Zeppelin Design Labs

Extra noise

This topic contains 5 replies, has 3 voices, and was last updated by  brach 3 days, 14 hours ago.

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  • #15115 Reply

    jrg320
    Participant

    I built my Quaverato a few months ago, and I generally really enjoy the sound pedal, but I have been getting an extra high-pitched frequency in the signal when I have the pedal in the signal, whether it is engaged or in bypass, and the sound corresponds to the rate at which the trem is set. Again, this is happening both in bypass and engaged mode, but won’t happen if the depth is all the way down, which of course is no longer a trem-pedal, but a very large boost (I’ve actually been using it as a last-stage boost lately, because the trem causes too much noise!)
    Any thoughts on how I can alleviate this?

    #15136 Reply

    brach
    Moderator

    This sounds like either the PWM is leaking into the signal path or the power supply is noisy. First of all, try to switch power supplies to a liner type (instead of switch-mode)…make sure it’s rated for at least 100mA. See if this helps.
    If the PWM is leaking into the signal path, this can usually be helped by adjusting the high and low trim pots down in volume. Also play around with the gain trim pot to adjust the ratio of high/low trim pot volume to gain trim pot volume. This noise should decrease as you get the trim pots set in a good ratio.
    Good luck.
    -Brach

    #15475 Reply

    mike335
    Participant

    I’ve been trying to optimize my Quaverato’s internal high, low, and gain trim pot settings to minimize noise and set the best tone for my tastes/purposes. I bought my kit and downloaded the owner’s manual and assembly instruction .pdf’s some time ago. After building it, it worked, but was a bit noisy, at least with my single-coil guitars.

    When I opened the case up some months after completing the build I reviewed the owner’s manual and assembly instruction .pdf’s and found that there appears to be a discrepancy between these two documents in regards to the gain trim pot. The owner’s manual says on page 13: “Turning this pot clockwise increases the gain, counterclockwise decreases the gain.” The assembly manual on the other hand says on page 44: “the volume output of the pedal should be roughly the same when the effect is bypassed or engaged [with the volume knob at 12:00]. If not, adjust the GAIN trim pot (VR10) until it is. Counterclockwise gives more gain, clockwise gives less gain.” The instructions for the high and low trim pots that I found on page 45 of the assembly manual state: “If you would like the tone to be a little brighter then turn up the HIGH trim pot (clockwise) and turn down the LOW trim pot (counterclockwise). If you would like the tone to be a bit darker do the opposite: turn down the HIGH trim pot (counterclockwise) and turn up the LOW trim pot (clockwise).”

    To tell the truth, turning the screw on the trim pots doesn’t really seem to do a great deal to change the gain with the gain trim pot or tone with the low and high trim pots. They don’t seem to have any stops, and the changes seem almost imperceptible. If rotating the screw on the gain trim pot counterclockwise increases gain, I would have thought that the same applies to the high and low trim pots, I gather this is incorrect, and that to increase the high or low end tone with the high and low trim pots requires turning the screws clockwise?

    Frankly I’m a bit confused about making the adjustments. I don’t really want to desolder the jumpers to reset the resistance with my meter according to the assembly instructions, but I guess it might be smart to do that and start over from the recommended baseline.

    #15517 Reply

    brach
    Moderator

    Mike335,
    I’m sorry for the confusion.
    Thank you for pointing out this discrepancy between the Quaverato user manual and assembly manual.
    The assembly manual is correct. The gain increases as you turn the gain trim pot counter clockwise. The tone trim pots are just the opposite, clockwise increases volume output.
    These are 25-turn trim pots…so you probably won’t notice much change if you only turn it a little bit…at least with the gain trim pot. You just have to keep turning it until you hear the volume change. As you keep turning it, there will be one area that it really starts to change and you’ll notice it. You’re right, they don’t have any stops to them so once you get to the end of the pot’s 25 turns it starts making a little clicking sound as you turn it, indicating it’s not adjusting anymore.
    You probably don’t need to unsolder the jumpers to reset the tone trim pots…just use your ears. It also may help to use “calibration mode” to set the tone trim pots. The gain trim pot can always be tested via test points 5 and 6, as long as the pedal is off.
    Once again, sorry for the confusion.
    Let me know if you have any more questions.
    -Brach

    #15526 Reply

    mike335
    Participant

    Brach,
    Thanks for clarifying how the Quaverato’s internal trim pots work. I’ve been making adjustments to them with the Quaverato powered up face down on my bed with the back off of the case so that I can play and hear how the adjustments affect the volume/tone. It’s been a bit confusing, probably because I didn’t know that these little pots are 25-turn pots, and the changes are subtle. I haven’t noticed any “clicking sounds”, presumably because I haven’t reached the end of the 25-turn range, I don’t know. At least now I can be sure of the correct direction to turn them.

    Thanks for the help.
    Mike

    #15546 Reply

    brach
    Moderator

    Mike,
    Once again, sorry for the confusion and the misleading/wrong info in the user manual.
    Keep playing with the trim pots. Hopefuly you’ll find a setting that works for you.
    Let me know if you have anymore questions.
    -Brach

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