Home GuitarPCB Forum GuitarPCB Build Support Boogie 57 loud.

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  • #29853
    M. E. Moriearty
    Participant

    I finally got around to finishing my Boogie57, and I like the sound, but a couple issues.
    1) The pot takes it from no gain to much gain instantly. This may be related.
    2) Most important, unless it’s related to that same resistor, it’s loud. Like, absurdly loud. Testing it through my amp, I had to set the amp so bypass was barely audible–I could head the actual guitar louder–and turning it on went LOUD. Like from volume 1 to 6 just from the footswitch.
    I mean, it’s just an old Fender Champ 15, but it’s no slouch for the el cheapo.
    3) It creates a loud buzz. So far I attribute it to testing with the pedal unclosed and using my only available short cord, which places it right next to the amp. Will check into this later.

    On the other hand, I didn’t have any trouble with biasing like I’ve seen. One trimmer is pretty much bottomed out, but all the transistors read at 5.00. I think I’m reading it right (drain should be far right, with flat side up?) and I assume I’ll have to re-bias after fixing.
    Next time, I’m stocking up on 9mm pots. Offboard wiring all of these was the least fun thing I’ve done outside of work. And I do autopsies. Props to you guys that make the massive combo pedals.

    #29855
    M. E. Moriearty
    Participant

    Totally skipped the pictures…

    #29866
    Barry
    Keymaster

    Typically when overall volume has increased dramatically it is because of an incorrect resistor value.

    Likewise when this happens noise is also increased.

    I would check each resistor by color band one at a time.

    I cannot easily distinguish colors from your photo but for starters R3 does not appear to be correct.

    #29874
    M. E. Moriearty
    Participant

    Sorry, flash on cheap resistors. I miss my old batch.
    Should be 68k, blue grey black red brown. I’ll grab the MFT and get to work once I get home.

    #29877
    M. E. Moriearty
    Participant

    R3 is spot on 68k.
    However, this batch either has some mislabels, bad QC, or burn extremely easily. They’re from Amazon.
    R5, R6, R15, and R21 are all reading either half or twice what they should. From here on out, everything meets the tester ahead of time.
    Well this is going to be a project.

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