Noise section trimmer voltage?

Discuss Yocto construction and related issues
  • hi guys,
    I am still having trouble with the correct value of the trimmer. I have checked everything and to my knowledge all is good.
    First I had a 47K resisitor at R127 (because of the picture) with getting the maximal value of 118/120mV.
    Now I have changed R127 for a 4K7 resistor wich gives a minimal value of 170/168mV.
    What to do now?
    I would like to have TM4 somewhere in the middle setting, so I can tweak it up or down.
    Should I get a trimmer like "lfo2vco" did? And what value should this trimmer have for my prefered TM4 setting?
  • Shiva Niet wrote:First I had a 47K resisitor at R127 (because of the picture) with getting the maximal value of 118/120mV.
    Now I have changed R127 for a 4K7 resistor wich gives a minimal value of 170/168mV.
    What to do now?
    Try with 22K

    Best regards,
    e-licktronic
    Best regards,
    e-licktronic
  • Shiva Niet wrote:Should I get a trimmer like "lfo2vco" did? And what value should this trimmer have for my prefered TM4 setting?
    Hi Shiva Niet,

    I planned to use a 100k trimmer, but the guys at Maplin gave me a 1M by mistake. However this served the purpose of finding the right value without keep soldering and de-soldering loads resistors. Now my Yocto is up and running I will replace the trimmer with a 100K resistor (this is the closest value to where my trimmer currently set). :)

    Hope this helps.
  • @4teenth, being organized takes time but it has its own rewards. Also, when you do have a multi-meter, it takes less time to measure resistance than by calculating it using the rings. One can always get confused by the colours. Please ensure that you have a complete kit for stuffing a PCB before starting stuffing. Having components in different bags makes it easier for you to access them. Using a sticky tape with components is never recommended as the sticky material is an insulator.
  • Does this voltage change trough the build?

    I had it on 130mV with 100K resistor on R127 when I finished the noise part but now when I finished the Rimshot this voltage is 140mV and can get it to 130mV.

    Also when I trigger instruments with Arduino snaredrum sound like pop and rimshot doesn't work. Can this be related?

    Thanks!
  • Ok got the professional multimeter and now I changed R127 to 4.7K to get 130mV. But still snaredrum and rimshot does not work. I will post my problems in another topic.
  • yeah it looks like roland changed the noise schematic at some point:

    Image

    I might try to do the bottom one instead of what's indicated in the tutorial and see what I can get. Should be an easy substitution.
  • The highest I could get voltage was 50mV so I've reduced R127 to 2K7 and was then able to get 130mV. Will reducing R127 affect any thing else?

    Kris
  • I can't get it to 130mV too, 160mV is the lowest i can get by turning the trimmer.

    When i take a look at the yocto schematics it clearly says that R127 is 47kOhm instead of 4.7kOhm
    stated in the build manual... :?: