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Viewing 17 posts - 1 through 17 (of 21 total)
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  • #38240
    Ben Ji
    Participant

    is  this what you call oscillate ? this is Lug 6 after i replaced IC3 with a more trustworthy supplier. did not test the pedal yet but i can tell you i never had this on this Lug

    #38239
    Ben Ji
    Participant

    <span style=”-webkit-tap-highlight-color: rgba(0, 0, 0, 0);”>g2 is very well grounded i have verified it is connected to the jack and from the jack i go to another ground.</span>

    with no IC3 we have

    L2: 2,5/2,3v
    L3: 3,7/3,8v
    L6: 2,8v
    L7: 8,9v

    all other Lugs are 0v

    #38225
    Ben Ji
    Participant

    i reflew around C8 , R22/24/25 + IC3 socket. no progress

    #38171
    Ben Ji
    Participant

    OK i’ll try to reflow a few of these around and let you know how it goes. thanks a lot

    #38152
    Ben Ji
    Participant

    i agree.. i need to source proper ones. this pedal will not work with this PNP. thanks!

    #38150
    Ben Ji
    Participant
    • Pin6 clearly does not oscillate
    • I tried reflew C8 solder joints

    What do you think about the JFET values i gave ? does it look good to you?

    #38143
    Ben Ji
    Participant

    the speed pot affects voltage on Pin2 up or down a bit if i turn it clockwise or counterclockwise but does not oscillate ‘alone”. Pin6 voltage does not change when i turn the speed pot

    #38142
    Ben Ji
    Participant

    Regarding Q5 2N4125, i have tested a few from the bag i have (x10) i didn’t touch the one on the board.
    I used the FNIRSI LCR-P1 which provides:
    – DC current gain -> hfe,
    – base-emitter voltage drop -> Ube,
    – Ic/Ie, collector-emit-ter reverse cutoff current -> Ice

    Here are the values for 3 FET i took from this bag (new), i’m not sure these value matches the datasheet. What do you think? It is difficult to say because there are so many values.

    #38139
    Ben Ji
    Participant

    I understand and agree about what you are saying about replacing components. I would not got into detail about the why i did this but now i understand why i should not.

    R23 down side : 2,13V
    R23 top side : 2,83V
    Q5 is 2N4125

    will bring more complete answer later

    #38130
    Ben Ji
    Participant

    Oh I am so sorry about that, yes i know how to read this numbering in theory but clearly i got distracted 🙁 i read column by column, so after translation to correct reading method this makes:

    • IC3/P6 voltage is 8,94v and does not oscillate (tested with classic multimeter)
    • i have pushed harder the IC and had a few clicks showing they main not have been properly clicked
    • R24 is 4,7k
    • i just change R23 for a new one and R14 because i had some doubts
    • ——————-
    • IC3/P1: 6,68v
    • IC3/P2: 2,14v (reading starts at a higher value then stabilize)
    • IC3/P3: 3,89v
    • IC3/P4: 0v
    • IC3/P5: 0v
    • IC3/P6: 2,83v (reading starts at a higher value then stabilize)
    • IC3/P7: 8,95v
    • IC3/P8: 7,92v
    • —————-
    • IC1/P1: 0v
    • IC1/P2: 4,81v
    • IC1/P3: 3,24v
    • IC1/P4: 0v
    • IC1/P5: 0v
    • IC1/P6: 4,8v
    • IC1/P7: 9,10v
    • IC1/P8: 0v
    • —————-
    • Ic2/P1: 4,8v
    • ic2/P2: 4,8v
    • ic2/P3: 4,7v
    • ic2/P4: 9,10v
    • Ic2/P5: 4,7v
    • ic2/P6: 4,8v
    • ic2/P7: 4,8v
    • ic2/p08: 4,8v
    • ic2/p09: 4,8v
    • ic2/p10: 4,7v
    • ic2/p11: 0v
    • ic2/p12: 4,7v
    • ic2/p13: 4,8v
    • ic2/p14: 4,8v
    • —————–
    • Q5 bottom pin ( on the board picture) : 4,8v
    • Q5 middle: 4,23v
    • Q5 top pin: 2,83v
    • R23 top: 2,3v
    #38127
    Ben Ji
    Participant

    #38126
    Ben Ji
    Participant
    • IC3/P6 voltage is 8,94v and does not oscillate (tested with classic multimeter)
    • i have pushed harder the IC and had a few clicks showing they main not have been properly clicked
    • R24 is 4,7k
    • i just change R23 for a new one and R14 because i had some doubts
    • check video for pot/lug2 test
    • IC3/P1: 6,68v
    • IC3/P2: 2,14v (reading starts at a higher value then stabilize)
    • IC3/P3: 3,89v
    • IC3/P4: 0v
    • IC3/P5: 7,92v
    • IC3/P6: 8,95v
    • IC3/P7: 2,83v (reading starts at a higher value then stabilize)
    • IC3/P8: 0v
    • IC1/P1: 0v
    • IC1/P2: 4,81v
    • IC1/P3: 3,24v
    • IC1/P4: 0v
    • IC1/P5: 0v
    • IC1/P6: 9,10v
    • IC1/P7: 4,8v
    • IC1/P8: 0v
    • Ic2/P1: 4,8v
    • ic2/P2: 4,8v
    • ic2/P3: 4,7v
    • ic2/P4: 9,10v
    • Ic2/P5: 4,7v
    • ic2/P6: 4,8v
    • ic2/P7: 4,8v
    • ic2/p8: 4,8v
    • ic2/p9: 4,8v
    • ic2/p10: 4,7v
    • ic2/p11: 0v
    • ic2/p12: 4,7v
    • ic2/p13: 4,8v
    • ic2/p14: 4,8v
    • Q5 bottom pin ( on the board picture) : 4,8v
    • Q5 middle: 4,23v
    • Q5 top pin: 2,83v
    • R23 top: 2,3v
    #38122
    Ben Ji
    Participant

    also don’t you think we are missing something more obvious? something pretty stupid i would have done?

    #38121
    Ben Ji
    Participant

    thanksq again. so i do not have oscilloscope hence cannot tell you what is happening right now on IC3/P6. i can only tell you voltage is 8,8v. Also before posting here i worked on this with a friend way more skilled than me and he already identified that IC3/P6 did not oscillate using oscilloscope. we also tried various voltage with the trimmer without luck (very slowly) i tried again right now to test for each increment (trimmer is actually not that difficult to fine tune)

    Additionnaly i have tried the voltage on speed pot lug 2: Voltage does change goes from.. 2.1v and goes up slowly then can go down. the logic of this variation is difficult to understand for me.

    #38118
    Ben Ji
    Participant

    I set them all at 2,08v i hope it is ok. They show all the same voltage. Same issue, sound is not modified. Does it hurt if a bit higher like 2,3v ?

    #38113
    Ben Ji
    Participant

    Did you use the trimmer to set the jfet gate voltages to just over 2v

    I guess you mean at #2 on IC3?

    #38109
    Ben Ji
    Participant

    i bought 2N5952 matched transistors from banzai music. You can see one of them here.

Viewing 17 posts - 1 through 17 (of 21 total)