienced. Would you be interested in troubleshooting this unit for me? I figure I have nothing to lose since it has just been sitting in a closet, broken, for over a year. Any help would be appreciated! Thanks!
    -Nate

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    1. krivx23 January 2017 at 14:41

      Hi Nate, sorry for the late reply.

      I haven't been taking on repairs lately, I haven't had as much free time as I would like. I would try the fix from my first post on the ES2 if you have power issues.

      I don't know if there are multiple revisions, I have only worked on 2 pedals and didn't notice any changes.

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  6. John13 September 2017 at 13:18

    This post and your previous post about the Echo Shifter helped me fix mine. I had to short L1 and L6 but now it works good as new!

    Thank you so much for the detailed post! Seriously, it means a lot that you take your time to do this.

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    1. krivx13 September 2017 at 14:18

      Thanks for letting me know. It's great to hear that someone has had a successful repair :)

      Delete
  7. Floris3 October 2017 at 13:38

    This comment has been removed by the author.

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  8. Floris4 October 2017 at 10:03

    I also was able to repair my Echo Shifter by replacing L1 (at power input) and L7 (at output jack).
    Thanks a lot for your posts about this problem and how to fix it!

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    1. krivx6 October 2017 at 08:04

      That's great to hear. It sounds like this is the most common failure mode.

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    2. Unknown17 November 2017 at 01:15

      You helped me fix mine as well, you hero!!!

      Delete
  9. NHTMF10 November 2017 at 06:31

    I tried to fix my friends, I shorted L1 and it powered but with a real crappy noisy signal and no delay. I then tried to short the input jack but now I get no power again? BTW this one also has the trimpot wired as you describe in another post, very odd!

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  10. Retrofuturismo24 March 2018 at 05:04

    Man, thanks a lot I just repair mi ES2. I have some questions.
    Why do I need to filter the high frequencies in this type of pedal? considering that most pedals do not.
    What ma value do you recommend using for power input?
    Thanks :)))

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  11. seroquel24 March 2018 at 14:16

    is it possible to set up an expression pedal connector in order to avoid fumbling w that ****ty slider?

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  12. sclr7 April 2018 at 01:38

    Thanks for the info. Just fixed my echo shifter by doing this to L7. I could see the tiny ribbon of copper burned out.
    Strange thing was I couldn’t seem to get a signal by bridging with a loose wire for testing. But once I removed the burnt piece and soldered down the parts it worked perfectly. Thanks!

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  13. fixtrop18 November 2019 at 07:14

    Iknow that this is an okd thread,but do you have a schematic for the Echo shifter as I have one with no power.Thanks.

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    1. Bannane8928 November 2019 at 08:24

      Hi, I'm also interested with the schematic, pedal power up sound goes out with switch on and off but no effect applied ... Thanks

      Delete
    2. Bannane8929 November 2019 at 08:33

      Also if somebody could give me the value of C77 that would be very helpful, many thanks

      Delete

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