Current Lover Calibration

Started by meyerdanielw, June 26, 2017, 11:42:34 PM

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meyerdanielw

I'm building a 2015 Mad Bean Current Lover, and I'm having a difficult time with the calibration. I've followed the instructions in the build guide thus far, but I'm having a hard time finding a good spot on the bias trimmer. I'm getting either no flanging at all or noise. The build guide references a "chirping" sound at the extremes, but what I'm getting can only be described as an earsplitting squeal. I can crank the volume down and just let it squeal without blowing out my ear drums, but there's no place within the range of the clock trimmer that I can eliminate that noise. If however I skip ahead in the process a bit and adjust the T1 trimmer clockwise I can eliminate the squeal, but then the guitar signal is distorted (I'm playing a fender with humbuckers) I tried to replace R1 with a larger value, but that hasn't cleaned up the sound at all, and I tried replacing R10 with a smaller value but that just compressed the same range of flaging effect into a smaller arc of the trim pot's range of adjustment. I know that the clock trimmer is supposed to be important to the calibration process according to the build guide, but it seemingly has almost no effect. I've tested the voltages at all of my IC pins. I'm in the right neighborhood on all but the 7th pin of IC5. The build guide says that pin should be at 7.8v, but I'm reading 0. I took a look at the circuit diagram and the way I'm reading it  it doesn't even look like pin 7 is connected to the circuit. The rate knob indicator LED is also lit up even when the pedal is disengaged. Is that normal? Those are my only two clues that something might be wrong with my build, but I don't know what to make of them. There might be nothing wrong for all I know and this is just how the pedal sounds when you play high output humbuckers through it (I don't have a guitar with single coils). Any help is appreciated. Thanks


duck_arse

I can't help except to say your images don't show.
You hold the small basket while I strain the gnat.

antonis

Quote from: duck_arse on June 27, 2017, 11:08:24 AM
I can't help except to say your images don't show.
Thought it was only me with advanced blindness.. :icon_biggrin:
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

meyerdanielw


GibsonGM

Hi Daniel...we'll need to see the instructions you are working from, bud!  Probably not a big deal, but without something to go by we're sort of lost here...
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meyerdanielw

Sorry about that. I originally posted this on the same forum that I purchased the PCB from so everyone was kind of on the same page. Below are the calibration instructions and at the end is a link to the entire build guide.

QuoteThe Current Lover must be correctly calibrated to function properly. This is done with the Clock and Bias trimmers. These
work independently from one another but require some re-adjustments as you work through calibration. The Clock
trimmer is very sensitive to fine adjustment so be prepared to spend a few minutes getting the right setting.
Before powering up the board and connecting your guitar and amp, set the Clock and Bias trimmers to their middle
position. Set the T1 trimmer and Rate pot fully counter-clockwise. Finally, set the Range, Volume and Feedback pots to
approximately their middle positions and the Filter switch to the right position. Now connect the board between your guitar
and amp and power it up. You should get signal through the effect, although you may not hear any flanging yet. If you do
not have any signal, double check your connections and ensure that there are no bugs in your build.
First adjust the Bias trimpot until you get some flanging. You don't have to be precise, just get the BBD working. Next
adjust the Clock trimpot to the point where you achieve a wide sweep with minimum noise. If the flange starts to whine or
"chirp" at the extremes of its sweep you will need to do a little more adjustment. Go back and tweak the Bias trimpot
further clockwise until you get smooth up and down flange without distortion. Set the Feedback control fully clockwise and
gently adjust T1 clockwise until you get the maximum feedback desired (T1 acts as a limit to the maximum allowed
feedback). Continue making minor adjustments to the trimmers while testing the limits of the Rate, Range and Feedback
controls. Describing this process makes it seem more complicated than it actually is: your ear will be the guide in
achieving the best sound across the widest range of control settings.
The most important thing to balance here is the Clock trimmer. You need to make sure you get no "chirpping" at the
extremes of flanging when you set the Range, Fdbk and Rate pots fully up. Like I said before...very minute adjustments to
the Clock trimmer make a big difference. Most of the adjustment will occur in the first ΒΌ turn of the trimmer

http://www.madbeanpedals.com/projects/CurrentLover/CurrentLover_2015.pdf