voltage @ noise module

Discuss Yocto construction and related issues
  • I checked all the polarities and values for the other components (caps&resistors) I had put on the main board as per instruction assembly sheet and it all looks good.
  • just make the changes as in the service manual at point 5 page 15.

    this will make the adjustment range larger

    i did the same .no problem to get the 130mv.
  • italofrans wrote:just make the changes as in the service manual at point 5 page 15.

    this will make the adjustment range larger

    i did the same .no problem to get the 130mv.
    Thank you for the advice Italo. A few questions to your answer:
    is it normal to see the values I see?
    Is it not an indication that somewhere I did something wrong that may come back out later to haunt me if I proceed this manner?
    Were your parameters this off as well?

    Thanks a lot.
    Appreciate your input on this.
    Best
    Marco
  • Hi Italo,
    I finally found the section in the forum that specifically addresses the problem of the voltage on pin1 so I'll read it more carefully and follow the instructions on it. It can be found atviewtopic.php?f=16&t=155 or viewtopic.php?f=16&t=155

    It seems that the problem occurs somewhat often. Wish e-lictronics had made a note of this on his assembly guide. It would have been helpful and spared me (and others at this point...) some grief.
    By the way, the way I found the section on the forum was by using Google. This forum's search must have some kind of problem because if you query 'yocto voltage noise section' all you get back is
    The following words in your search query were ignored because they are too common words: voltage section noise yocto.
    You must specify at least one word to search for. Each word must consist of at least 3 characters and must not contain more than 14 characters excluding wildcards.
    I don't want to sound ungrateful. I recognize all the good work that e-licktronics has done to make all of this available to people but a working search engine on the forum and more detailed presentation of the assembly instructions would improve the experience of assembly a huge amount!
    Marco
  • I am posting all the info I've collected so far on this issue for other folks who may meet the same problem I have met.
    Here in summary is the situation:

    Many people (see posts in viewtopic.php?f=16&t=155 ) have found issues with using the trimmer to reach the 130mVAC on pin1 of U24 in the Noise section.

    If you have the same problem, don't panic. You seem to be in good company.
    The solution seems to be to change a few of the listed components.

    You can find details of the mod in question in these places:
    - the forum post and responses dealing with the issue itself ( viewtopic.php?f=16&t=155 )
    - in Masutopedals' Yocto building manual ( https://masutopedals.wordpress.com/2016 ... ding-tips/ ) you can find the instructions and a few very useful photos.
    - at page 15, point 5 of the TR808 service manual, downloadable at http://www.ericarcher.net/wp-content/up ... vc-man.pdf you can find some original mod suggestions from the original manufacturer.

    Putting together all these pieces you should have all the info you can desire (and need).

    I will be doing this in the next upcoming days.
    I'll post my result.

    Cheers.
    Marco
  • Hello you all,
    As promised I am updating the post to followup on my tests.

    Even by doing what Masuto suggested in his guide I only came as close as a 240mVAC reading on my multimeter. So I went ahead and wrote Vincent about it. Here is my mail to him:
    Hi Vincent,

    thanks for reaching out to me on this.

    Actually I made the modifications that were suggested on Masuto’s page but I still don’t get the 130mVAC reading. I now get about double that at the lowest setting of the trimmer.
    I don’t know if it is a problem of my multimeter (even though it is a rather new Fluke benchtop meter) which shows an approx 130mVAC reading with the leads not even connected (!) but my limited skills do not allow me to investigate further, in the sense that even if it were the multimeter’s fault, as some have said in the forum to check, I don’t know what to test next. I used another multimeter and the reading in AC was rather similar to the one I got with the Fluke.

    In any case I decided to move on to the other modules and start constructing them.
    Do you think this is a good plan or should I definitely resolve the issue before proceeding further?
    Do you have any ideas on the mV issue for me?

    Thanks for your attention Vincent.

    Marco
    and here is his reply:
    Marco,

    Don't worry about the 130mV noise you can still adjust it by ear.
    You are right to continue the building process.
    Have fun ;)

    Best regards,
    Vincent
    So I would say that this covers the issue for now. I am moving forward at this point on the next parts of the board.
    I'll post my results later on for you all to hear how the noise section calibration influenced (or not) the actual working of the whole system once built.

    Ciao
    Marco